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. 2020 Sep 11;15(9):e0237934. doi: 10.1371/journal.pone.0237934

Enhancing feelings of security: How institutional trust promotes interpersonal trust

Giuliana Spadaro 1,*, Katharina Gangl 2,3, Jan-Willem Van Prooijen 1,4, Paul A M Van Lange 1, Cristina O Mosso 5
Editor: Valerio Capraro6
PMCID: PMC7486136  PMID: 32916694

Abstract

Interpersonal trust is an important source of social and economic development. Over decades, researchers debated the question whether and how public institutions influence interpersonal trust, making this relationship a much-discussed issue for scientific debate. However, experimental and behavioral data and insights on this relationship and the underlying psychological processes are rare and often inconsistent. The present set of studies tests a model which proposes that institutional trust indirectly affects trust among unrelated strangers by enhancing individuals’ feelings of security. Study 1 (survey on trust in a broad spectrum of state institutions), Study 2 (nationally representative data from 16 countries), and Study 3 (experimental manipulation of institutional trust) provide convergent support for this hypothesis. Also, the results show that the effect remains consistent even after controlling for individual dispositions linked to interpersonal and institutional trust (Study 1 and 3) and country level indicators of institutional performance (Study 2). Taken together, these findings inform and contribute to the debate about the relationship between institutions and interpersonal trust by showing that when institutions are trusted, they increase feelings of security, and therefore promote interpersonal trust among strangers.

Introduction

Trust among citizens is crucial for the societal, political, and economic functioning of a state [1]. Societies with high interpersonal trust have happier citizens [2], more political participation [3], and stronger economic growth [4]. Traditionally, trust is deeply rooted in social interaction in dyads and small groups. However, those interactions do not occur in a social vacuum, as they are directly or indirectly embedded in a societal context regulated by institutions, which constitute “rules of the game” that structure social life [5].

In the last two decades, research has been conducted to understand whether certain features of the institutional setting (e.g., performance, efficiency, and fairness) can favor the development of interpersonal trust among strangers [610], often leading to opposite predictions [11]. Also, little empirical evidence for the key mechanisms underlying a presumed association between institutions and interpersonal trust is provided in the research literature (e.g., [12]), largely relying on survey studies within one particular society and a limited set of institutions. In the present research, we contribute to this body of literature by focusing on individuals’ perceptions of institutions and, more specifically, testing the hypothesis that institutional trust can stimulate trust among strangers by enhancing feelings of security. Across three studies (a survey, an analysis of a cross-national database, and an experimental study), we tested a model proposing that institutional trust fosters interpersonal trust as it serves as cue conveying that one is not completely at the mercy of potentially hostile strangers, but rather is protected in case strangers have malevolent intentions.

Interpersonal trust and institutions: Crowding-out and institution-centered approaches

Interpersonal trust is a pervasive phenomenon of social life and a lubricant for many societal processes. It is defined as a psychological state that involves the intention to accept vulnerability in social interactions, under conditions of social risk and interdependence [13,14]. It is often conceptualized as a multidimensional construct that can be differentiated into trusting beliefs and the resulting trusting intentions or behavior [1517]. The former refer to individuals’ perceptions of trustworthiness of others, while the latter reflect the acceptance of vulnerability and actions undertaken to gain possible advantages [18]. Positive expectations regarding the intentions or behavior of one or more persons are often based on own direct experience or reputational information shared by others [1921]. Such interaction processes are key to the development of trust and, thus, to people’s willingness to accept risk in situations often characterized by strong interdependence (e.g., [18,22]; for reviews see [23,24]). However, in modern complex societies, individuals often face interactions with strangers, in situations where trust is unlikely to be based on social interactions or reputational information shared by others. Here formal institutions, conceptualized as external systems of control that offer “rules of the game”, help to structure and increase the predictability of such exchanges [5]. Indeed, state institutions such as public administration or the police provide safeguards ensuring that others behave cooperatively, and therefore offer cues that increase trust in others [11].

The relationship between institutions and interpersonal trust has been debated, however, especially in light of institutions’ key role in providing rules and normative expectations [7,11]. The main claim of the so-called crowding-out approaches is that interpersonal trust becomes no longer relevant if institutions are in place. External sources of control as sanctioning systems directly affect the incentive structure of the interaction by increasing the cost of non-cooperative actions. As a consequence, such institutions remove the social uncertainty involved in the social exchange, and expectations and actions become driven by assurance rather than interpersonal trust [25]. While interpersonal trust is based on beliefs about the benevolent and intrinsic motivation of the partner, assurance is based on the expectation that the interaction partner will behave according to the relevant incentive structure, thus crowding-out interpersonal trust and voluntary cooperation [26]. Moreover, the mere need to establish such systems can even be considered as a signal of others’ untrustworthiness and, therefore, decrease the motivation to trust [27]. Also, findings from cross-cultural research make similar claims, showing that individuals in societies that differ along the tightness-looseness dimension (i.e., the strength of social norms and the tolerance of deviance) manage their relationships differently in terms of interpersonal trust. Individuals in tight societies, compared with loose ones, tend to rely on strongly defined norms that provide clear expectations enforced through external control systems [28,29], while those in loose cultures, where rules and regulations are less prevalent, are more likely to rely on interpersonal trust instead [30].

On the other hand, a different theoretical perspective considers formal institutions as laying the ground for the development of interpersonal trust, especially when there is high level of uncertainty about others’ beliefs and norms [31]. Accordingly, institutions initially enforce trustworthy interactions through external rules, but after repeated successful interactions, individuals would not rely on mere assurance anymore, generalizing their beliefs about others’ benevolence to other settings [32]. In fact, evidence shows that societies with efficient institutions, operationalized for example as societies with high level of democracy or effectiveness in enforcing agreements between strangers, display greater levels of interpersonal trust, as compared to countries with inefficient institutions [7,9].

The relationship between institutional and interpersonal trust

Importantly, together with the quality of the institutions, individuals’ perceptions and subjective assessments based on existing information of institutions might play a major role in understanding how institutions affect trust and the underlying mechanisms. Indeed, existing empirical evidence shows that, compared to institutional quality indicators, perceptions of institutions are similarly associated to interpersonal trust. For example, citizens’ perceptions of institutional fairness or perceptions of corruption are related to interpersonal trust as do country-level indicators of fairness (e.g., skewness of income distribution) and corruption (e.g., number of arrests for corruption) [33,34]. Thus, it is possible to assume that, although in some situations external institutions may undermine interpersonal trust, this effect is conditional to whether people perceive them as legitimate and trustworthy (e.g., [35,36]). That is, taking into account whether these institutional constraints are trusted themselves can be crucial for understanding how they affect interpersonal trust. Indeed, institutional trust, defined as the extent to which individuals accept and perceive institutions as benevolent, competent, reliable, and responsible toward citizens [37], has been proposed as especially relevant for sustaining interpersonal trust [38,39]. For individuals, trusting institutions involves the perception that institutions would act in accordance to the common interest and society’s needs to resolve disputes [40,41]. Recent evidence drawn from survey studies suggests that countries with high institutional trust are also characterized by more interpersonal trust [42,43]. This correlation appears robust across different countries and institutional settings, e.g., in Europe [44], Asia [45,46], and the USA [47], suggesting that these two types of trust are interrelated, with institutional trust influencing interpersonal trust. Given the observational nature of these studies, some authors argue that this relationship might actually be reversed (i.e., with interpersonal trust influencing institutional performance; e.g., [48]) or of mutual influence (e.g., [49]), while other more recent studies with individual fixed effects and cross-lagged panel models suggest that this is unlikely, and that institutional trust has an impact on interpersonal trust (e.g., [44,5052]). Institutional trust has also been proposed as a mediator mechanism to explain how quality of institutions relates to interpersonal trust. For example, in a recent study, Lo Iacono showed that the ineffective institutions mostly affected interpersonal trust via a decrease in institutional trust [38]. Similarly, in a pilot study we found that institutional trust mediated the relationship between the presence (vs. absence) of institutions and trusting beliefs and behavioral intentions (methods and results are presented in detail in S1 Appendix in S1 File).

Although the existence of a relationship between institutional trust and interpersonal trust has been extensively discussed (e.g., [39]), empirical evidence to illuminate the underlying processes is scarce. In a pioneering experiment, Rothstein and Eek [53] manipulated corruption with scenarios describing corruption of institutional representatives in a fictitious country in order to test the effect of institutions on interpersonal trust. In this study, student participants from Sweden and Romania were exposed to eight vignettes which respectively manipulated a bribe (present or absent), the initiator (the authority or the citizen), and the outcome of the exchange (positive or negative). The results showed that when public authorities were depicted as corrupt, participants perceived fellow citizens in the scenario as less trustworthy. The authors of the study further speculated that this effect could be explained by an inference-based underlying mechanism. Accordingly, individuals would make generalized inferences about others’ trustworthiness based on observations of corrupt behavior enacted by public officials, others, and even themselves, interpreting these signals as information about what type of “game” is being played in a society [53,54]. Up to date, this remains the only experimental evidence available. However, the authors did not test the mechanisms underlying this effect, nor did they test the implications for trusting behavior. As such, little is still known about the question of whether institutional trust influences interpersonal trust beliefs and behavior toward unrelated strangers, or what underlying processes are responsible for this relationship. The present studies were designed to fill this void and to provide preliminary evidence for a potential underlying mechanism that might inform this debate.

The mediating role of feelings of security

Previous literature suggests that, among their other functions, institutions have a crucial role for individuals to achieve security and safety in life [55,56]. Benevolent institutions provide structure in society, which allows individuals to achieve a greater sense of control over their lives [57]. Indeed, individuals are motivated to avoid victimization and exploitation from others [58] and to pursue safety and security by reducing personal threats in social situations [59]. Accordingly, institutions related to law and order may lead citizens to experience generalized feelings of security that would make them feel protected from potential offenses perpetrated by other fellow citizens [60]. We define these feelings as individuals’ generalized perception of how safe they feel and to what extent they feel protected from socially threatening events. Additionally, we propose that when challenged by threats, feelings of security may be influenced by cues of trustworthiness of formal institutions, such as encounters with corrupt public officials or witnessing corrupt exchanges between other citizens and public representatives, as they provide a strong signal that social order is not guaranteed [53,60]. When it comes to interpersonal trust, there is evidence that general emotional states play a role [61], but, in particular, feelings of security are relevant to build interpersonal trust because they lead individuals to feel less vulnerable, which is key in trusting interactions with unknown strangers [14].

Law and order institutions are specifically related with protecting one’s personal safety, but also social institutions [56], religious institutions [62], or the government [12] have been proposed to serve this motive and affect individuals’ feelings of security. Despite the underlying role of feelings of security has never been investigated in previous research, other indirect empirical evidence is also in line with this assumption. In experiments, individuals prefer to interact in settings where sanctioning and rewarding institutions are in place [63]. These institutionalized societal models are particularly effective in mitigating people’s fear of exploitation and, thus, to establish a culture of cooperation over time [64]. Further evidence in this vein comes from survey research, suggesting that efficient institutions promote less parochial behavior and more interpersonal trust [55]. Moreover, recent survey data support the protective function of trust toward governmental and legal institutions in Sweden focusing on fear of crime [12], showing that crime-related insecurity mediated the relationship between institutional trust and interpersonal trust.

The current studies

The aim of the current three studies is to provide a first experimental and cross-country test for the hypothesis that institutional trust indirectly promotes trust among strangers by providing feelings of security, which in turn allow people to accept vulnerability and to trust others. Fig 1 summarizes the model tested across all studies, as well as the expected relationships between the constructs. In Studies 1 to 3, we tested whether feelings of security mediate the relationship between institutional and interpersonal trust. In Study 1, through a survey, we investigated whether trust in several formal institutions is related to feelings of security, and subsequently, to interpersonal trust. In Study 2, we tested our model with a multilevel mediation analysis on European Social Survey data (ESS; [65]) across 16 countries. Finally, in Study 3, we addressed the same hypothesis by directly manipulating institutional trust in a between-subjects experimental design. Additionally, in Study 3 we also test an alternative mediation model, according to which institutional trust affects interpersonal trust through an increase of the expectations about other’s behavior. For an overview of the different operationalizations of the constructs used to test the model across all studies, and their descriptive statistics, see S1 Table in S1 File.

Fig 1. The model: Institutional trust as a predictor of interpersonal trust (trusting beliefs and subsequent behavior) via feelings of security.

Fig 1

To establish the robustness of our results, all studies included control variables to account for variation in the dependent measure. Indeed, the lack of control for stable psychological dispositions in previous cross-sectional studies might have overestimated the relationship between the two forms of trust in the past (see [39]). In Studies 1 and 3, we controlled for individual dispositions related to interpersonal and institutional trust, namely trust propensity, political orientation, and security values. Trust propensity is a stable individual disposition, defined as a generalized expectation about others’ trustworthiness, and one of the most significant predictors of trust in interactions with strangers [13,66]. This variable was included in Study 1 and 3 to disentangle that trusting beliefs and behavior toward a specific target did not depend on an underlying general willingness to trust others. Right-wing political orientation and, more generally, conservative ideology [67] may both be associated with the need to reduce uncertainty and support of external control systems [68]. The endorsement of security values characterizes individuals who prioritize security and predictability [37] and, therefore, are more likely to prefer strong institutions. In Study 2, we included country-level indicators of institutional performance that strongly correlate with both institutional and interpersonal trust (e.g., political and economic performance; [69]).

Study 1

In Study 1, we aimed to extend findings on the relationship between institutional trust and interpersonal trust by providing a preliminary first test of the hypothesis that institutional trust promotes interpersonal trust toward strangers by enhancing individuals’ feelings of security. In doing so, we used a cross-sectional survey design that analyzed trusting beliefs toward state institutions and fellow citizens. Additionally, we assessed institutional trust toward a large set of public institutions to identify whether the perceiving feelings of security would be relevant for specific institutions (such as those absolving more monitoring or sanctioning functions) or generalizable across institutional settings. Unlike previous observational studies that use single items to measure institutional trust, institutional trust was measured through scales covering perception of competence, benevolence, and integrity [70], to overcome single-items psychometric limitations (e.g., random measurement errors and biases in interpretation).

Materials and methods

Participants

The sample consisted of 181 Italian participants (75.7% female; Mage = 28.06, SDage = 9.74). Most of them had bachelor’s degree (40.3%) and described themselves as slightly left-wing on a 10-point political orientation scale ranging from left to right (M = 4.06, SD = 2.31). The participants’ regions of origin were proportionally distributed among north (43.1%), center (14.9%), and south Italy (42%). To ensure that all participants had some degree of experience or previous information about Italian public institutions, we recruited participants being at least 18 years of age, and excluded participants that reported to have a different nationality (N = 1). Sensitivity analysis revealed that this sample size would result in 80% statistical power to detect a small effect of institutional trust on trust beliefs (f 2 = 0.04; [71]). The whole research was conducted in accordance with the Declaration of Helsinki (7th revision, 2013) and local ethical guidelines for experimentation with human participants and was approved by the institutional review board at the University of Turin and by the ethical commission of the Zeppelin University in Friedrichshafen. All participants gave written informed consent prior to the experiments.

Procedure

Participants were recruited on social media through a snowball sampling. They accessed to the online survey through a call for participation posted on social media accounts and were requested to share the call with others. The study included measures of trust toward different state institutions, interpersonal trust, feelings of security enhanced by public institutions, security values, trust propensity, and a socio-demographic section. To avoid sequence effects, all items were presented in a randomized order within each scale and, unless otherwise stated, they were answered on a seven-point Likert scale from 1 (I completely disagree) to 7 (I completely agree).

Institutional trust

We assessed trust in five different institutions related to social order ([70], eight items for each institution, e.g., “I trust the police in Italy because they behave benevolently toward citizens”, police: α = .81; legal system: α = .84; government: α = .81; media: α = .82; religious institutions: α = .87). Following Agroskin, Jonas, and Traut-Mattausch [72], in addition to the items proposed in the original scale, we presented an additional item to increase the scale validity (i.e., “I generally trust the police in my country”). Following previous research on institutional trust (e.g., [73]), we then additionally averaged the scores of these five scales in a single cumulative index of institutional trust, which showed a good reliability, α = .70.

Interpersonal trust

Trusting beliefs toward Italian citizens were measured through an adaptation of General Trust Scale ([25]; six items, e.g., “I believe that Italian citizens are basically honest”, α = .93). This scale consisted in a series of questions that assessed to what extent respondents perceived fellow citizens as trustworthy.

Feelings of security

We included a measure of feelings of security that individuals experience in relation to institutional performance and representatives (three items, i.e., “I feel protected by public institutions”, “I am comforted by thinking that I can count on public institutions if anything happens to me”, “I feel I can rely on public institutions to assert my own rights”, α = .89).

Control variables

As control variables, we measured trust propensity through the Trust in Others Scale ([74]; three items, e.g., “I dare to put my fate in the hands of most other people”, α = .65) and the endorsement of security values using the respective subscale from the Portrait Values Questionnaire [75]. Here respondents are asked to indicate own perceived similarity to a described person (five items, e.g., “It is important to him to live in secure surroundings. He avoids anything that might endanger his safety”, α = .74) on a six-point Likert scale from 1 (not like me at all) to 6 (very much like me).

Results

Results showed the expected significant associations between average and distinct trust in the five institutions, feelings of security, and trusting beliefs toward citizens (S2 Table in S1 File). Additionally, the individual dispositions used as controls confirmed the hypothesized association with both interpersonal trust and institutional trust. The Pearson’s correlation analyses also showed associations between trust propensity and interpersonal trust (r = .39, p < .001), the endorsement of security values and institutional trust (r = .22, p = .003), and right-wing political orientation and trust toward the police (r = .27, p < .001) and religious institutions (r = .21, p = .006), respectively. We also found a medium correlation between institutional trust and feelings of security (r = .50, p < .001), suggesting a possible partial overlap between the two constructs. However, confirmatory factor analyses showed that this is unlikely, and that security and institutional trust are separate factors (statistical details are reported in Table A in S2 Text in S1 File).

The main effect of institutional trust on interpersonal trust

We conducted a simple linear regression with institutional trust (average trust in all five institutions) predicting trusting beliefs. Institutional trust significantly predicted trust toward fellow citizens (interpersonal trust), F(1, 179) = 15.29, p < .001, R2 = .08.

The indirect effect of institutional trust on interpersonal trust via feelings of security

A mediation analyses with 5,000 bootstrapped samples using the SPSS macro Process model 4 [76] showed that the indirect effect of institutional trust on trusting beliefs towards other citizens is significant for each of the five institutions under analysis: police (b = 0.12; 95% CI [0.05; 0.21], R2 = .12), legal system (b = 0.14; 95% CI [0.06; 0.24], R2 = .11), government (b = 0.13; 95% CI [0.06; 0.23], R2 = .12), religious institutions (b = 0.04; 95% CI [0.01; 0.09], R2 = .02), and the media (b = 0.09; 95% CI [0.04; 0.16], R2 = .12). Overall, the relationship between institutional trust and trusting beliefs towards fellow citizens was mediated by feelings of security while considering the aggregate index of institutional trust as a predictor in the model, b = 0.18; 95% CI [0.06; 0.32], R2 = .13. These results appeared robust even if trust propensity, security values, political orientation, and education were included as controls in the analyses, b = 0.15; 95% CI [0.05; 0.27], R2 = .26. Detailed results of the mediation models are presented in detail in Table 1.

Table 1. Results of mediation models for the effect of institutional trust (aggregate measure and single institutions) on interpersonal trust through feelings of security.
Predictor and effect Outcome: Trusting beliefs
Model 1 Model 2
b SE 95% CI b SE 95% CI
Mediator: Feelings of security 0.23 0.07 0.08; 0.37 0.19 0.07 0.05; 0.33
Predictor: Institutional trust (Aggregate)    
Total effect 0.39 0.10 0.19; 0.59 0.29 0.10 0.10; 0.49
Direct effect 0.21 0.11 -0.01; 0.44 0.15 0.11 -0.07; 0.37
Indirect effect 0.18 0.06 0.06; 0.32 0.15 0.06 0.06; 0.27
Mediator: Feelings of security 0.25 0.07 0.11; 0.39 0.19 0.07 0.06; 0.33
Predictor: Institutional trust (Police)    
Total effect 0.25 0.07 0.10; 0.40 0.22 0.08 0.07; 0.36
Direct effect 0.13 0.08 -0.03; 0.29 0.11 0.08 -0.06; 0.27
Indirect effect 0.12 0.04 0.05; 0.21 0.11 0.04 0.04; 0.20
Mediator: Feelings of security 0.26 0.07 0.12; 0.41 0.2 0.07 0.06; 0.34
Predictor: Institutional trust (Legal system)    
Total effect 0.22 0.07 0.08; 0.36 0.18 0.07 0.05; 0.31
Direct effect 0.08 0.08 -0.08; 0.23 0.07 0.08 -0.08; 0.22
Indirect effect 0.14 0.05 0.06; 0.24 0.11 0.04 0.03; 0.19
Mediator: Feelings of security 0.26 0.07 0.12; 0.40 0.20 0.07 0.07; 0.34
Predictor: Institutional trust (Government)    
Total effect 0.24 0.08 0.09; 0.39 0.19 0.07 0.04; 0.33
Direct effect 0.11 0.08 -0.06; 0.27 0.09 0.08 -0.07; 0.24
Indirect effect 0.13 0.04 0.06; 0.23 0.10 0.03 0.04; 0.18
Mediator: Feelings of security 0.28 0.06 0.16; 0.41 0.23 0.06 0.11; 0.35
Predictor: Institutional trust (Religious institutions)    
Total effect 0.12 0.06 0.01; 0.25 0.06 0.06 -0.06; 0.18
Direct effect 0.09 0.06 -0.03; 0.20 0.03 0.06 -0.09; 0.15
Indirect effect 0.04 0.02 0.01; 0.09 0.03 0.02 -0.01; 0.07
Mediator: Feelings of security 0.27 0.07 0.14; 0.40 0.22 0.06 0.10; 0.35
Predictor: Institutional trust (Media)    
Total effect 0.21 0.08 0.06; 0.37 0.14 0.08 -0.01; 0.30
Direct effect 0.13 0.08 -0.03; 0.28 0.07 0.08 -0.9; 0.22
Indirect effect 0.09 0.03 0.04; 0.16 0.07 0.03 0.03; 0.14

Results based on 181 observations. Model 1: Mediation analyses did not include control variables. Model 2: Mediation analyses included trust propensity, security values, political orientation, and education as control variables.

Discussion

The findings of Study 1 are in line with previous studies and our key hypothesis. Institutional trust was associated with interpersonal trust, and this relationship was mediated by the feeling that institutions can protect individuals from the exploitative behavior of strangers. This indirect effect appeared to be independent from individual dispositions. Moreover, Study 1 showed that this indirect effect was consistent over all the five main public institutions related to social order, even for those that do not directly deal with monitoring or sanctioning (e.g., the media). However, religious institutions seemed to play a more marginal role, as suggested by the magnitude of the effect size and the fact that the indirect effect becomes non-significant after control variables were added.

Study 2

Study 1 provided initial evidence for the hypothesis that institutions, when trusted, are associated with feelings of security, which in turn predict trust in strangers. However, our results were limited to relatively small and non-representative samples from a single country and institutional context (i.e., Italy). In Study 2, we filled this gap by testing this hypothesis across 16 countries. Importantly, the current study presents different operationalizations of feelings of security and interpersonal trust. Feelings of security were measured as perception of personal safety. This measure is not explicitly tied to the specific institutions under investigation as in Study 1, but it is particularly relevant for institutions that are supposed to regulate social exchange and safeguard law and order. A different operationalization of feelings of security also allows to further generalize the findings and disentangle any possible overlap with the construct of institutional trust. Interpersonal trust has been assessed using respondents’ scores on the Generalized Trust Scale. Differently from Study 1, the current trust measure does not involve a specific target of the trusting beliefs, but rather reflects beliefs toward “most people”, that are likely to drive behavior in contexts involving unfamiliar actors. This different operationalization of interpersonal trust allows to relate our findings to previous evidence from survey studies using this scale (e.g., [43]) and to generalize them above specific trust targets (i.e., members of own community such as Italian citizens in Study 1). Finally, we included several control variables specifically related to both respondents’ trust-relevant socio-demographic characteristics and institutional performance.

Materials and methods

Participants and procedure

This study used data from the European Social Survey (ESS). In total, answers from 180,051 participants (50.65% female; Mage = 47.27, SDage = 18.04) from 16 countries of the European area (Belgium, Switzerland, Germany, Denmark, Spain, Finland, France, United Kingdom, Hungary, Ireland, Netherlands, Norway, Poland, Portugal, Sweden, and Slovenia) were included in the analysis. Most respondents completed upper secondary education (35.7%) and described themselves as politically moderate (M = 5.08, SD = 2.11) on a bipolar 11-point scale from 0 (left-wing) to 10 (right-wing). ESS data are gathered through cross-sectional face-to-face individual interviews administered to nationally representative samples, with different samples recruited for each wave. To provide greater temporal stability of the theoretical assumption, we decided to include only those countries participating to all survey waves (1–7) from 2002 to 2014, as well as only respondents without missing values in the variables described below (initial and final sample sizes and main descriptive statistics for each country are reported in S3 Table in S1 File). For the present analysis, we selected measures of trust in different state institutions, interpersonal trust, feelings of security, and country level indicators of institutional performance.

Institutional trust

As in Study 1, we obtained the measure of institutional trust by aggregating trust ratings toward four state institutions (i.e., “How much you personally trust the parliament”, “the legal system”, “the police”, and “the politicians”, α range among countries = .78 - .87). Individual responses were given on a 11-points Likert scale, ranged from 0 (no trust at all) to 10 (complete trust).

Feelings of security

The study contained a single-item measure as a proxy for respondents’ feelings of security (i.e., “How safe do you—or would you—feel walking alone in this area after dark?”). Answers have been reverse-scored to allow consistent interpretation with the three-items measure used in Study 1, thus ranging from 1 (very unsafe) to 4 (very safe).

Interpersonal trust

Interpersonal trust was assessed using the Generalized Trust Scale (three items, e.g., “Generally speaking, would you say that most people can be trusted, or that you can’t be too careful in dealing with people?”, α range = .63 - .77). As for institutional trust, each item was answered on a 11-points Likert scale from 0 (no trust at all) to 10 (complete trust), phrased according to the specific item from 0 (you can’t be too careful) to 10 (most people can be trusted).

Control variables

Last, country-level indicators of institutional performance of political and economic institutions were retrieved from established databases for each of the countries under investigation (i.e., government effectiveness, political rights, rule of law, economy competitiveness, GINI, and GDP per capita) from available time points between wave 1 and 7 of the ESS (2002–2014). A detailed description of these indicators is provided in S2 Appendix in S1 File.

Results

First, data were corrected for sampling errors, since the ESS data involved respondents from multiple countries. By applying the design weight variable (dweight) included in the ESS dataset, we adjusted for the differences in the chance of selection of respondents for each country in all the following analyses. Moreover, control variables were included in the models in two steps, with respondents’ trust-relevant socio-demographic characteristics (i.e., age, gender, and education) being included first, followed by institutional performance indicators at a second stage. We report results from both analyses.

The indirect effect of institutional trust on interpersonal trust via feelings of security

To test our main prediction that institutional trust predicts interpersonal trust through increased feelings of security, we performed multilevel mediation analyses with bootstrapping method with the R package mediation [77,78] to account for the nested structure of the ESS data. In this model, respondents (level-1) are nested within countries (level-2). The mediation functions took as an input two multilevel regression models. The first multilevel regression had institutional trust as independent variable and feelings of security as dependent measure with countries as random intercept. The independent variables of the second multilevel regression were institutional trust and feelings of security, while the dependent variable was interpersonal trust, again with country as random intercept.

In line with the hypothesis, the results showed that the feelings of security had a significant indirect effect in interpersonal trust, b = 0.013, 95% CI [0.0117; 0.0136] controlling for survey wave and common sociodemographic variables associated to interpersonal trust in survey research (i.e., gender, age, and education; e.g., [79]). The relationship was partially mediated since the effect of institutional trust on interpersonal trust, b = 0.342; 95% CI [0.3377; 0.3458], remained significant when the mediator was included in the model, b = 0.329; 95% CI [0.3251; 0.3325]. Moreover, the results showed that including institutional performance indicators (e.g., GDP per capita, government effectiveness, and rule of law) as covariates in the multilevel mediational analysis did not affect the significance of the model, b = 0.013; 95% CI [0.0123; 0.0145]. While controlling for institutional performance indicators, the effect of institutional trust on interpersonal trust, b = 0.352; 95% CI [0.3484; 0.3563], remained significant when the mediator was included in the model, b = 0.339; 95% CI [0.3354; 0.3424]. Results of the multilevel mediation models are presented in detail in Table 2.

Table 2. Results of the multilevel mediation models for the effect of institutional trust (aggregate measure) on interpersonal trust through feelings of security.
Predictor and effect Model 1 Model 2 Model 3
b 95% CI b 95% CI b 95% CI
Mediator: Feelings of security 0.298 0.2978; 0.2984 0.326 0.3260; 0.3265 0.296 0.2954; 0.2962
Predictor: Institutional trust (Aggregate)      
Total effect 0.352 0.3479; 0.3564 0.342 0.3377; 0.3458 0.352 0.3484; 0.3563
Direct effect 0.339 0.3347; 0.3421 0.329 0.3251; 0.3325 0.339 0.3354; 0.3424
Indirect effect 0.013 0.0121; 0.0144 0.013 0.0117; 0.0136 0.013 0.0123; 0.0145
% of Total effect 0.04 0.04 0.04

Results of all models are based on 180,051 observations and use countries as random effects. % of Total effect: Proportion mediated (i.e., ratio of the total effect to the indirect effect).

Model 1: Mediation analyses included survey wave as control variable. Model 2: Mediation analyses included survey wave and individual-level variables (gender, age, and education) as control. Model 3: Mediation analyses included survey wave and country-level variables (political rights, government effectiveness, rule of law, economy competitiveness, GINI coefficient, and GDP per capita) as control.

As in Study 1, we also run our models considering trust in the four different institutions, instead of a single aggregated measure. As expected, results showed consistent patterns, suggesting that the effect can be generalized over a variety of institutions. The details of such analyses can be found in S4 Table in S1 File. Given that estimates of indirect effects were similar across the four institutions (b range = 0.007–0.011), we limit the report to trust in the police, as it will be the focus of Study 3. Overall, the relationship between trust in the police and interpersonal trust was mediated by feelings of security, b = 0.007; 95% CI [0.0068; 0.0087], even controlling for individual differences b = 0.008; 95% CI [0.0076; 0.0091], and differences in the quality of institutions, b = 0.008, 95% [0.0069; 0.0084].

As an additional robustness check, we also tested our hypotheses with a different model specification. We included countries as fixed effects, thus removing the multilevel structure. The results (using both aggregate measure of institutional trust and trust in the four different institutions) were in line with those presented above, even controlling for individual differences (see S5 Table in S1 File).

Discussion

The results of Study 2 replicated findings of Study 1, using cross-national data with representative samples. Taking together responses obtained from participants of 16 different countries, we found that individuals who trusted institutions tended to feel more secure, which resulted in higher levels of interpersonal trust. Remarkably, these effects have been observed even considering more general feelings of security, not directly tied to the specific institutions as in Study 1. Moreover, by including country-level indicators of institutional performance (both political and economic), we found support for the hypothesis that the indirect effect of the feelings of security is related more to individuals’ perception of the public institutions, rather than their actual efficiency and performance.

Study 3

Study 1 and 2 provided support for the hypothesis that institutional trust is positively associated to interpersonal trust, and that the effect is related to the feelings of security that institutions convey. In Study 3, we aimed to experimentally test this mechanism by manipulating institutional trust, in order to replicate the results obtained in Study 1 and 2. The manipulation consisted in providing participants with specific information about the institution’s competence, benevolence, and reliability, in order to elicit consequent trust assessments. Additionally, we wanted to extend our claims on trusting beliefs to actual trusting behavior in an economic game. Thus, we tested our main prediction that institutional trust promotes trusting behavior, operationalized by investments in a trust game with a stranger, by increasing feelings of security conveyed by institutions.

Moreover, we also tested an alternative mechanism, to disentangle a possible explanation that the effect of institutions merely depends on the expectations regarding the behavior of the interaction partner. This would allow to test the hypothesis that interpersonal trust is influenced by feelings of security rather than a change in normative expectations brought about by formal institutions.

Materials and methods

Participants

A total of 94 participants (70.2% female; Mage = 25.45, SDage = 6.24) were recruited from an online panel (i.e., Sona System) at a large Austrian University and received a 2 € show-up fee and a behavior-depending remuneration. Most had a high school diploma (44.7%) and reported a moderately left-wing political orientation (M = 4.12, SD = 1.57). Participants were mainly Austrians (59.5%), 22.3% were Germans, and the remaining 18.1% were German-speakers from other countries. Sensitivity analysis revealed that this sample size would result in 80% statistical power to detect a medium effect of institutional trust on trusting behavior (d = 0.58; [71]).

Procedure

Participants were invited to take part in an incentivized online study on decision-making. They learned that their choices could be matched with those of other anonymous participants from ten different countries, whose identity or belonging country would not be disclosed at any time. This matching protocol was introduced to manipulate institutional trust, providing the respondents with different information about the police in the partner’s home country. After the manipulation, we measured participants’ trusting beliefs toward the partner, trusting behavior, and expectations of reciprocity. Then, they completed a questionnaire assessing the feelings of security enhanced by the police depicted in the scenario, trust propensity, security values, risk attitudes, and political orientation.

Experimental manipulation (institutional trust)

Past research found that individuals lacking perfect information about others (e.g., in interactions with strangers) make inferences about others’ trustworthiness based on behavior of public officials in that society [53]. Following the same approach, at the beginning of the study, participants were randomly assigned to one of the two experimental conditions manipulating institutional trust (low vs. high) and were exposed to two scenarios providing different information about the police in the trustee’s home country (referred to as Country X from now on), that was never disclosed across the entire duration of the study. They read a fictitious report of a survey about police’s performance and perception in Country X the previous year. Following the definition of institutional trust as perception of benevolence, competence, and reliability of public institutions toward citizens (e.g., [37]), in the low institutional trust condition, the police were depicted as poorly qualified, neither fulfilling their obligations and nor serving the collective interest. Conversely, in the high institutional trust condition, the police were described as extremely skilled, committed, and responsible (see S3 Appendix in S1 File).

Manipulation checks

Two measures were used as manipulation checks to evaluate the extent to which the scenario elicited different degrees of (low vs. high) trust in the police. First, we directly asked participants how much would they trust the police in Country X on a seven-point Likert scale from 1 (not at all) to 7 (completely). Additionally, participants were asked to guess the trustee’s country out of a list of ten countries, select as those ranking highest (i.e., Switzerland, Luxembourg, Norway, Sweden, Finland) and lowest (i.e., Portugal, Slovenia, Hungary, Czech Republic, Greece) in institutional trust scores according to data from OECD [80]. We expected that participants exposed to the high institutional trust condition would have associated Country X to an actual country renowned for its institutional trust.

Dependent variables (trusting beliefs and behavior) and mediating variables (feelings of security and expectations of reciprocity)

In this study, interpersonal trust was operationalized as trusting beliefs and trusting behavior (i.e., the money invested in a trust game played with an unknown other) [81]. Participants were endowed with 5 Lab Coins (LC), each worth € 0.30, and assigned to the role of trustor. At stage one of the game, the trustor could transfer any of this amount (0–5 LC) to the trustee, keeping the remaining for herself, being aware that the transferred amount would have been tripled by the experimenter while passing it to the trustee. In stage two, the trustee could have transferred any portion of the tripled amount received back to the trustor. Importantly, they were informed that their decision would be randomly matched with that of another participant in the pool who will play a complementary role at a later stage of data collection in order to determine the final payment from the game. In reality, all participants played the sole role of trustor, since we were only interested in trusting behavior. The use of deception in this study (i.e., providing participants with fictitious information about the institutions in place in the trustee’s country) was functional to increase internal validity of the study and to set up a situation in which any observed effect on interpersonal trust would have been solely attributed to the manipulated information. Given that we did not assess actual return behavior, the final payment for the participants was determined by tripling the amount they transferred in the game (€ 0–1.50) and was paid in addition to the show-up fee. After verifying the comprehension of the game, we assessed expectation of reciprocity by asking to express the percentage of the money they expected to receive back (0–100). Then, as in Study 1, we measured trusting beliefs toward the trustee through an adaptation of General Trust Scale ([25], α = .88) and feelings of security using the 3-items measure (α = .96).

Control variables

To adjust for potential underlying baseline individual dispositions across the different conditions, a number of variables were included in the experimental design and analyzed as covariates in the mediational models. As Study 1, we included as covariates a measure of trust propensity ([74]; α = .75), security values ([75]; α = .72), and political orientation measured through a bipolar 10-point scale item. In addition, we included a measure of risk attitudes as further control, as trusting behavior consisted in an actual monetary investment decision, which is generally associated with individual risk preferences [82]. Risk attitudes were measured using the financial subscale of the Risk-Behavior Scale [83]. Here respondents are asked to indicate the likelihood to engage in a series of economically risky behaviors (10 items; e.g., “Spending money impulsively without thinking about the consequences”, α = .68) on a seven-point Likert answering scale ranging from 1 (extremely unlikely) to 7 (extremely likely). To avoid sequence effects, all items were presented in a randomized order within each scale.

Results

As expected, participants exposed to the scenario of high institutional trust reported more trust in the police of Country X (M = 5.15, SD = 1.07), compared to the other condition (M = 2.43, SD = 1.44), t(92) = -10.39, p < .001, d = 2.14. Also, a Chi-square test was performed to test whether, consistently with the experimental condition, participants associated the description of Country X to an actual high trust vs. low trust country as classified in OECD official rankings. As predicted, those in the high institutional trust condition associated Country X to a high trusting country significantly more than in the other condition, χ2(1, N = 94) = 68.12, p < .001 (Table 3), suggesting that the manipulation was successful in eliciting the intended perception of partner’s country institutions and, thus, institutional trust.

Table 3. Guessed trustee’s country according to experimental condition.

 Institutional Trust Switzerland Luxembourg Norway Sweden Finland Portugal Slovenia Hungary Czech Republic Greece
Low 0 4.35% 2.17% 0 0 4.35% 6.52% 32.61% 21.74% 28.26%
High 22.92% 10.42% 18.75% 27.08% 12.50% 0 2.10% 2.10% 2.10% 2.10%

The main effect of institutional trust on interpersonal trust

To test whether institutional trust had a main effect on trusting beliefs and trusting behavior, we used an independent samples t test comparing the trusting beliefs about the trustee and trusting behavior (i.e., the amount of money invested in the trust game) observed in the two experimental conditions. On average, participants transferred 70.6% (SD = 26.7%) of their initial endowment to the trustee. Results of the t test showed no differences between the two experimental groups in either trusting beliefs toward the trustee, t(92) = -1.00, p = .317, R2 = .01, nor trusting behavior, t(92) = -1.00, p = .321, R2 = .01 (see S6 Table in S1 File).

The indirect effect of institutional trust on interpersonal trust via feelings of security

A serial mediation (Process model 6) on a bootstrap sample of 5,000 participants showed a significant effect of institutional trust on the money invested in the trust game, mediated by the feelings of security, which impacted trusting beliefs toward the partner in the trust game, b = 0.21, 95% CI [0.06; 0.54], R2 = .11. The full serial mediation model remained significant after controlling for trust propensity, security values, risk attitudes, political orientation, and education, b = 0.19, 95% CI [0.03; 0.54], R2 = .13. Results of the mediations are presented in detail in Table 4.

Table 4. Results of serial mediation models for the effect of institutional trust (manipulation) on interpersonal trust through feelings of security.
Predictor and effect Outcome: trusting behavior
Model 1 Model 2
b SE 95% CI b SE 95% CI
Mediator 1: Feelings of security* -0.07 0.10 -0.28; 0.13 -0.07 0.11 -0.28; 0.15
Mediator 2: Trusting beliefs* 0.52 0.17 0.19; 0.85 0.51 0.18 0.15; 0.88
Institutional trust (Manipulation)    
Total effect 0.28 0.28 -0.27; 0.82 0.38 0.29 -0.19; 0.95
Direct effect 0.34 0.34 -0.34; 1.02 0.36 0.37 -0.36; 1.09
Indirect effect 0.21 0.11 0.06; 0.54 0.19 0.12 0.03; 0.54

Results based on 94 observations. Model 1: Mediation analyses did not include control variables. Model 2: Mediation analyses included trust propensity, security values, political orientation, risk attitudes, and education as control variables.

*Estimates of regressions of the mediators (feelings of security and trusting beliefs, respectively) predicting trusting behavior.

Testing two competing psychological explanations for enhanced interpersonal trust

One additional intended contribution of Study 3 was to test whether the indirect effect of institutional trust on interpersonal trust could simply be explained by increased expectations of reciprocity rather than increased feelings of security. To examine this possibility, we conducted a parallel mediation analysis (Process model 4) with 5,000 bootstrapped samples. The results show that feelings of security had a significant indirect effect on trusting beliefs toward the trustee, b = 0.41, 95% CI [0.13; 0.83], while expectations of reciprocity did not, b = 0.02, 95% CI [-0.01; 0.15] (all path coefficients are reported in S7 Table in S1 File).

Discussion

The results of Study 3 replicated the indirect effect obtained in Study 1 and 2 with experimental data. Institutional trust enhanced feelings of security, which in turn significantly predicted interpersonal trust. As expected, the extent to which participants transferred money to the other person depended on their achieved feelings of security from the institutions. Study 3 also generalized these effects on trusting behavior with real incentives, providing evidence for the external validity of the results.

Differently from Study 1 and 2, we did not observe a main effect of institutional trust on trusting beliefs or behavior. One possibility to explain these different findings can be attributable to the operationalization of institutional trust. In Study 3, institutional trust was indirectly manipulated by providing information about institutional performance, aimed at creating different perceptions of institutions in the two experimental condition. In the two surveys, however, respondents’ perceptions of institutions were built across years of repeated exposure to institutional performance and behavior of institutional representatives.

General discussion

Interpersonal trust among strangers is key for the societal, political, and economic development of a state. Given that interactions are embedded in a context regulated by societal institutions, recent research has increasingly focused on the questions whether and how these institutions can enhance (or impair) the development of interpersonal trust. In three studies, we tested the hypothesis that institutional trust indirectly promotes trust among strangers by increasing feelings of security, which in turn allow people to accept vulnerability and to trust others. Study 1 provided initial evidence for this underlying psychological process and showed that the association between institutional trust and interpersonal trust is mediated by feelings of security. Institutions that are trusted serve as a cue that individuals are protected, which in turn indirectly allows them to accept vulnerability and trust others. Study 2 further validated this initial evidence by analyzing cross-sectional data from 16 countries and using different operationalizations of the constructs. Finally, Study 3 provided an extension of the findings by manipulating institutional trust in an experimental design, and testing the effects on trusting behavior. In this study, we found again support for the indirect effect obtained in Study 1 and 2 with experimental data but, in contrast with these, we did not observe a main effect of institutional trust on trusting beliefs or behavior.

The current studies add an important piece to the puzzle on how micro-level perceptions and behaviors relate to macro-level societal processes. When it comes to institutional features, individual psychological processes often reflect the broader societal context. For example, individual self-regulation is higher in institutionally regulated countries [29], and citizens’ intrinsic honesty is affected by country-level norm violations [84]. With respect to trust among strangers, our findings suggest that trusted institutions can provide feelings of security that serve as a basis to develop interpersonal trust [42,44]. Given the vulnerability to exploitation that trusting acts involve [14], we traced back the effect of institutional trust to the key functions of institutions to serve the fundamental need to feel protected. Indeed, trusting institutions does not automatically lead individuals to feel secure. Even if institutions are considered competent and reliable, individuals still may feel highly insecure in unpredictable and extreme situation (e.g., terroristic attacks, that highly increase distrust toward others). This is confirmed by our results, showing that the two constructs are only moderately correlated (Pearson’s r = .50 and r = .18 in Study 1 and 2, respectively) and load on different factors.

Our findings are not in line with research that would propose that institutions have a detrimental effect on interpersonal trust in light of their primary role of providing assurance by affecting the incentive structure and individuals’ normative expectations [25,26]. In Study 2, we included a series of control variables related to institutional quality to control for the possibility that the actual performance of institutions is driving the effect. Among those, there were estimates of the ability of government to provide high quality public services, implement effective policies, protect legal entitlements, and to maintain social order through formal rules [85]. These variables did not affect the significance of the model. Moreover, when institutional trust was manipulated in Study 3, we observed an indirect effect on trusting behavior even if the institution was not directly involved in the interaction and had no actual power to influence the outcome of the interaction and provide assurance (e.g., by punishing exploitative actions). Also, this study sought to rule out that this effect could be merely explained by positive expectations about the partner’s behavior. Although this was not a key goal of the research, this finding suggests that social inferences are unlikely to be the main mechanism underlying the relationship between institutional and interpersonal trust [54]. If that would have been the case, we should have observed expectations to mediate this relationship, given that institutional representatives (the police in Study 3), according to this approach, should act as a signal of the type of game played in a certain society. Future research should further explore this question by designing ad hoc studies to understand the relative contribution of feelings of security and social inference-based mechanisms.

The current findings highlight the need to actually implement cues that generate trust in public institutions such as transparent communication, legitimate law enforcement, or explicit anti-corruption policies to promote trust in the general society and thereby, social and economic prosperity [46]. If public institutions cannot fulfil the need of individuals to feel secure, citizens may turn away from established institutions, start to individually protect themselves (e.g., by investing in lawyers and insurances), and support or develop new parallel institutions (e.g., alternative media) to achieve this need and restore trust levels. In extreme cases, as response to perceived insecurity, individuals might start to endorse nationalist positions [86], and even turn to anti-social organizations like the mafia in order to restore their lack of security [87,88]. Also, the results have implications for policy in light of research on the effects of individuals’ past experiences of victimization on interpersonal trust. In particular, trust has been showed to be hardly affected by direct victimization [89], but rather by a more general fear of crime, developed as response to the environmental context, such as segregated and disadvantaged neighborhoods [12,79]. This can undermine efficacy of interventions exclusively aimed at reducing victimization experiences (such as severe monitoring and sanctioning of violent and property crimes). Thus, public institutions might combine these interventions together with others with a focus on restoring feelings of security, such as the implementation of direct and accessible dialogue and transparent communication with citizens, as well as the possibility to monitor openly this process, especially in disadvantaged contexts where fear of victimization is more prevalent.

Limitations and future research

Our findings have some limitations that need to be acknowledged. Due to the use of observational data across Study 1 and 2, it may be argued that our results are affected by endogeneity. That said, we addressed this issue in two ways. First, in both Study 1 and 2 we included relevant control variables related to stable individual dispositions to prevent overestimating the hypothesized relationships, which are often overlooked in current research practices (see [39]). Second, we specifically integrated the survey evidence provided in Study 1 and 2 with an experiment that exogenously manipulated institutional trust by providing specific information about institutions in the trustee’s country (Study 3).

Another potential limitation is the lack of a main effect of institutional trust in Study 3, which was observed in Study 1 and 2. That said, this finding does not affect the overall conclusion we derive from the results for several reasons. First, the main focus of this work was testing the indirect effect of institutional trust on interpersonal trust and this effect was replicated across all studies (with different datasets and operationalizations), even when tested against competing mechanisms. Moreover, our manipulation in Study 3 was carefully designed from previous research which found a significant effect on trusting beliefs toward strangers based on the behavior of institutional representatives [53]. Therefore, it is possible that higher sample sizes would be successful in detecting a significant main effect. Although previous research found evidence that the presence of cues (or inferences), rather than the actual implementation of mechanisms (such as reputation), is enough to elicit an effect [90], future research might consider to identify the boundary conditions of this effect by designing a setting that more closely resembles daily experience with (not) trusted institutions, that could actually intervene in the situation (e.g., punishing untrustworthy behavior), and not involving the use of deception, in order to draw stronger conclusions about whether and how this perception, and subsequent feelings, affect interpersonal trust.

Moreover, even if we collected evidence from several countries, all respondents of the current studies were from Western democratic countries in which institutional trust levels are generally high. Additionally, two of the three studies involved convenience samples and, thus, not representative of the national population. Thus, a remaining question for the future would be to test these hypotheses on a more diverse set of institutional contexts and to test the generalizability in non-Western societies. Last, although exchanges with strangers within a society often do not exceed a single interaction, future research could explore the role of institutional trust in repeated interactions, where reputational information comes into play.

All things considered, the present findings appear robust and generalizable across research methodologies and variables operationalizations, and remain consistent even when controlling for relevant individual characteristics and institutional performance indicators. Study 1 allows to generalize the results across the entire set of studies by firstly testing the reliability of the three-items measure of feelings of security and trusting beliefs then adopted in Study 3, and to provide a more fine-grained measure of institutional trust as compared to the standard single-item questions adopted by the ESS in Study 2. Additionally, by testing our hypotheses across different conceptualizations of strangers (i.e., fellow citizens, most people, a person from a foreign country), the current set of studies controlled for the risk of refer to different targets, ranging from family members to people from other nationalities, while answering to the standard interpersonal trust question that is widely diffused in survey research (i.e., trust radius problem; [91]).

Concluding remarks

Trusting strangers is a fundamental pillar of human societies. Understanding how institutional trust can shape and maintain interpersonal trust, with a focus on individual’s needs, brings together converging insights from different research traditions and methodologies. The present work provides survey, cross-cultural, and experimental evidence in support of the conclusion that trust in formal institutions is important for understanding variation in interpersonal trust, especially when they manage to enhance a feeling of security among citizens. This is relevant both for the theoretical debate around interpersonal trust and social capital. But also, the role of institutions may become even more essential, as societies become more and more complex, and if anything, move away from small societies in which trust is largely based on tight groups who meet face-to-face in their community, the workplace, or the local café.

Supporting information

S1 File

(DOCX)

S1 Data

(SAV)

S2 Data

(SAV)

Data Availability

All relevant data are within the manuscript and its Supporting Information files.

Funding Statement

The research was supported by the Austrian Science Fund (FWF; project 24863-G1) awarded to KG. The funding source contributed to proofreading of an earlier version of the manuscript.

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Decision Letter 0

Valerio Capraro

8 Apr 2020

PONE-D-20-07477

Enhancing feelings of security: How trustworthy institutions promote interpersonal trust

PLOS ONE

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Additional Editor Comments (if provided):

I have now collected three reviews from three experts in the field. The reviewers are somehow split. One is very critical and suggests rejection. The other two are less critical, one suggests minor revision and the other one suggests major revision. After reading the manuscript myself, I have opted for following the majority and invite you to revise your work according to the reviewers' comments. Needless to say that all comments must be addressed to the best of your possibilities, including, and especially, those from the "negative" reviewer.

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And I take this occasion to wish you and your loved ones to be safe and healthy during these difficult times.

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Reviewers' comments:

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Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: Yes

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Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: Yes

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5. Review Comments to the Author

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Reviewer #1: Thank you for the opportunity to review this piece. The authors take up a very interesting question regarding the oft-identified relation of trust in institutions and trust in individuals. As the authors rightly note, the question is a much contested one both in the direction of the effect and in its mechanism. The paper here purports to wade into this debate but fails to contribute for two major reasons.

1- Studies 1 and 2 add little new to this discussion (as the authors note, these are replications) but most concerningly, they are imprecise in measurement. The paper suggests that it takes Mayer and Rousseau's definitions of trust as their starting point but instead measure institutional trustworthiness. That measure of trustworthiness is then averaged across several institutions to create a poorly theorized amalgamation of trust in "institutions" with no attention to whether the individual has any real information about them. These are then connected with generalized trust in others which were also argued to be an important control variable that was missed in previous research. Thus, the DV, IV, and control for these studies all measure generalized trust or trustworthiness of a variety of targets in a way that makes them all just slightly different measures of trust propensity. As a result, the relations among them look like endogenity issues and little conceptual or empirical defense is offered to the contrary.

2- Study 3 seeks to identify a single institution and test the effect of changes in its trustworthiness on trust in a specific other. This helps a lot with the clarity lacking in S1 and S2 but S3 fails to find a significant direct effect of institutional trust on interpersonal. Nonetheless, the authors go on to test a mediation which does make me wonder if I missed something but the paragraph in the middle of page 26 pretty clearly states that "no differences emerged for either trusting beliefs... nor trusting behavior". Indeed, this makes a great deal of sense as I can't really see why hearing about the police in a random trust game partner's country would impact my thoughts about their behavior in the game. Nothing they are doing (returning or not returning the funds) would be illegal and it's asking a lot to think that a college student would think through the stimulus enough to believe that a truly effective police force would create a society in which people be more likely to return more money in a computer mediated trust game played as a way to get course credit. Without this direct effect, the rest of this study doesn't make a whole lot of sense to me.

Smaller concerns:

--I would encourage the authors to be a bit more careful in conceptualizing their constructs. Often the manuscript uses the terms trust, trustworthiness, or trusting behavior as interchangeable. I understand the strong empirical relations among the variables but this literature has progressed to a point where it's not hard to keep them separate. Indeed, the Mayer Davis and Schoorman article that was cited here is a major touch point for this clarity.

--I am a little concerned about the S1 and S3 samples' representativeness. Social media ads are often displayed according to algorithms and college student samples are notoriously non-generalizable, especially when thinking across cultures as this study wants to do. It may be that there is little to be concerned about here given the samples that were actually collected but more was needed to show that relations identified here could reasonably generalize.

--I would note that what has been randomly manipulated in this study is not, in fact, trustworthiness or trust, but instead information that is intended to impact those assessments. Manipulation checks help here as they can show whether--all else being equal (or at least randomly distributed)--trust assessments change as a result of the information presented. The first manipulation asks not about trust but likelihood of trusting (which may just be a translation issue) but the second has nothing to do with trust at all. Clearer defense of how the information that was randomly presented actually gets at the intended IV would be welcomed.

--I am pretty sure that PLoS ONE allows for in-text tables and figures. Relegating most of them to the appendix seems less than ideal.

Reviewer #2: [See attachment to visualize the review correctly]

This is, potentially, an interesting contribution to the literature on institutional and social trust. However, the manuscript has several issues and requires major revisions to be publishable. Here are some suggestions to improve the paper:

General

1. The authors argue that the relationship between social and political trust has been neglected in the literature (e.g. in the conclusions: “Decades of research have focused on several processes that may promote trust among strangers, but very little attention has been devoted on one recurrent feature that characterize modern human interactions: the presence of institutions”). However, as the authors acknowledge in their literature review, there is a relevant body of research investigating precisely this relationship following different approaches: Sonderskov, Brehm & Rahn, Lekti, Rothstein, Uslaner, Stolle have addressed this topic (all mentioned in the manuscript). I would suggest to add the following references as well:

Herreros F, Criado H. The state and the development of social trust. International Political Science Review. 2008;29(1):53–71

Lo Iacono S. (2019). Law-breaking, fairness, and generalized trust: The mediating role of trust in institutions. PloS one, 14(8).

Richey S. The impact of corruption on social trust. American Politics Research. 2010;38(4):676–90.

Js You. Social trust: Fairness matters more than homogeneity. Political Psychology. 2012;33(5):701–21.

I invite the authors to acknowledge previous research on institutional trust/institutions and social trust throughout the entire manuscript (in line with their literature review), while fleshing out more clearly the main contribution of the manuscript, namely the analysis of the mediation effect and the disentangling of the psychological processes behind the relationship (which, indeed, has not been empirically investigated, though theoretically argued to some extent – e.g. Rothstein and Stolle 2008).

2. The methods and results sections need extensive revising for all three studies. Given the wide variety of measures employed, it is often unclear how concepts are operationalized. A descriptive table showing the coding, the mean, SD, N of the variables used in each study would be extremely helpful (maybe you can include this in the SI). Also, it would be good to present results from the mediation models in a table (one for each study), showing the effects with and without covariates (in the SI you could report the complete tables with all coefficients). Side note: at p. 15 the authors mention that “the lack of control for individual differences in previous cross-sectional studies might have overestimated the relationship

between the two forms of trust in the past”. Looking at previous studies in the literature (see point 1), this is hardly correct (they do employ a wide variety of controls at the individual level). Also, while using controls in Studies 1 and 2 makes perfect sense because they are observational studies, Study 3 is an experiment and it shouldn’t require controls if the randomization worked properly. Including controls for Study 3 should be justified by arguing that you are adjusting for (potential) differences in baseline covariates across the different conditions.

3. There is no explanation or description of the pilot in the main text – the authors briefly mentioned it in the literature review at p. 11: “Thus, for a better understanding of the relation between institutions and interpersonal trust, in the next section, we will focus on research addressing the effect of institutional trust on interpersonal trust. In S1 Appendix we report the results of an additional experimental pilot study that manipulated the presence vs. absence of institutions, and provided evidence for its cascading effects on institutional trust, trusting beliefs, and trusting behavioral intentions towards a stranger”. I would suggest the authors to provide a more detailed justification of the pilot in the general description of their work.

4. The manuscript requires a careful revision of the text. Sometimes sentences appear quite disconnected, or are simply inconsistent with the rest of the paragraph. I report here a couple of cases, but an accurate double-check is required. Examples, p.15: “The whole research was conducted in accordance with the Declaration of Helsinki (7th revision, 2013) and local ethical guidelines for experimentation with human participants and was approved by the institutional review board at the University of Turin and by the ethical commission of the Zeppelin University in Friedrichshafen. All subjects gave written informed consent prior to the experiment. To avoid sequence effects, in Studies 1 and 3 all items were presented in a randomized order within each scale and, unless otherwise stated, they were answered on a seven-point Likert scale from 1 (I do not agree) to 7 (I totally agree)”.

At p. 17 (while describing Study 1): “From these items, we created a general aggregated measure of institutional trust by averaging scores of these five scales. As in Study 1, trusting beliefs toward Italian

citizens were measured through the adapted General Trust Scale ([23], α = .93)”.

5. In the manuscript, the authors often discuss the direct impact of institutional trust on interpersonal trust. Fig. 1, however, does not represent this accurately (as it shows only an effect on trusting behavior). Thus, I would suggest to modify Fig.1 and make it more consistent with the authors’ general argument/interpretation of results. Here is a possible “solution” (apologies for the sketchy picture):

[Fig.1 modified - see attachment]

Study 1

The contribution of Study 1 is difficult to grasp at the moment. Indeed, since it does not employ a representative sample of the population and there is no manipulation (not sure if it makes sense to report the results of the sensitivity analysis at p.16), Study 1 appears to contribute very little to the discussion, especially in comparison to Studies 2 and 3. I suggest to move Study 1 to the SI to give more space to Studies 2 and 3, which require more information. If the authors disagree with this comment, I believe they should better justify the value/input of Study 1 (i.e. how does this study exactly improve on our current knowledge of this relationship?). The following passage at p. 20 provides a good hint on where to start (from my point of view): “This different operationalization of interpersonal trust would allow to relate our findings to previous evidence from survey studies using this scale (e.g., [36]) and to generalize them above specific trust targets (i.e., members of own community such as Italian citizens in Study 1)”.

Study 2

1. Given that the mediation mechanism does not involve level 2 (i.e. country-level) variables and they are not interested in exploring the impact of any country-level variables on trust, I don’t see why the authors use multilevel mediation. Instead, they could simply control for all country differences (i.e. having countries as a fixed-effect, as they do for survey-years). This should tell us whether the mediation effect is working across countries, which would be more relevant/interesting for their analysis. If the mediation effect is not working once they control for countries, then it might be interesting to understand why this is the case/for which countries the mediation works/what country-level factors are important in this respect (re-introducing the multi-level mediation here).

2. Considering that in Study 3 the authors are manipulating trust towards the police (rather than the broader concept of institutional trust), it would be good to have a separate part of the analysis focusing on the same aspect in Study 2 (trust in the police � feelings of security � generalized trust). This would also help the reader to see more clearly the link between the two studies.

3. As mentioned in the general comments section, I believe that Study 2 needs a table where you concisely present the results from the mediation model (i.e. the different paths for direct and indirect effects) with and without covariates (e.g. Model 1 no controls, Model 2 controls at the individual level, Model 3 controls for countries and survey-years).

Study 3

1. Study 3 requires a more detailed presentation of the design (e.g. how many sessions did you have? How many people per session? It would be good to have more details on the trust game – one-shot? Strategy method? How much could the trusters send? What was the multiplier? Etc.). At the moment, it is difficult to understand what the subjects exactly experienced and in which order (e.g. did they play the trust game after the questions on trusting beliefs? Did the questions on expectations of reciprocity followed the trust game?). This is important to properly evaluate the results of the study.

2. The type of behavioural trust you are measuring here is quite different from the one measured in Studies 1 and 2. Indeed, here subjects are asked whether they would trust someone from another country (i.e. Country X – trustee’s home country. Side note: it would be good to know why you had those 11 countries, on which basis you selected them etc.). This is not equivalent to measuring trust towards unknown fellow citizens/strangers, as the form of trust measured in Study 3 involves a stronger out-group component (it should be closer to trust towards migrants). The theoretical framework of Study 3 should discuss this issue and interpret findings accordingly.

3. In my view, deception could have been avoided (by designing the experiment more carefully). I would invite the authors to justify their decision, explaining why deception was needed in this case.

4. Recoding of trusting behavior in Table S4 does not seem consistent with results presented at p.26: “On average, participants transferred 70.6% (SD = 26.7%) of their initial endowment to the trustee, […] (see S4 Table)”. While in table S4 you report the following:

[See attachment]

Institutional Trust

Low High

M (SD) M (SD)

Trusting behavior 3.39 (1.39) 3.67(1.28)

How should we interpret the values 3.39 or 3.67 in relation to the value of 70.6%? As mentioned in the general comments, the coding of variables is quite confusing, and it appears to be inconsistent in some passages. Please double-check carefully the manuscript in this respect.

5. Table 2 was cut and didn’t properly show the results.

6. I would like to invite the authors to elaborate more on the mediation effect reported in Study 3. Indeed, while there is no significant direct effect from the manipulation of trust (towards the police) to trusting behaviors, the analysis suggests that there is a significant indirect effect (through feelings of insecurity). Is this a case of indirect-only mediation (e.g. Zhao, X., Lynch Jr, J. G., & Chen, Q. 2010. Reconsidering Baron and Kenny: Myths and truths about mediation analysis.)? Or is it actually due to a moderating effect? Also, how is this consistent with results reported in Study 2 where, in my understanding, we have both significant direct and indirect effects? How do the authors explain this difference? How should we interpret findings from Studies 2 and 3 once taken together?

Reviewer #3: 1) I think the paper could cite the existing and quite large literature in economics on the relationship between institutions and trust, in particular the work by Luigi Guiso and Guido Tabellini.

2) I am not sure about the value added of Study 1. Study 2 also uses observational data and therefore suffers from the same problem as Study 1, but is superior and more powerful given the larger number of observations and the different countries. In my view, Study 2 makes Study 1 redundant. If the authors decide on keeping Study 1, I encourage them to point out more clearly the differences to Study 2, and in particular what we learn from Study 1 that we do not learn from Study 2.

3) Statistical Analysis: Overall, the statistical analysis is conducted appropriately, but I have some questions:

- Do you include country or subnational region fixed effects in Study 2? They would absorb many fixed institutional and economic characteristics of a country or region that could affect institutional trust and trust in strangers.

- For the reader it would be interesting to know for each study what is the percentage of the effect of total effect of institutional trust on trust that is mediated by safety considerations.

- The t-test you mention is not clear to me ("On average, participants transferred 70.6% (SD = 26.7%) of their initial endowment to the trustee, and no differences emerged for either trusting beliefs... " Do you test the difference in money transferred between the two experimental groups? What is the result?

4) Presentation of results:

- I find the tables not easy readable and not very intuitive. For example, variable names are not intuitive, number of observations are missing, and it is not clear from the table what are the control variables included in the regressions.

- There is no Table with results for Study 2.

- Table 2 that contains the results for Study 3 is too large and half of it is not readable.

**********

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Attachment

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PLoS One. 2020 Sep 11;15(9):e0237934. doi: 10.1371/journal.pone.0237934.r002

Author response to Decision Letter 0


5 Jun 2020

Dear Dr. Valerio Capraro,

Enclosed is a revised version of our manuscript “Enhancing feelings of security: How trustworthy institutions promote interpersonal trust” which we submitted for publication in PLOS ONE (Manuscript PONE-D-20-07477). We were grateful to receive three extremely constructive reviews, each of which expressed enthusiasm about the potential of the paper, as well as constructive criticism and comments for improving the paper.

We greatly appreciate your and the reviewers’ constructive comments on our previous manuscript. We have thoroughly considered (and sometimes discussed) each of these suggestions and used them to strengthen the manuscript. Below we respond in detail to each of your own and the reviewers’ comments. For an easier navigation of the manuscript, our responses are listed in italics, and when changes have been made to the manuscript, we insert a section of text from the paper and/or provide the page numbers of the tracked version of the revised manuscript where the revisions can be found. We hope you find this structure easy to navigate. Thanks again for this opportunity and we look forward to hearing about your decision.

Reviewer #1

Thank you for the opportunity to review this piece. The authors take up a very interesting question regarding the oft-identified relation of trust in institutions and trust in individuals. As the authors rightly note, the question is a much contested one both in the direction of the effect and in its mechanism. The paper here purports to wade into this debate but fails to contribute for two major reasons.

1- Studies 1 and 2 add little new to this discussion (as the authors note, these are replications) but most concerningly, they are imprecise in measurement.

Thank you for raising the concern about the magnitude of the contribution of Study 1 and 2 to the current debate. Although part of the research questions has been addressed in the past, in our view (see below) is that our set of studies contribute new insights to the literature. But your comment helped us realize that we did not adequately discuss or illustrate the novelty of our findings in the previous version of the manuscript (as Reviewers 2 and 3 pointed out as well).

The main contribution of both studies is to test the mediational role of feelings of security, an underlying mechanism that has been suggested as potentially relevant in previous research (e.g., Robbins, 2011; Rothstein & Stolle, 2008) but that has never been empirically tested. We revised the introduction section (p. 7) and the introduction to Study 1 (p. 9) to make this contribution more explicit. Moreover, although the relation between institutional and interpersonal trust has been already investigated, we believe that being able to replicate previous research provided us a solid base on which then we could confidently add incremental insights about the underlying psychological mechanism. This seems especially important in times when replicability of research in psychology is a serious issue and often discussed within and beyond the boundaries of the scientific literature.

We also made sure to enhance clarity and precision of all aspects regarding definition, measurement, and operationalization of the key constructs in the new version of the manuscript.

Please see below our responses regarding your measurement concern.

The paper suggests that it takes Mayer and Rousseau's definitions of trust as their starting point but instead measure institutional trustworthiness.

Thank you for this point. This gives us a chance to clarify our choices in terms of measurement and how they relate to the literature. The focus of this research is on the interplay of trust in institutions and trust in strangers. We cite pioneering work by Mayer et al. (1995) and Rousseau et al. (1998) in defining interpersonal trust, our outcome variable as “a psychological state that involves the intention to accept vulnerability in social interactions, under conditions of social risk and interdependence” (p. 2), as trust toward strangers involves the highest risk and uncertainty.

However, it is important to note that the definition of institutional trust (our predictor variable in the model) is rooted in a different (interdisciplinary) literature. Specifically, institutional trust is defined as “the extent to which individuals accept and perceive institutions as benevolent, competent, reliable, and responsible toward citizens” (p. 5). The measures used to operationalize institutional trust reflects this individual perception in Study 1 (e.g., “I trust the police in Italy because they behave benevolently toward citizens”) and Study 2 (e.g., “How much do you personally trust each of the following institutions”), respectively. We edited and re-structured the method section of all studies to provide more clarity. Throughout the manuscript, we double-checked all terms we used to ensure to use always exactly the same wording instead of variations. Thanks to your comment, our terminology became more stringent now.

That measure of trustworthiness is then averaged across several institutions to create a poorly theorized amalgamation of trust in "institutions" with no attention to whether the individual has any real information about them.

Our approach in selecting multiple different institutions had the aim to gain insights on the generalizability of our assumption, thus was guided by our research question, and the aggregation of institutional trust assessments across a range of institutions is a common practice adopted in previous research in institutional trust (e.g., Irwin, 2009; Nannestad et al., 2014; Seifert, 2018; Zmerli & Newton, 2008).

As we describe in the introduction, we assumed that feelings of security being mostly conveyed by public institutions that deal with law and order (p. 6-7), but previous literature suggests that a broad range of institutions might fulfill this function (e.g., Mayseless & Popper, 2007) as long as they convey a sense of protection. Accordingly, we did not limit our investigation to one particular institution and, indeed, our findings support the generalizability of this effect across different institutions.

That said, we see the benefit of not exclusively performing the analyses at the aggregated level. For this reason, together with models using the aggregated index of institutional trust as a predictor, we now report the results of a series of additional analyses (with and without control variables) using the single institutions in Study 1 (Table 1) and Study 2 (S4 Table and S5 Table). Overall, all analyses remained significant when trust in a single institution was considered as predictor (the only exception was for the indirect effect of religious institutions, which became non-significant after controlling for individual differences, which is discussed at p. 14).

As to your point about making sure that individuals have any real information about institutions, in Study 1 our approach to making sure that all respondents had information about the institutions of the country was to only select respondents with at least 18 years of age and with Italian nationality, which are the prerequisites to exercise voting rights in Italy. We now report this in the text (p. 10).

These are then connected with generalized trust in others which were also argued to be an important control variable that was missed in previous research. Thus, the DV, IV, and control for these studies all measure generalized trust or trustworthiness of a variety of targets in a way that makes them all just slightly different measures of trust propensity. As a result, the relations among them look like endogenity issues and little conceptual or empirical defense is offered to the contrary.

Our main goal is to understand the relation between institutional trust and how this can affect trust toward strangers. We agree that these different forms of trust may be potentially explained by an underlying propensity to trust others (defined by Mayer et al. as “a stable within-party factor that will affect the likelihood the party will trust. [...]. Propensity will influence how much trust one has for a trustee prior to data on that particular party being available”, p. 715). This is the reason why we considered it important to include a measure of trust propensity in Studies 1 and 3. This measure is an often-used as general form of readiness to trust, aimed to capture differences in general trust between people, rather than differences in trust among specific partners; such partner-specificity is therefore not included in the measurement. In our view, it is reassuring that we find support for our hypotheses whether or not we control for individual differences in trust propensity.

The inclusion of a trait variable that can account for the variation in the outcome is a common practice, and has been applied also in the trust field. For example, the same theoretical model of Mayer and colleagues include both trust and trust propensity, and previous research tested hypotheses accounting for multiple types of trust in the same model (e.g., institutional trust, trust propensity, and trusting beliefs in Moin et al., 2015). We hope that with the current revision we clarified this even further.

Regarding possible endogeneity in the model, we believe that combining observational evidence (Study 1 and 2) with experimental (Study 3) provides compelling evidence about the robustness of the hypothesized relations. In particular, we designed Study 3 with the explicit goal to implement an exogenous manipulation of institutional trust and found evidence for the proposed indirect effect (i.e., institutional trust impacting trust in others via feelings of security). This evidence, along with past research that has disentangled the directionality of the relation between trust in institutions and trust in others, provide evidence in support of the convergent validity of the present findings. We specifically discuss this aspect in the “Limitations and future research” section of the revised version (p. 30).

2- Study 3 seeks to identify a single institution and test the effect of changes in its trustworthiness on trust in a specific other. This helps a lot with the clarity lacking in S1 and S2 but S3 fails to find a significant direct effect of institutional trust on interpersonal. Nonetheless, the authors go on to test a mediation which does make me wonder if I missed something but the paragraph in the middle of page 26 pretty clearly states that "no differences emerged for either trusting beliefs... nor trusting behavior".

Indeed, this makes a great deal of sense as I can't really see why hearing about the police in a random trust game partner's country would impact my thoughts about their behavior in the game. Nothing they are doing (returning or not returning the funds) would be illegal and it's asking a lot to think that a college student would think through the stimulus enough to believe that a truly effective police force would create a society in which people be more likely to return more money in a computer mediated trust game played as a way to get course credit. Without this direct effect, the rest of this study doesn't make a whole lot of sense to me.

Thanks for this point. You are correct in pointing out that the results did not reveal a main effect of our manipulation on interpersonal trust (operationalized as both trusting beliefs and behavior).

First of all, in our model we predicted both a main and an indirect effect (see opening of “The current studies” p. 8). Even if we did not find a main effect, we find a significant indirect effect via feelings of security and trusting beliefs. To do so, we performed a path analysis in light of the large consensus that the lack of a main effect should not be considered as a necessary prerequisite to perform such a test, especially when the relationships among the variables are theoretically guided (Shrout & Bolger, 2002; Zhao et al., 2010). Moreover, we tested this path model against a competing model and found no support for the latter.

That said, we completely agree with you that this only provides support for part of our hypotheses and that we should discuss the lack of main effect. Following your comment, we also revised the manuscript to relate findings of Study 3 to those obtained in Studies 1 and 2 and provided possible explanations for the observed lack of main effect (p. 26-27, p. 30).

For example, regarding your point on the manipulation, we think that our rationale is justified for two main reasons. First, we designed our manipulation to affect interpersonal trust in light of what has been proposed by Rothstein & Eek (2009). That is, individuals lacking perfect information about others (e.g., in interactions with strangers) make inferences about others’ trustworthiness based on behavior of public officials in that society. This guided our choice of the manipulation (i.e., providing information about performance of the police). In the current version, we clarify the rationale of the manipulation (p. 22).

Second, we have reasons to believe that even if we did not implement such a setting in which institution could directly regulate the social exchange, the current design of Study 3 is suitable to test our hypotheses about interpersonal trust. Research in psychology has found that mere cues of reputation, or group membership can have an effect on behavior even in one-shot interactions (Romano et al., 2017; Yamagishi & Mifune, 2008), where no actual future consequences should not matter (as they would in repeated interactions). We revised the introduction (p. 4-5) to make clear that our predictor variable is not related to actual performance of institutions (such as in Herreros & Criado, 2008; Lo Iacono, 2019)

As to the reason why we did not observe such effect in place, there are two potential possibilities that we now discuss in the General Discussion section. First, it is true that in our manipulation of information about police in partner’s country the institution does not have a direct link to the game (i.e., there are no formal rules or laws broken in the trust game and, even if, the police cannot actually intervene to regulate the social exchange). This might be a reason why we did not observe a main effect. Testing these hypotheses in an experimental setting that more closely resembles daily experience with trustworthy – or untrustworthy – institutions, that could actually intervene in the situation (e.g., punishing untrustworthy behavior) is an interesting direction for future research, which we now discuss at page 30-31. Another possibility is that people just learned about the institution and were asked a one-shot interaction. Future research may also address this aspect, by investigating whether the effect would emerge in repeated interactions (with both institution and the partner).

As a minor note, following your comment about the “computer mediated trust game played as a way to get course credit”, we disambiguated the description of the incentive structure in the text to clarify that decisions were economically incentivized (both as show-up fee and behavior-dependent remuneration) and course credits were not at stake (p. 23).

Smaller concerns:

--I would encourage the authors to be a bit more careful in conceptualizing their constructs. Often the manuscript uses the terms trust, trustworthiness, or trusting behavior as interchangeable. I understand the strong empirical relations among the variables but this literature has progressed to a point where it's not hard to keep them separate. Indeed, the Mayer Davis and Schoorman article that was cited here is a major touch point for this clarity.

We realized that, indeed, in the previous version of the manuscript we used some inconsistent wording that could have caused some confusion. We removed all the inconsistencies and now only stick to institutional trust, trusting beliefs, trusting behavior, and trust propensity. Importantly, in light of these changes, we decided to edit the title of the paper, as the previous version mentioned “trustworthy institutions”. The original wording could have been a primary source of confusion as the focus of the research is institutional trust. Also, following the excellent suggestion of Reviewer 2, we created a new table (S1 Table) that summarizes the operationalization, definition, and descriptive statistics for each variable in the model. This overview should be helpful, as these measures are rooted in somewhat different literatures (even disciplines).

--I am a little concerned about the S1 and S3 samples' representativeness. Social media ads are often displayed according to algorithms and college student samples are notoriously non-generalizable, especially when thinking across cultures as this study wants to do.

This is a fair point. But allow us to clarify what we initially defined as “social media posting” in Study 1. The call for participation was not displayed as an advertisement (thus, was not affected by algorithms in targeting specific populations), but as a regular post coming from one of our social media accounts, that was shared with more users with a snowball sampling. We specify this in the text now (p. 10).

Moreover, please also note that Study 2 was a large-scale study including representative data from 16 countries, and yielded findings that were consistent with the other results. We believe that this alleviates this concern substantially.

It may be that there is little to be concerned about here given the samples that were actually collected but more was needed to show that relations identified here could reasonably generalize.

The samples used in Study 1 and 3 are not representative and resemble more the type of samples that are the norm in the psychological field. However, we also agree with the importance of generalizability and we tested our model on European Social Survey data which are nationally representative in Study 2, finding consisting results. In Study 1, we collected a sample that, although not representative, was distributed across the Italian regions (“The participants’ regions of origin were proportionally distributed among north (43.1%), center (14.9%), and south (42%) Italy”, p. 10). In Study 3, the sample is perfectly comparable to the sample examined in the original experiment of Rothstein & Eek (2009), and on which current experimental evidence is based.

Nevertheless, we now acknowledged the non-representativeness issue of Studies 1 and 3 in the limitation section and suggest it as next step in the future directions of this line of research (p. 31).

--I would note that what has been randomly manipulated in this study is not, in fact, trustworthiness or trust, but instead information that is intended to impact those assessments. Manipulation checks help here as they can show whether--all else being equal (or at least randomly distributed)--trust assessments change as a result of the information presented. The first manipulation asks not about trust but likelihood of trusting (which may just be a translation issue) but the second has nothing to do with trust at all. Clearer defense of how the information that was randomly presented actually gets at the intended IV would be welcomed.

Thank you for the remark. We integrated new content that better clarifies how information about institutions relates to institutional trust, so that our manipulation in Study 3 would become more straightforward (p. 4 in the introduction, p. 20 in Study 3, and p. 30-31 in the final discussion).

We believe that, once clarified that we are manipulating information intended to impact institutional trust, manipulation checks are adequate to assess whether we have been successful or not in eliciting such perceptions:

- For the first manipulation check, there might be a translation issue in place, as the original German wording was not intended to ask about “likelihood” of trusting (as hypothetical attitude, or as probability to trust). The response set should thus be interpreted as ranging from “to not at all trust” to “completely trust”. We disambiguated it and changed the text accordingly (p. 22).

- For the second manipulation check, we now provide more detail and rationale (p. 22). Also, we included the table showing the percentage of trustee’s countries guessed according to experimental condition (previously presented in the SI) in the main text for clarity (Table 3).

--I am pretty sure that PLoS ONE allows for in-text tables and figures. Relegating most of them to the appendix seems less than ideal.

In the updated version of the manuscript we revised the tables to include more information (Table 1 and 4) and included new tables (Table 2 and 3).

Reviewer #2

This is, potentially, an interesting contribution to the literature on institutional and social trust. However, the manuscript has several issues and requires major revisions to be publishable. Here are some suggestions to improve the paper:

General

1. The authors argue that the relationship between social and political trust has been neglected in the literature (e.g. in the conclusions: “Decades of research have focused on several processes that may promote trust among strangers, but very little attention has been devoted on one recurrent feature that characterize modern human interactions: the presence of institutions”). However, as the authors acknowledge in their literature review, there is a relevant body of research investigating precisely this relationship following different approaches: Sonderskov, Brehm & Rahn, Lekti, Rothstein, Uslaner, Stolle have addressed this topic (all mentioned in the manuscript). I would suggest to add the following references as well:

Herreros F, Criado H. The state and the development of social trust. International Political Science Review. 2008;29(1):53–71

Lo Iacono S. (2019). Law-breaking, fairness, and generalized trust: The mediating role of trust in institutions. PloS one, 14(8).

Richey S. The impact of corruption on social trust. American Politics Research. 2010;38(4):676–90.

Js You. Social trust: Fairness matters more than homogeneity. Political Psychology. 2012;33(5):701–21.

I invite the authors to acknowledge previous research on institutional trust/institutions and social trust throughout the entire manuscript (in line with their literature review), while fleshing out more clearly the main contribution of the manuscript, namely the analysis of the mediation effect and the disentangling of the psychological processes behind the relationship (which, indeed, has not been empirically investigated, though theoretically argued to some extent – e.g. Rothstein and Stolle 2008).

Thank you for this suggestion and this list of relevant readings. They now are acknowledged in the literature review and helped us to better structure the introduction, and highlight how the present studies can contribute to this line of research.

2. The methods and results sections need extensive revising for all three studies. Given the wide variety of measures employed, it is often unclear how concepts are operationalized. A descriptive table showing the coding, the mean, SD, N of the variables used in each study would be extremely helpful (maybe you can include this in the SI).

We re-structured the methods sections of all three studies and created different sub-sections in which the variables are described and presented in a consistent order. As suggested also by Reviewer 1, Study 3 went through the most extensive re-writing to clarify each aspect of the experimental procedure.

We also followed up on your suggestion and created a table that shows the variables used in each study (S1 Table) to test the model, together with their descriptive statistics information, a short definition and reference for each construct.

Also, it would be good to present results from the mediation models in a table (one for each study), showing the effects with and without covariates (in the SI you could report the complete tables with all coefficients).

Thanks for the suggestions, we have now included such tables (Table 1, 2, and 4) in the text.

Side note: at p. 15 the authors mention that “the lack of control for individual differences in previous cross-sectional studies might have overestimated the relationship

between the two forms of trust in the past”. Looking at previous studies in the literature (see point 1), this is hardly correct (they do employ a wide variety of controls at the individual level).

We agree that the studies we review in the introduction do employ many individual-levels control (e.g., age, gender, education, to mention a few). We originally used the term “individual differences” in the manuscript as used in the psychological literature (e.g., personality traits, attitudes, or values). We now changed this wording, and clarified this both in the introduction while discussing the control variables (p. 8) and in the overall discussion (p. 30).

Also, while using controls in Studies 1 and 2 makes perfect sense because they are observational studies, Study 3 is an experiment and it shouldn’t require controls if the randomization worked properly. Including controls for Study 3 should be justified by arguing that you are adjusting for (potential) differences in baseline covariates across the different conditions.

We agree that the aim of the inclusion of control variables in Study 3 should be differentiated from the two observational studies. We have specified it in the “Control variables” section of Study 3 (p. 24).

3. There is no explanation or description of the pilot in the main text – the authors briefly mentioned it in the literature review at p. 11: “Thus, for a better understanding of the relation between institutions and interpersonal trust, in the next section, we will focus on research addressing the effect of institutional trust on interpersonal trust. In S1 Appendix we report the results of an additional experimental pilot study that manipulated the presence vs. absence of institutions, and provided evidence for its cascading effects on institutional trust, trusting beliefs, and trusting behavioral intentions towards a stranger”. I would suggest the authors to provide a more detailed justification of the pilot in the general description of their work.

In the revised manuscript, we introduced the pilot study differently and related it to existing literature (p. 5). We did not provide extensive detail about it as the tested model is different (i.e., institutional trust as a mediator and not as a predictor) and we did not want it to become a source of confusion.

4. The manuscript requires a careful revision of the text. Sometimes sentences appear quite disconnected, or are simply inconsistent with the rest of the paragraph. I report here a couple of cases, but an accurate double-check is required. Examples, p.15: “The whole research was conducted in accordance with the Declaration of Helsinki (7th revision, 2013) and local ethical guidelines for experimentation with human participants and was approved by the institutional review board at the University of Turin and by the ethical commission of the Zeppelin University in Friedrichshafen. All subjects gave written informed consent prior to the experiment. To avoid sequence effects, in Studies 1 and 3 all items were presented in a randomized order within each scale and, unless otherwise stated, they were answered on a seven-point Likert scale from 1 (I do not agree) to 7 (I totally agree)”.

At p. 17 (while describing Study 1): “From these items, we created a general aggregated measure of institutional trust by averaging scores of these five scales. As in Study 1, trusting beliefs toward Italian

citizens were measured through the adapted General Trust Scale ([23], α = .93)”.

Thank you for this suggestion. We revised these and other sentences in the manuscript to improve the flow.

5. In the manuscript, the authors often discuss the direct impact of institutional trust on interpersonal trust. Fig. 1, however, does not represent this accurately (as it shows only an effect on trusting behavior). Thus, I would suggest to modify Fig.1 and make it more consistent with the authors’ general argument/interpretation of results. Here is a possible “solution” (apologies for the sketchy picture):

We agree that such an edit would make the figure more consistent with the model that has been tested across the three studies. We appreciated the proposed suggestion and your effort in providing us a possible solution. We adapted Fig. 1 accordingly.

Study 1

The contribution of Study 1 is difficult to grasp at the moment. Indeed, since it does not employ a representative sample of the population and there is no manipulation (not sure if it makes sense to report the results of the sensitivity analysis at p.16), Study 1 appears to contribute very little to the discussion, especially in comparison to Studies 2 and 3. I suggest to move Study 1 to the SI to give more space to Studies 2 and 3, which require more information. If the authors disagree with this comment, I believe they should better justify the value/input of Study 1 (i.e. how does this study exactly improve on our current knowledge of this relationship?). The following passage at p. 20 provides a good hint on where to start (from my point of view): “This different operationalization of interpersonal trust would allow to relate our findings to previous evidence from survey studies using this scale (e.g., [36]) and to generalize them above specific trust targets (i.e., members of own community such as Italian citizens in Study 1)”.

Thank you for this input. It gave us the chance to clarify the exact contribution of Study 1 to the entire set of studies (p. 9, p. 27). The main contribution we describe in the manuscript is to provide the possibility to generalize the results across the three studies, that used different operationalizations of the constructs:

- Study 1 adopted the 3-items measure of feelings of security for the first time and showed its reliability. This allowed to adopt the same measure in Study 3;

- Study 1 used the same measure of trusting beliefs adopted in Study 3, but toward a different target (i.e., Italian citizens and the partner in the trust game, respectively);

- Study 1 measured institutional trust using scales that focus on competence, benevolence, and integrity of public institutions (Hofmann et al., 2014), which provides several advantages as compared to the standard “confidence in the following institutions” items (also adopted in the ESS).

We hope that, in light of the new information we added, we were able to convey why we think that the study should be discussed in the main text together with the evidence from the other studies.

Study 2

1. Given that the mediation mechanism does not involve level 2 (i.e. country-level) variables and they are not interested in exploring the impact of any country-level variables on trust, I don’t see why the authors use multilevel mediation. Instead, they could simply control for all country differences (i.e. having countries as a fixed-effect, as they do for survey-years). This should tell us whether the mediation effect is working across countries, which would be more relevant/interesting for their analysis. If the mediation effect is not working once they control for countries, then it might be interesting to understand why this is the case/for which countries the mediation works/what country-level factors are important in this respect (re-introducing the multi-level mediation here).

Thank you for the suggestion. In the original analyses we used countries as random effects following previous research (e.g., Romano et al., 2017) but, indeed, the model specification you suggest could also be appropriate to test our hypotheses (as the involved variables are measured at the individual level). We now run these additional analyses and reported the mediation analyses with countries as control in the results section (p. 19), showing consisting results across the two model specifications. These results are presented in detail in S5 Table.

2. Considering that in Study 3 the authors are manipulating trust towards the police (rather than the broader concept of institutional trust), it would be good to have a separate part of the analysis focusing on the same aspect in Study 2 (trust in the police � feelings of security � generalized trust). This would also help the reader to see more clearly the link between the two studies.

We followed this suggestion and report the results using trust in the police as predictor in a separate section in Study 2 (p. 19). Additionally, in S4 Table and S5 Table we report the results for trust in all the single institutions taken separately.

3. As mentioned in the general comments section, I believe that Study 2 needs a table where you concisely present the results from the mediation model (i.e. the different paths for direct and indirect effects) with and without covariates (e.g. Model 1 no controls, Model 2 controls at the individual level, Model 3 controls for countries and survey-years).

Done, this table is referred in the manuscript as S4 Table.

Study 3

1. Study 3 requires a more detailed presentation of the design (e.g. how many sessions did you have? How many people per session? It would be good to have more details on the trust game – one-shot? Strategy method? How much could the trusters send? What was the multiplier? Etc.). At the moment, it is difficult to understand what the subjects exactly experienced and in which order (e.g. did they play the trust game after the questions on trusting beliefs? Did the questions on expectations of reciprocity followed the trust game?). This is important to properly evaluate the results of the study.

We have now provided more detail about the game paradigm including endowment, multiplier, and detailed information on how financial rewards for participants have been calculated (p. 23).

Also, we have re-structured the procedure section to clarify the different stages of the process (including in which order we assessed all the variables). To this purpose, we now created four sections in the procedure, describing (1) Experimental manipulation (institutional trust), (2) Manipulation checks, (3) Dependent variables (trusting beliefs and behavior) and mediating variables (feelings of security and expectations of reciprocity), and (4) Control variables.

2. The type of behavioural trust you are measuring here is quite different from the one measured in Studies 1 and 2. Indeed, here subjects are asked whether they would trust someone from another country (i.e. Country X – trustee’s home country. Side note: it would be good to know why you had those 11 countries, on which basis you selected them etc.). This is not equivalent to measuring trust towards unknown fellow citizens/strangers, as the form of trust measured in Study 3 involves a stronger out-group component (it should be closer to trust towards migrants). The theoretical framework of Study 3 should discuss this issue and interpret findings accordingly.

We agree, and therefore now discuss how employing different trust target for the “strangers” would enhance our understanding of our evidence, mentioning that it allows the generalizability of the results in light of the trust radius problem (Delhey et al., 2011) (p. 27)

Additionally, we have now made more explicit the reason why we selected the specific countries (p. 22).

3. In my view, deception could have been avoided (by designing the experiment more carefully). I would invite the authors to justify their decision, explaining why deception was needed in this case.

We are happy to clarify. Although norms in psychological research are traditionally more lenient than other disciplines (e.g., experimental economics) when it comes to using deception, we agree that this should be avoided if the same experimental rigor can be obtained without it.

In this study, we aimed to provide an experimentally controlled manipulation of institutional trust by providing participants with very specific information about the institutions in place in the trustee’s country. To test such an effect on behavior for the first time, it was crucial to make sure to set up a clean situation in which any observed effect would be attributable to this randomly assigned information and not to any other pre-existing information about the partner.

Accordingly, one way to avoid deception here would have involved running the studies across cultures (e.g., matching participants from a high vs a low trusting countries) and providing real statistics of institutional performance. However, at the time the research was conducted we did not have the resources to access to such participants pools. An alternative setting would have required to ask participants to make a hypothetical decision (i.e., behaving as if they would do in a real situation).

We now clarified in the manuscript which specific purpose served the use of deception in this study (p. 23) and encourage future studies to extend our findings without using it (p. 31).

4. Recoding of trusting behavior in Table S4 does not seem consistent with results presented at p.26: “On average, participants transferred 70.6% (SD = 26.7%) of their initial endowment to the trustee, […] (see S4 Table)”. While in table S4 you report the following:Institutional Trust

Low High

M (SD) M (SD)

Trusting behavior 3.39 (1.39) 3.67(1.28)

How should we interpret the values 3.39 or 3.67 in relation to the value of 70.6%? As mentioned in the general comments, the coding of variables is quite confusing, and it appears to be inconsistent in some passages. Please double-check carefully the manuscript in this respect.

Thank you for pointing this out. Indeed, we realized that the choice range (0-5 lab coins) was not provided in the original text. We extensively re-checked and revised this section (p. 23). We hope this information justifies how the 70.6% was calculated based on the means reported in the table.

5. Table 2 was cut and didn’t properly show the results.

Our apologies if you could not access that information. The Plos One submission guidelines encourage to submit tables even if horizontally spread, as they could be seen and processed in “web layout”. However, we now submitted an auxiliary file in which all tables cited in the manuscript can be accessed and visualized in “print layout” (i.e., the default view for Word files) to facilitate the review process.

6. I would like to invite the authors to elaborate more on the mediation effect reported in Study 3. Indeed, while there is no significant direct effect from the manipulation of trust (towards the police) to trusting behaviors, the analysis suggests that there is a significant indirect effect (through feelings of insecurity). Is this a case of indirect-only mediation (e.g. Zhao, X., Lynch Jr, J. G., & Chen, Q. 2010. Reconsidering Baron and Kenny: Myths and truths about mediation analysis.)? Or is it actually due to a moderating effect? Also, how is this consistent with results reported in Study 2 where, in my understanding, we have both significant direct and indirect effects? How do the authors explain this difference? How should we interpret findings from Studies 2 and 3 once taken together?

Thanks for the opportunity to elaborate more on the effects reported in Study 3. Reviewer 1 similarly pointed out the lack of a main effect in that study. We carefully addressed this point in the revised version of the manuscript. Please see above our response to Reviewer 1’s remark.

Overall, we now discuss possible interpretations of the findings of the three studies taken together and we suggest directions for future research (p. 30-31) that might contribute to a further understanding of the phenomenon.

As to your suggestion about an interaction effect being present, we do not think this is the case in the current study as we find that our experimental manipulation has a main effect on feeling of security (t = -7.793, p < .001) and that the indirect effect was consistent even after controlling for an independent and stable disposition (i.e., how much participants valued security in their life). Of course, there is the possibility that potential moderator variables might influence the relationship on top of this effect (e.g., a general need for security and protection, Mayseless & Popper, 2007). We think this is an interesting question, but it might deserve to be pursued in a separate project aiming at tackling such interaction.

Reviewer #3

1) I think the paper could cite the existing and quite large literature in economics on the relationship between institutions and trust, in particular the work by Luigi Guiso and Guido Tabellini.

We acknowledge the following additional references from the economic literature as particularly relevant for our literature review:

Guiso, L., Sapienza, P., & Zingales, L. (2016). Long-term persistence. Journal of the European Economic Association, 14(6), 1401-1436.

Tabellini, G. (2008). Institutions and culture. Journal of the European Economic Association, 6(2-3), 255-294.

Ljunge, M. (2014). Social capital and political institutions: Evidence that democracy fosters trust. Economics Letters, 122(1), 44-49.

2) I am not sure about the value added of Study 1. Study 2 also uses observational data and therefore suffers from the same problem as Study 1, but is superior and more powerful given the larger number of observations and the different countries. In my view, Study 2 makes Study 1 redundant. If the authors decide on keeping Study 1, I encourage them to point out more clearly the differences to Study 2, and in particular what we learn from Study 1 that we do not learn from Study 2.

Following your and Reviewer 2’s suggestions, we now clarify how exactly Study 1 contributes to our understanding of the relationship between interpersonal and institutional trust, and how it relates to Study 2 in this manuscript (p. 9, p. 27). You can find our response above under the Study 1 paragraph). Also, we now mention the value of having a different target of interpersonal trust (more oriented toward the ingroup members), in combination with the other targets of interpersonal trust (p. 27).

3) Statistical Analysis: Overall, the statistical analysis is conducted appropriately, but I have some questions:

- Do you include country or subnational region fixed effects in Study 2? They would absorb many fixed institutional and economic characteristics of a country or region that could affect institutional trust and trust in strangers.

The analyses reported in the original manuscript did not include countries as fixed effects.

As a robustness check, and as suggested by Reviewer 2, we conducted additional analyses and tested our hypotheses with countries as fixed effects. We comment such analyses in the revised version of the manuscript (p. 19) and report the details in S5 Table)

- For the reader it would be interesting to know for each study what is the percentage of the effect of total effect of institutional trust on trust that is mediated by safety considerations.

We now report the percentage of the effect accounted for by the mediator in all mediation analyses performed in Study 3 (Table 2, S4 Table, S5 Table). However, we did not provide the information for Study 1 and 3, as literature suggests that the proportion mediated should be reported only when N ≥ 500 (Fairchild & McDaniel, 2017; MacKinnon et al., 1995) and therefore it could have raised interpretability concerns.

- The t-test you mention is not clear to me (“On average, participants transferred 70.6% (SD = 26.7%) of their initial endowment to the trustee, and no differences emerged for either trusting beliefs... “ Do you test the difference in money transferred between the two experimental groups? What is the result?

This is correct. We disambiguated this issue both extensively revising the procedure section (e.g., specifying the choice range 0-5) (p. 23), and the description of the t-test in the results (p. 25).

“Results of the t test showed no differences between the two experimental groups in either trusting beliefs toward the trustee, t(92) = -1.00, p = .317, R2 = .01, nor trusting behavior, t(92) = -1.00, p = .321, R2 = .01 (see S6 Table)”.

4) Presentation of results:

- I find the tables not easy readable and not very intuitive. For example, variable names are not intuitive, number of observations are missing, and it is not clear from the table what are the control variables included in the regressions.

- There is no Table with results for Study 2.

- Table 2 that contains the results for Study 3 is too large and half of it is not readable.

Thank you for the remarks. We now created new tables for all the three studies (Table 1, 2, 4) with more intuitive labels and additional information (i.e., path from the mediator to the outcome variable, total effect, direct effect, indirect effect). In the notes, we report which exactly the control variables were used for each model, together with the number of observations.

As for the readability of large tables, we apologized if you couldn’t have access to the full information while reviewing the manuscript. As we mentioned to Reviewer 2 who raised a similar point, we now submitted an auxiliary file in which all tables cited in the manuscript can be accessed and visualized to facilitate the review process.

References

Delhey, J., Newton, K., & Welzel, C. (2011). How general is trust in “most people”? Solving the radius of trust problem. American Sociological Review, 76(5), 786–807. https://doi.org/10.1177/0003122411420817

Fairchild, A. J., & McDaniel, H. L. (2017). Best (but oft-forgotten) practices: Mediation analysis. American Journal of Clinical Nutrition, 105(6), 1259–1271. https://doi.org/10.3945/ajcn.117.152546

Herreros, F., & Criado, H. (2008). The State and the development of social trust. International Political Science Review, 29(1), 53–71. https://doi.org/10.1177/0192512107083447

Hofmann, E., Gangl, K., Kirchler, E., & Stark, J. (2014). Enhancing tax compliance through coercive and legitimate power of tax authorities by concurrently diminishing or facilitating trust in tax authorities. Law and Policy, 36(3), 290–313. https://doi.org/10.1111/lapo.12021

Irwin, K. (2009). Prosocial behavior across cultures: The effects of institutional versus generalized trust. In S. R. Thye & E. J. Lawler (Eds.), Advances in Group Processes (Vol. 26, pp. 165–198). Emerald Group Publishing Limited. https://doi.org/10.1108/S0882-6145(2009)0000026010

Lo Iacono, S. (2019). Law-breaking, fairness, and generalized trust: The mediating role of trust in institutions. PLoS ONE, 14(8), e0220160. https://doi.org/10.1371/journal.pone.0220160

MacKinnon, D. P., Warsi, G., & Dwyer, J. H. (1995). A simulation study of mediated effect measures. Multivariate Behavioral Research, 30(1), 41–62. https://doi.org/10.1207/s15327906mbr3001_3

Mayer, R. C., Davis, J. H., & Schoorman, F. D. (1995). An integrative model of organizational trust. Academy of Management Review, 20(3), 709–734. https://doi.org/10.5465/amr.1995.9508080335

Mayseless, O., & Popper, M. (2007). Reliance on leaders and social institutions: An attachment perspective. Attachment and Human Development, 9(1), 73–93. https://doi.org/10.1080/14616730601151466

Moin, S. M. A., Devlin, J., & McKechnie, S. (2015). Trust in financial services: Impact of institutional trust and dispositional trust on trusting belief. Journal of Financial Services Marketing, 20(2), 91–106. https://doi.org/10.1057/fsm.2015.6

Nannestad, P., Svendsen, G. T., Dinesen, P. T., & Sønderskov, K. M. (2014). Do institutions or culture determine the level of social trust? The natural experiment of migration from non-western to Western countries. Journal of Ethnic and Migration Studies, 40(4), 544–565. https://doi.org/10.1080/1369183X.2013.830499

Robbins, B. G. (2011). Neither government nor community alone: A test of state-centered models of generalized trust. Rationality and Society, 23(3), 304–346. https://doi.org/10.1177/1043463111404665

Romano, A., Balliet, D., Yamagishi, T., & Liu, J. H. (2017). Parochial trust and cooperation across 17 societies. Proceedings of the National Academy of Sciences of the United States of America, 114(48), 12702–12707. https://doi.org/10.1073/pnas.1712921114

Rothstein, B., & Eek, D. (2009). Political corruption and social trust. Rationality and Society, 21(1), 81–112. https://doi.org/10.1177/1043463108099349

Rothstein, B., & Stolle, D. (2008). The state and social capital: An institutional theory of generalized trust. Comparative Politics, 40(4), 441–459. https://doi.org/10.2307/20434095

Rousseau, D. M., Sitkin, S. B., Burt, R. S., & Camerer, C. (1998). Not so different after all: A cross-discipline view of trust. Academy of Management Review, 23(3), 393–404. https://doi.org/10.5465/AMR.1998.926617

Seifert, N. (2018). Yet another case of Nordic exceptionalism? Extending existing evidence for a causal relationship between institutional and social trust to the Netherlands and Switzerland. Social Indicators Research, 136(2), 539–555. https://doi.org/10.1007/s11205-017-1564-x

Shrout, P. E., & Bolger, N. (2002). Mediation in experimental and nonexperimental studies: New procedures and recommendations. Psychological Methods, 7(4), 422–445. https://doi.org/10.1037/1082-989X.7.4.422

Yamagishi, T., & Mifune, N. (2008). Does shared group membership promote altruism? Rationality and Society, 20(1), 5–30. https://doi.org/10.1177/1043463107085442

Zhao, X., Lynch, J. G., & Chen, Q. (2010). Reconsidering Baron and Kenny: Myths and Truths about Mediation Analysis. Journal of Consumer Research, 37(2), 197–206. https://doi.org/10.1086/651257

Zmerli, S., & Newton, K. (2008). Social trust and attitudes toward democracy. Public Opinion Quarterly, 72(4), 706–724. https://doi.org/doi:10.1093/poq/nfn054

Attachment

Submitted filename: Response to Reviewers.docx

Decision Letter 1

Valerio Capraro

23 Jun 2020

PONE-D-20-07477R1

Enhancing feelings of security: How institutional trust promotes interpersonal trust

PLOS ONE

Dear Dr. Spadaro,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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We look forward to receiving your revised manuscript.

Kind regards,

Valerio Capraro

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PLOS ONE

Additional Editor Comments (if provided):

I have now collected three reviews from the same reviewers who reviewed the first version of this manuscript. One review is positive and accepts the manuscript, another review is also positive and suggests a very minor revision, the third review is still negative, but leaves to the editor the ultimate decision. After reading the manuscript and the reviews, I have decided to follow the majority of the reviewers and conditionally accept this manuscript. Please address the remaining comments at your earliest convenience. I am looking forward for the final version.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

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Reviewer #3: All comments have been addressed

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Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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Reviewer #1: Thank you for the opportunity to review this revision. The authors certainly took seriously my concerns and I appreciate their detailed responses. Unfortunately, however, I remain largely unpersuaded by the contribution of this work. It provides arguably interesting data with less than clear findings to a well-researched area in a way that just seems to muddy the water. I must leave to the editor whether this contribution is sufficient.

On the positive side, I buy the authors' argument that the idea that security might explain the institutional/interpersonal relationship is novel but it is not argued particularly well here and as a result, it is hard to see how the paper could stand on its conceptual contribution (the paper does more to say "it could be argued" than to show a concrete logic upon which future, more precise tests can rest).

Additionally, Study 2 appears pretty solid. I am curious about the operationalization of security but I understand that this is secondary data and the argument that the four institutions have some nexus with crime control is persuasive.

On the negative side, Study 1 still has huge common method variance issues (all three of the focal measures address really similar concepts--the trustworthiness of institutions, whether those institutions create feelings of security, and trust in "most Italians" [which presumably include the people who work for the institutions]). I recognize the attempt to control out these issues and the argument that this is only one piece of a larger puzzle but there still is not much "there" there.

Study 3 still has the same issues I brought up in my first review and I was largely unpersuaded by the authors' response. There is still no good reason why a participant would use information about the police in a country where an interaction partner was located to set trust in that individual UNLESS that was literally the only information to go on (as is the assumption here given that this is a manipulation). Thus, this does not represent the actual process within a country and so whatever relation is identified (even if consistent with the one in reality) happened for a different reason. Problematically though, that this manipulation still does not result in a direct effect on interpersonal trust remains a problem. I recognize and appreciate the authors' citations of work arguing that this is not a prerequisite of a significant indirect effect so I will stipulate that the indirect effect may exist but the lack of a direct effect supports my contention that the process here is different. We know that institutional trust should covary with interpersonal. That they do not suggests that something is off here.

For smaller issues, the paper still uses Mayer's definition of trust to motivate work on what those authors would call trustworthiness. This just feels unnecessary. As the authors note in the response to reviewers, they root their work in trust defined differently--why not present that as the core definition?

Additionally, the paper would benefit from a read-through for missing words, typos, and word choice.

Reviewer #2: The authors have addressed very well all points raised, and I believe that the manuscript should be published.

I have only few minor remarks:

- Table 4 (p.26) can still be improved and better show the results for the serial mediation model e.g. results for mediator 2 are not clear (in my view).

- The "General Discussion" is sometimes at odds with the "Limitations and Future Research" section. I would invite the authors to double-check for inconsistencies (even if small).

- The "Concluding Remarks" could be toned down a bit and be reviewed to be more in line with the rest of the manuscript (e.g. this sentence does not fit well with your review of the literature "Decades of research have focused on several processes that may promote trust among strangers, but very little attention has been devoted on one recurrent feature that characterize modern human interactions: the presence of institutions)".

Reviewer #3: (No Response)

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PLoS One. 2020 Sep 11;15(9):e0237934. doi: 10.1371/journal.pone.0237934.r004

Author response to Decision Letter 1


2 Aug 2020

Dear Dr. Valerio Capraro,

Thank you for conditionally accepting our revised manuscript (PONE-D-20-07477), entitled “Enhancing feelings of security: How institutional trust promotes interpersonal trust”, to be considered for publication in Plos One. We are grateful for the helpful feedback that the reviewers have provided, and for the opportunity to improve our work.

We carefully addressed the remaining issues in this further round of revisions; we hope that this revised version can solve all the remaining concerns. In particular, in the response letter and in the manuscript, we further clarified some concern raised by Reviewer 1, and addressed the remaining issues pointed out by Reviewer 2.

For an easier navigation of the revisions, when changes have been made to the manuscript, we insert a section of text from the paper and/or provide the page numbers of the tracked version of the revised manuscript where the revisions can be found. As recommended in the submission guideline, large tables in the manuscript can be fully accessed through the “Web Layout” mode in Microsoft Word.

Editor

E: I have now collected three reviews from the same reviewers who reviewed the first version of this manuscript. One review is positive and accepts the manuscript, another review is also positive and suggests a very minor revision, the third review is still negative, but leaves to the editor the ultimate decision. After reading the manuscript and the reviews, I have decided to follow the majority of the reviewers and conditionally accept this manuscript. Please address the remaining comments at your earliest convenience. I am looking forward for the final version.

A: Thanks for conditionally accepting our manuscript. We greatly appreciate the opportunity to further improve the manuscript. We hope that you consider our revisions as raising the manuscript to the level expected at Plos One.

Reviewer #1

R1: Thank you for the opportunity to review this revision. The authors certainly took seriously my concerns and I appreciate their detailed responses. Unfortunately, however, I remain largely unpersuaded by the contribution of this work. It provides arguably interesting data with less than clear findings to a well-researched area in a way that just seems to muddy the water. I must leave to the editor whether this contribution is sufficient.

On the positive side, I buy the authors' argument that the idea that security might explain the institutional/interpersonal relationship is novel but it is not argued particularly well here and as a result, it is hard to see how the paper could stand on its conceptual contribution (the paper does more to say "it could be argued" than to show a concrete logic upon which future, more precise tests can rest).

Additionally, Study 2 appears pretty solid. I am curious about the operationalization of security but I understand that this is secondary data and the argument that the four institutions have some nexus with crime control is persuasive.

A: Thank you for your comments on the revised version of the manuscript. We are glad our revision improved your confidence on our findings regarding the contribution of this work and, in particular, the test of the mediating role of feelings of security in the relation between institutional trust and interpersonal trust (especially in light of the evidence provided in Study 2).

R1: On the negative side, Study 1 still has huge common method variance issues (all three of the focal measures address really similar concepts--the trustworthiness of institutions, whether those institutions create feelings of security, and trust in "most Italians" [which presumably include the people who work for the institutions]). I recognize the attempt to control out these issues and the argument that this is only one piece of a larger puzzle but there still is not much "there" there.

A: We understand your concern. However, based on the data and on past research, we are confident that each measure underlies a different construct, and therefore our results are not due to common method variance, for three main reasons:

(a) The correlations among those variables are not as strong to suggest that there is a concerning overlapping between constructs (ranging from r = .28 to r = .50; S2 Table, p. 12). Given the correlation between institutional trust and feelings of security (r = .50), we additionally run two confirmatory factor analyses to compare the model fit of either one or two latent factors, to rule out a possible overlap between the two variables and found evidence for a better fit of the two-factors model (see S2 Text);

(b) In Study 2 and 3 we used different operationalizations of the constructs and found a consistent pattern of results. For example, Study 2 operationalized feelings of security through a measure that is not tied to institutions, and interpersonal trust with a question that refers to “most people”; Study 3 manipulated (rather than measured) institutional trust and included a measure of trusting behavior (see S1 Table for an overview);

(c) These measures are grounded in past research and were operationalized from specific theories (e.g., Yamagishi & Yamagishi, 1994).

In the current version of the manuscript, to better clarify the different operationalizations and past research from which we selected these measures, we direct the reader to S1 Table (p. 8).

R1: Study 3 still has the same issues I brought up in my first review and I was largely unpersuaded by the authors' response. There is still no good reason why a participant would use information about the police in a country where an interaction partner was located to set trust in that individual UNLESS that was literally the only information to go on (as is the assumption here given that this is a manipulation). Thus, this does not represent the actual process within a country and so whatever relation is identified (even if consistent with the one in reality) happened for a different reason.

A: We agree with you that there is “still no good reason why a participant would use information about the police in a country where an interaction partner was located to set trust in that individual UNLESS that was literally the only information to go on”.

That said, this is exactly what we did with our experimental manipulation when we decided not to provide the name of the partner’s country, but now realized this was not explicitly stated in the text. In the current version of the manuscript, we now add two sentences where we explicitly mention this aspect (see p. 21, 22). Hence, participants should base their trust assessments and made their trusting decision based on the information about institutions, as also done in previous research on trust and institutions (see Rothstein & Eek, 2009).

Nevertheless, we agree that the ecological validity of the manipulation might not be optimal, but the choice of the experimental method should be understood as a complement to the other methods and data we gathered from different sources.

R1: Problematically though, that this manipulation still does not result in a direct effect on interpersonal trust remains a problem. I recognize and appreciate the authors' citations of work arguing that this is not a prerequisite of a significant indirect effect so I will stipulate that the indirect effect may exist but the lack of a direct effect supports my contention that the process here is different. We know that institutional trust should covary with interpersonal. That they do not suggests that something is off here.

A: We are glad you agree with us that the presence of the indirect effect supports one major goal of the paper.

We agree that the lack of a null effect leaves open questions on what could have driven such null effect. However, contrary to what you suggest, the null effect itself is not enough to support specific alternative explanations (as we cannot claim that the null hypothesis is true). As we discuss in the General Discussion section, we believe that there are two potential possibilities which explain these findings. First, in our manipulation of institutional trust in Study 3, the institution does not have a direct intervening role in the game (e.g., the police do not have the power to regulate the social exchange). Another possibility is that the information about the institution learned in this context in light of a one-shot interaction is not comparable to trust assessments toward existing institutions, that are built through recurrent exposure. Both aspects are mentioned in the Limitation and future research section and the discussion of findings of Study 3 (p. 32 and p. 27, respectively).

Additionally, we now explicitly mention the lack of a main effect in Study 3 in the overall summary of the findings provided in the General discussion of the revised version of the manuscript (p. 28).

R1: For smaller issues, the paper still uses Mayer's definition of trust to motivate work on what those authors would call trustworthiness. This just feels unnecessary. As the authors note in the response to reviewers, they root their work in trust defined differently--why not present that as the core definition?

A: In the manuscript, we refer to the definition provided by Mayer and colleagues (1995) to define interpersonal trust (p. 2), as it is defined as “[...] the willingness of a party to be vulnerable to the actions of another party based on the expectation that the other will perform a particular action important to the trustor, irrespective of the ability to monitor or control that other party” (p. 712), and captures well the component related to risk and vulnerability enclosed in trust toward strangers, which is the outcome variable of all the studies presented in the manuscript. Additionally, this work motivated our choice of controlling for trust propensity as individual disposition in Study 1 and 3, as this variable is explicitly acknowledged in the model proposed by the authors. For these reasons, we would prefer to keep this citation unless the Editor has a strong preference about it.

That said, we acknowledge that we have used a different definition for institutional trust, based on the work of Devos and colleagues (2002), which is currently presented at p. 5, while discussing research on institutional trust.

R1: Additionally, the paper would benefit from a read-through for missing words, typos, and word choice.

A: Thanks for the suggestion. We made several edits across the entire body of manuscript to improve its readability and address any typo or missing word(s).

Reviewer #2

R2: The authors have addressed very well all points raised, and I believe that the manuscript should be published.

I have only few minor remarks:

- Table 4 (p.26) can still be improved and better show the results for the serial mediation model e.g. results for mediator 2 are not clear (in my view).

A: We are glad you found our revision of the manuscript adequate to address most of your concerns.

In this revised version, we now clarify how the estimates reported in the table for mediator 1 and 2 were obtained by including a specific remark in the note:

“*Estimates of regressions of the mediators (feelings of security and trusting beliefs, respectively) predicting trusting behavior.” (p. 26)

We maintained the same structure of the table to be consistent with all the other mediation tables reported in the manuscript, but added an explicit reference to the “serial mediation models” in the heading to differentiate it from the tables summarizing models with a single mediator.

We made the same set of edits in Table B in the SI (p. 10), which summarizes a serial mediation as well.

R2: The "General Discussion" is sometimes at odds with the "Limitations and Future Research" section. I would invite the authors to double-check for inconsistencies (even if small).The "Concluding Remarks" could be toned down a bit and be reviewed to be more in line with the rest of the manuscript (e.g. this sentence does not fit well with your review of the literature "Decades of research have focused on several processes that may promote trust among strangers, but very little attention has been devoted on one recurrent feature that characterize modern human interactions: the presence of institutions)".

A: Following your comment, we revised the three sections of the General discussion section and double-checked the text to remove any inconsistencies among them and the literature review presented in the introduction.

For example, we replaced “(...) the lack of a main effect of institutional trust in Study 3, which does not replicate what we found in Study 1 and 2” with “(...) the lack of a main effect of institutional trust in Study 3, which was observed in Study 1 and 2” (Limitations and Future Research, p. 31), as it might have seemed at odds with claims such as “That being said, the present findings appear robust and generalizable across research methodologies and variables operationalizations, and remain consistent even when controlling for relevant individual characteristics and institutional performance indicators” (Limitations and Future Research, p. 32).

We decided to completely remove the sentence you mentioned from the “Concluding Remarks” as it looked, indeed, at odds with the content in the abstract and in the literature review. Instead, we wrote a summary sentence coherent with the goals and theoretical rationale as opening of the General Discussion section (p. 27).

References:

Devos, T., Spini, D., & Schwartz, S. H. (2002). Conflicts among human values and trust in institutions. British Journal of Social Psychology, 41(4), 481–494. https://doi.org/10.1348/014466602321149849

Mayer, R. C., Davis, J. H., & Schoorman, F. D. (1995). An integrative model of organizational trust. Academy of Management Review, 20(3), 709–734. https://doi.org/10.5465/amr.1995.9508080335

Rothstein, B., & Eek, D. (2009). Political corruption and social trust. Rationality and Society, 21(1), 81–112. https://doi.org/10.1177/1043463108099349

Yamagishi, T., & Yamagishi, M. (1994). Trust and commitment in the United States and Japan. Motivation and Emotion, 18(2), 129–166. https://doi.org/10.1007/BF02249397

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Decision Letter 2

Valerio Capraro

6 Aug 2020

Enhancing feelings of security: How institutional trust promotes interpersonal trust

PONE-D-20-07477R2

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Acceptance letter

Valerio Capraro

18 Aug 2020

PONE-D-20-07477R2

Enhancing feelings of security: How institutional trust promotes interpersonal trust

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