Alcohol’s Effects on the Bystander Decision Making Model: A Systematic Literature Review

Abstract

To decrease rates of sexual assault victimization, young people are encouraged to become involved when they see questionable sexual situations (i.e., be a prosocial bystander). Several factors can inhibit or facilitate someone from intervening, including alcohol use. To inform bystander prevention programs which aim to address alcohol’s impact on bystanders, the current study reviewed research focused on alcohol use and bystander decision making. In December 2022, the authors searched published studies from six major electronic databases. Empirical articles were deemed eligible if they examined alcohol and the bystander decision making model within the context of sexual assault, were based in the US or Canada, and not an intervention study; 32 studies were included in the final review. Across 32 studies published between 2015-2022, 12 assessed the proximal effects of alcohol on bystander constructs and the additional studies examined the distal effects of alcohol on bystander constructs. Alcohol use appeared to impede earlier steps of the bystander decision making model; however, alcohol use was associated with impeding and facilitating bystander decision making at the latter half of the model. Overall, alcohol use appears to be negatively rather than positively associated with bystander constructs. Bystander intervention programs may want to move beyond the narrative of alcohol as a risk factor for sexual assault and discuss how alcohol impairs a bystanders’ ability to recognize risk. More work is needed to ensure researchers assess alcohol consistently and with similar methods (number of drinks, subjective intoxication) to increase generalizability of findings to prevention programs.

Introduction

Sexual assault victimization continues to be a pervasive problem for young women and associated with myriad health and economic consequences (Dworkin, 2018; Dworkin et al., 2017; Hequembourg et al., 2015; Muehlenhard et al., 2017; Peterson et al., 2017). Given the pervasiveness and consequences associated with sexual assault victimization, researchers and educators aim to prevent sexual assaults from happening. One form of sexual assault prevention focuses on training third-party people or bystanders, to intervene when they see high-risk sexual situations (Banyard, 2008; Banyard, 2015). However, several factors can inhibit or facilitate someone from intervening in a sexual assault situation, including a bystander’s alcohol use. Indeed, increased attention has been placed on the role that distal and proximal effects of alcohol use has on bystander attitudes and behaviors in recent years (Ham et al., 2019; Jozkowski, Marcantonio et al ., 2022; Leone et al., 2018; Leone & Parrott, 2019; Orchowski et al., 2016; Schipani-McLaughlin et al., 2021; Waterman et al., 2021); yet, a synthesis of this research has not occurred. Thus, the goal of this study was to conduct a systematic literature review of the effects of alcohol on bystander’s decision making and intervention behaviors to help inform researchers and bystander prevention programs.

Bystander Decision Making Model

Bystander intervention is grounded in the Bystander Decision Making Model that suggests people move through five steps prior to intervention (Latane & Darley, 1968). First, someone must notice an event that warrants intervention (Step 1). Second, a person needs to interpret the event they have noticed as concerning, dangerous, or risky (Step 2). Third, a person needs to take intervention responsibility and decide they should help (Step 3). Fourth, the person needs to decide how to help in this situation (Step 4). Finally, the person executes prosocial action or intervention (Step 5). Within the bystander decision making model these steps are discussed linearly; yet, in the moment, they might not occur in perfect sequence. A bystander may revert to earlier steps of the model as new information becomes available or as a lower-risk situation (e.g., a man persistently hitting on an intoxicated woman) escalates to higher-risk one (e.g., the same man tries to take her to an isolated location; Banyard, 2015). Bystanders may continuously re-evaluate a situation to decide if intervention is warranted. Bystanders may also be presented with different barriers that can inhibit intervention (Burn, 2009), such as alcohol use and intoxication (Bridges et al., 2021; Ham et al., 2019; Leone & Parrott, 2019; Melkonian et al., 2020).

Alcohol Use and The Bystander Decision Making Model

In a recent theoretical review, Leone and colleagues (2018) outlined how alcohol could impact a bystander at each step of the bystander decision making model. Their team integrated the bystander decision making model with a well-tested theory on how alcohol impacts behavior, alcohol myopia theory (Steele & Josephs, 1990). According to alcohol myopia theory, the pharmacological properties of alcohol restrict and narrow attentional focus to the most salient, provocative cues in an environment to the exclusion of less salient, non-provocative cues. To this end, this integrated model suggests that alcohol should increase barriers to intervention at each step of the bystander decision making model. For instance, at Step 1, alcohol intoxication may impede someone’s ability to notice an event because they are susceptible to distractions. At Step 2, alcohol intoxication could cause someone to misinterpret cues or fail to identify risky cues (Leone et al., 2018). At Step 3, bystander’s alcohol use may exacerbate diffusion of responsibility as others are around them and alcohol creates feelings of relaxation. Thus, someone may be less likely to perceive themselves as responsible to act. At Step 4, the effects of alcohol could prevent someone from developing an effective plan to bystand. Finally, at Step 5, alcohol may impact someone’s ability to execute action by focusing one’s attention on peer norms that discourage intervention (Leone et al., 2018). Leone and colleagues (2018) posit, however, that alcohol can not only inhibit, but also facilitate bystander behavior at certain steps in the decision making model. Specifically, at Step 4, by promoting liquid courage to intervene and at Step 5 by facilitating attention to prosocial attitudes and norms in the environment.

Proximal and Distal Effects of Alcohol Use on Bystander Decision Making

Leone and colleagues (2018) leveraged alcohol myopia theory to suggest how the proximal effects of alcohol use could impact bystander decision making and behavior. Indeed, alcohol myopia theory discusses alcohol’s proximal and pharmacological effects on people’s executive cognitive functioning. Because alcohol intoxication impacts cognitive functioning, alcohol intoxication could also alter behavior. For instance, in being intoxicated from alcohol and knowing intoxication can create challenges with attention, one may be less likely to notice a risky or concerning situation that may need intervention. Thus, when assessing alcohol use as a proximal factor (e.g., intoxication, during ecological momentary assessments), researchers may find that the acute effects of intoxication impede bystander intervention—in line with Leone and colleagues (2018) review.

Leone and colleagues (2018) review did not focus on the distal effects of alcohol on bystander decision making. Researchers who examine the distal effects of alcohol use, such as typical alcohol use, binge drinking, or heavy episodic drinking on bystander decision making may find different results than those who examine the proximal effects. For instance, in assessing how often one binge drinks, researchers may find a positive relationship with Step 1 of the bystander decision making model because binge drinking could be reflective of one being in situations where sexual assault risk is higher, such as a party or bar. Thus, the distal effects of alcohol use could have a positive association with bystander decision making. In summary, researchers may find different results for how alcohol impacts bystander decision making if they assess the proximal or distal effects of alcohol use because the underlying mechanism relating alcohol use and bystander decision making may differ.

Current Study

Since Leone and colleagues (2018) empirical and theoretical review, there has been an increase in research examining the effects of alcohol on bystander decision making. However, no empirical research has confirmed or challenged the hypothesis from their review. As such, a synthesis of the research on alcohol’s effects on the bystander decision making model are needed to summarize current findings. Thus, the goal of this study was to summarize the current empirical literature on the effects of alcohol on the bystander decision making model within sexual assault contexts.

Based on Leone and colleagues (2018) review we hypothesized (H1) that alcohol use would, in general, be negatively associated with prosocial bystander decision making (e.g., noticing an event, risk identification) and intervention behaviors (Steps 1-5). Leone and colleagues did theorize that alcohol use may facilitate bystander decision making and action at Step 4 and Step 5. Thus, we hypothesized (H2) that some researchers may find that alcohol use is positively associated with bystander decision making at the latter half of the model (Step 4 and Step 5).

Finally, we hypothesized (H3) that the impairing effects of alcohol use on bystander decision making would vary when evaluating alcohol’s proximal or distal effects. Specifically, (H3A), we expected more mixed findings for the distal effects of alcohol use on bystander decision making. We hypothesized that some researchers would find that alcohol use was negatively associated with bystander decision making and others would find that alcohol use was positively associated with bystander decision making. We also hypothesized (H3B) more consistent findings for the proximal effects of alcohol use being negatively associated with bystander decision making.

Method

This protocol is being reported in accordance with the Preferred Reporting Items for a Systematic Review and Meta-Analysis (PRISMA). We identified and analyzed 32 full-text studies that included alcohol’s relationship on the bystander decision making process during a sexual assault situation.

Data Sources and Search Strategy

A comprehensive search was conducted by a health sciences librarian (third author) on July 02, 2021 in MEDLINE (via Ovid), SocINDEX (via EBSCOhost), Gender Studies Database (via EBSCOhost), and the following databases in the Web of Science Core Collection: Science Citation Index Expanded (SCI-EXPANDED), Social Sciences Citation Index (SSCI), Arts & Humanities Citation Index (A&HCI), Emerging Sources Citation Index (ESCI) and APA PsycInfo (via EBSCOhost). During the revision process for this study (December, 2022), we updated our search and included articles published between July 31, 2021 to July 31, 2022, to stay within the same time frame of the original search. Search terms for all databases included terms for the following concepts: sexual assault, alcohol intoxication, and bystander intervention. Results were limited to articles published in English. In addition, the MEDLINE, Web of Science, and APA PsycInfo searches also included search filters to exclude animal studies. The complete search strategy for all databases can be found in Appendix 1. Our review is registered with Prospero (CRD42021273111). Results were exported from the databases into Covidence for screening.

Study Selection

The search resulted in 12,587 total records; 4,923 were duplicates and removed, resulting in 7,664 studies. The remaining articles were imported into Covidence, an online software tool for systematic literature reviews. Four reviewers screened the titles and abstracts of the 7,664 articles and 112 were selected for full text review; 32 were included in the systematic review (see Figure 1).

Figure 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Flow Diagrams. Source: Moher, Liberati, Tetzlaff, Altman & the PRISMA Group (2020)

Eligibility Criteria

After duplicate results were removed from the comprehensive search, we conducted title and abstract screening of articles. Studies were included if they were conducted in the United States or Canada and the abstract referenced bystander constructs, alcohol use or alcohol intoxication, and sexual assault. We focused only on studies within the United States or Canada because sexual violence prevention strategies and policies are not seen unilaterally across the globe (e.g., Title IX, White House Task Force to Protect Students From Sexual Assault; Affirmative Consent Policies). Further, there are differences in the legal drinking age across countries which could alter how, when, or where someone bystands. At this stage of screening and given ambiguity in some abstracts, we included articles that referenced gender-based violence, intimate partner violence, and interpersonal violence to ensure we did not remove articles that did assess bystanding during a sexual assault situation. This resulted in 7,552 articles being removed and 112 articles that received a full-text screening.

At full-text screening, studies had to meet the following inclusion criteria: (1) conducted in the United States or Canada, (2) measured both alcohol use and bystander constructs within a sexual assault context, and (3) was an empirical study and not an intervention study. We did not include an age range as bystander intervention is implemented with adolescents in the K-12 system (Waterman et al., 2021) and young adults (Banyard et al., 2004). We also did not include a publication date range to ensure we included any article which examined the effects of alcohol use on bystander decision making.

Articles were excluded if they were focused on other forms of interpersonal violence—such as domestic violence or intimate partner violence but did not include sexual assault. Articles were also excluded if they did not assess how alcohol use was related to the bystander decision making model (e.g., they assessed alcohol and bystander behaviors but did not examine the relationship between the two constructs). The screening process included the first, second, and fourth author along with a graduate research assistant; two coders were assigned to an article and had to agree that a study met the inclusion criteria. Any discrepancies were discussed among the team. This resulted in 32 final articles.

Data Extraction

Upon reaching our final sample of 32 articles, the first author (1) pulled sample characteristics from all articles into excel (e.g., sample size, gender, sexual orientation) and (2) coded whether an article assessed distal effects of alcohol use on the bystander (e.g., through self-report behaviors in surveys or qualitative methodologies) or proximal effects of alcohol use on the bystander (e.g., acute intoxication through field or lab-based studies). The first and second author and a research assistant coded articles to assess how alcohol use (e.g., acute intoxication, self-reported alcohol consumption) was related to the bystander decision making model in sexual assault situations.

Coding process.

Given that our study is focused on assessing how alcohol use is related to the bystander decision making model, our codebook was created deductively and grounded in prior research on the bystander decision making model and alcohol use (Latane & Darley, 1968; Leone et al., 2018). Each article was assessed for whether they measured alcohol’s effect on each step of bystander decision making (Latane & Darley, 1968). Specifically, we coded each article’s result section for the presences of: 1) noticing the event, 2) interpreting the situation as risky, 3) taking intervention responsibility, 4) deciding how to help, and 5) intervention. Additionally, in reviewing the articles for our review and how they measured Step 5, some articles assessed participant’s actual bystander behaviors and others assessed a participant’s intentions to act in a situation. Given that intention to act and acting are different, we added an additional level of coding analysis to Step 5 to assess if researchers measured intervention behaviors or a participant’s intention to act in a situation.

The first author copied the result section of each article into excel and then she and the second author or a research assistant independently coded these results for the presence of each step of the bystander decision making model and how alcohol may have influenced that step. Any discrepancies were discussed until final consensus was reached. After results were coded, they were separated into two categories for each step: alcohol being negatively associated (i.e., impeding) with the bystander decision making model and alcohol being positively associated (i.e., facilitating) with the bystander decision making model. For instance, in step 1, notice the event, we categorized the findings in this step into alcohol use either having a negative or positive influence on the bystander decision making model.

Results

Sample and Article Characteristics

Across the 32 studies, there were 15,172 participants, with 52.6% of the sample including women (n = 7, 980) and 46.9% men (n = 7, 120). The average age across studies was 21.1 (age range 15-25); 70.2% of participants identified as White (n = 10, 655), 30.1% identified as person of color (n = 4,571) and one study did not report participant’s racial or ethnic identity. Three studies only provided the majority group for racial or ethnic identity, which was always White participants.

For the studies that provided a racial or ethnic breakdown, the total sample size was 12, 390 participants. Within this group, 7.9% (n = 987) identified as Latina/o, 7.7% (n = 959) as Asian American/Pacific Islander, 7.0% (n = 871) identified as Black, 6.7% (n = 849) as Native American/American Indian, 3.6% (n = 456) as Bi or Multi Racial, 1.4% (n = 179) as another racial/ethnic identity, and 0.3% (n = 40) had missing racial/ethnic identity information. Across most studies, participants could identify with more than one racial or ethnic group.

Regarding sexual orientation, 16 studies did not report participant’s sexual orientation. Of those that did, 84.4% identified as heterosexual (n = 6,843) and 15.5% of participants identified as a sexual minority person (n = 1,260). Only two studies reported on expansive gender identities, such as non-binary, transwomen, or men; both studies removed those participants from their analytical sample due to an inability to conduct gender comparisons.

Of the 32 articles included in this study, they were all published between 2015-2022; six articles came from the same alcohol administration data collection (see Table 1, articles with an * denote coming from the same data collection). Studies were either peer-reviewed (n = 29) or dissertations (n = 3). The most common types of alcohol assessments focused on participants’ alcohol consumption, including frequency, typical drinking, binge or heavy episodic drinking (n = 19) or were alcohol administration/field-based studies (n = 10). Three of the studies involved interviews or focus groups. Together, 12 studies examined the proximal effects and 20 studies examined distal effects of alcohol on the bystander decision making model (See Table 1).

Table 1.

Summary of how alcohol use related to the bystander decision making model across studies

	Distal Proximal effect of alcohol?	Notice Event	Interpret as Risky	Take Responsibility	Decide how to help	Take action		In line with Leone et al., Theoretical Model?a
Article						Behavior (observed/self-report)	Intent to act
1. Banyard et al., 2021	Distal	-	-	-	-	M (↑ & NS)	-
2. Banyard et al., 2022	Distal	M (↑ & NS)	-	-	-	-	-
3. Blayney et al., 2021	Distal	↓	↓	↓	↓	↓	-
4. Fleming et al., 2015	Distal	-	-	-	-	-	↓
5. Haikalis et al., 2018	Distal	↓	-	-	-	-	-
6. Hust et al., 2019	Distal	-	-	-	-	-	↓
7. Intagliata 2019	Distal	-	-	-	-	-	NS
8. John et al., 2022		-	-	-	-	-	NS
9. Kaya et al., 2020	Distal	M (↑↓)	↑	M (↑↓)	M (↑↓)	M (↑↓)	-
10. Leone & Parrott, 2022	Distal	-	-	-	-	-	M (↓ & NS)
11. Leone et al., 2022	Distal	-	-	-	↑	-	-
12. Oesterle et al., 2018	Distal	↑	M (↑↓)	↑	↑	↑	-
13. Orchowski et al., 2016	Distal	-	-	-	-	-	↓
14. Orchowski et al., 2022	Distal	-	-	-	-	-	↓
15. Marcantonio et al., 2020	Distal	-	-	-	-	M (↑ ↓ & NS)	-
16. Palmer, 2016	Distal	-	-	-	-	↓	-
17. Powers et al., 2015	Distal	-	-	-	-	-	NS	-
18. Schipani-McLaughlin et al., 2020	Distal	-	-	-	-	↓	↓
19. Waterman et al., 2021	Distal	↑	-	-	-	-	-
20. Waterman et al., 2022	Distal	NS	-	-	-	-	-
21. Zozula et al., 2021	Distal	↑	-	-	-	NS	-
22. Leone & Parrott, 2019	Distal & proximal
Leone & Parrott, 2019	Distal	-	-	-	-	M (↓↑)	-
Leone & Parrott, 2019	Proximal	-	-	-	-	↓	-	Yes
23. Wiersma-Mosely et al., 2020 *	Distal & proximal	-
Wiersma-Mosely et al., 2020 *	Distal	-	↓	-	-	-	-
Wiersma-Mosely et al., 2020 *	Proximal	-	↓	-	-	-	-	Yes
24. Blayney et al., 2022	Proximal	-	-	-	-	↑	-	Yes
25. Bridges et al., 2021*	Proximal	-	↓	-	-	-	M (↓ & NS)	Yes
26. Haikalis 2018	Proximal	-	-	-	-	↓	-	Yes
27. Ham, Hurd et al., 2022*	Proximal	-	↓	NS	NS	-	-	Yes
28. Ham, Wiersma-Mosely et al., 2019*	Proximal	↓	↓	NS	NS	-	NS	Yes
29. Jozkowski et al., 2021*	Proximal	-	-	NS	-	-	-	No
30. Melkonian et al., 2020*	Proximal	↓	↓	NS	-	-	NS	Yes
31. Parrott, Swartout et al., 2020	Proximal	-	-	-	-	NS	-	No
32. Parrott, Tharp, et al., 2012	Proximal	-	-	-	-	NS	-	No

Notes. ↓ Results indicate that alcohol is a barrier to this step, relates to less endorsement of prosocial bystander behavior at this level, ↑Results indicate that alcohol can facilitate this step, M = mixed results, NS Non-significant finding, - not tested in that study.

^*Denotes studies that came from the same data collection.

^aLeone et al., (2018) theoretical model was focused on the proximal, but not distal, effects of alcohol intoxication on bystander decision making. We only compared studies that examined proximal effects of acute intoxication on bystander decision making with the theoretical model.

Across articles, Step 5 (choose to act) was the most frequently assessed bystander outcome (n = 23), followed by assessing Step 1 (notice the event; n = 10) and Step 2 (interpret the situation as risky; n = 8). Only four articles analyzed how alcohol influenced all 5 steps of the bystander decision making model; three of these articles were qualitative and one was an alcohol administration study (Blayney et al., 2021; Ham et al., 2019; Kaya et al., 2020). See Table 1 for a summary of the findings from each article related to alcohol use and the bystander decision making model.

Alcohol’s Influence on the Bystander Decision Making Model

Step 1: Notice the Event.

Ten articles assessed how alcohol use influenced noticing an event (Banyard et al., 2022; Blayney et al., 2021; Ham et al., 2019; Haikalis et al., 2018; Kaya et al., 2020; Melkonian et al., 2020; Oesterle et al., 2018; Waterman et al., 2021; Waterman et al., 2022; Zozula et al., 2021). H1 was not supported as alcohol use was negatively associated with noticing an event in only four studies. Two studies had mixed results with the findings being a combination of alcohol use positively and non-significantly relating to Step 1 (Banyard et al., 2022) or alcohol use being both positively and negatively associated with Step 1 (Kaya et al., 2020).

Across studies, eight assessed the distal effects of alcohol use on noticing the event and the results were mixed. H3A was supported as findings tended to be mixed on the relationship between the distal effects of alcohol use on Step 1. Specifically, two studies found that the distal effects of alcohol use were negatively associated with noticing the event, one found positive effects, two had mixed findings, and one had non-significant findings (See Table 1). H3B was supported for the proximal effects of alcohol use. Two studies assessed proximal effects of alcohol use on Step 1 and both found this was associated with impairments in noticing the event.

Alcohol Use Was Negatively Associated With Noticing the Event:

Results from two qualitative studies indicated that participants’ identified their own intoxication as a barrier to noticing opportunities for bystander intervention (Blayney et al., 2021; Kaya et al., 2020). A cross-sectional study of sexual assault victims inquired about the presence of bystanders and perceptions of their intoxication level, revealing that bystanders were seen as more impaired when respondents believed there was opportunity to prevent a sexual assault from happening (Haikalis et al., 2018). This increase in bystander impairment across missed opportunities for bystander intervention is consistent with alcohol as a potential barrier to noticing an opportunity for intervention.

Two studies examining the proximal effects of alcohol use also lend support for alcohol as a barrier to noticing. Ham and colleagues (2019) conducted an alcohol administration study to examine the effects of acute intoxication on recalling a vignette that involved sexual risk. The authors found that intoxicated participants recalled the story with less accuracy than no-alcohol control participants. Using a similar vignette approach in a field study, Melkonian and colleagues (2020) also found that acute intoxication related to less accuracy in assessing the intoxication of the vignette characters.

Alcohol Use Was Positively Associated With Noticing the Event:

Though most qualitative analyses highlighted alcohol as a barrier, Kaya and colleagues (2020) indicated that one participant believed that low levels of intoxication increased their awareness, thereby facilitating noticing. Further, results from two cross-sectional studies indicated that binge drinking was related to greater endorsement of witnessing bystander opportunity in both adolescents (Waterman et al., 2021) and adults (Zozula et al., 2021). Banyard and colleagues (2022) found mixed results, with alcohol use being associated with greater opportunity to witness some sexual assault situations.

Step 2: Interpret the Situation as Risky.

Eight articles assessed how alcohol influenced Step 2 of the bystander decision making model (Blayney et al., 2021; Bridges et al., 2021; Ham et al., 2022; Ham et al., 2019; Kaya et al., 2020; Oesterle et al., 2018; Melkonian et al., 2020; Wiersma-Mosley et al., 2020). Supporting H1, findings suggested that alcohol use was negatively associated with interpreting a situation as risky or concerning (n = 7), and one study had mixed results finding alcohol use was both negatively and positively associated with identification of risk.

Supporting H3A, four articles assessed distal effects of alcohol use on interpreting a situation as risky and the results were mixed; two found distal effects of alcohol use were negatively associated with risk identification, one found mixed results, and one found an increase (See Table 1). Supporting H3B, all five studies that assessed proximal effects of alcohol use on risk identification were associated with impairments at Step 2.

Alcohol Use Was Negatively Associated With Identifying Risk:

Qualitative results indicated that women reported the ambiguous nature of situations involving sexual risk as particularly challenging when drinking (Blayney et al., 2021). Heavy drinking men interviewed in focus groups further elaborated on the potential for alcohol to interfere with identifying risk. Specifically, they identified parties and bars—where sexual risk often occurs in the presence of bystanders—as risky environments where behavior that would otherwise be considered inappropriate seems commonplace (Oesterle et al., 2018).

Alcohol intoxication across two field studies was negatively associated with participants identifying a potential sexual assault victim’s discomfort in a sexual risk vignette (Ham et al., 2022; Melkonian et al., 2020); however, alcohol intoxication was not associated with participants reporting these vignettes were dangerous. Additionally, whether someone was intoxicated in an alcohol administration study was not related to perceiving risk or a need for bystander intervention (Bridges et al., 2021; Ham et al., 2019). Wiersma-Mosley and colleagues (2020) found that participants who consumed alcohol had diminished risk detection as positive alcohol valuations (i.e., the positive values we associate with alcohol use) increased, while alcohol valuations did not relate to risk detection among those in the no-alcohol control condition.

Alcohol Use Was Positively Associated With Identifying Risk:

One interviewed participant in a qualitative study reported that, if intoxicated, he would be quicker to anger in response to a situation in which he perceived someone was trying to take advantage of an intoxicated friend (Kaya et al., 2020). Heavy drinking men also reported they were attuned to overt signs of intoxication as signaling women could not consent and that they could be accused of rape if they chose to have sex with women in these situations (Oesterle et al., 2018). Thus, in unambiguous alcohol-involved sexual situations where someone is clearly intoxicated, alcohol use may facilitate assertive labeling of a situation as risky or problematic.

Step 3: Take Intervention Responsibility.

Seven articles assessed how alcohol use influenced participants ability to take intervention responsibility (Blayney et al., 2021; Ham et al., 2022; Ham et al., 2019; Jozkowski et al., 2021; Kaya et al., 2020; Melkonian et al., 2020; Oesterle et al., 2018). H1 was not supported for Step 3. Nearly half of the studies (n = 4) found no relationship between alcohol use and taking intervention responsibility.

Supporting H3A, three studies assessed the distal effects of alcohol use on taking responsibility; one found alcohol use was negatively associated with responsibility, one had mixed findings, and one found it was associated with an increase in responsibility (See Table 1). Across studies which assessed proximal effects of alcohol use on taking perceived responsibility, H3B was not supported as alcohol use was consistently not related to this step (Ham et al., 2019, 2022; Jozkowski et al., 2021; Melkonian et al., 2020). However, across these four studies, two came from one data collection (Ham et al., 2019; Jozkowski et al., 2021) and another two came from the same data collection (Ham et al., 2022; Melkonian et al., 2020).

Alcohol Use Was Negatively Associated With Taking Responsibility:

Women interviewed in focus groups identified a “mom role,” that is assumed by women who typically drink less (Blayney et al., 2021). A mom role entailed one person in a friend group taking greater responsibility in assessing risk, making decisions for the group, and getting friends home safely. College men also reported a greater sense of responsibility when sober among a group of intoxicated peers and reported that in organizations, such as fraternities, a sober monitor role is often designated (Kaya et al., 2020).

Alcohol Use Was Positively Associated With Taking Responsibility:

In addition to reporting that, generally, being less intoxicated or sober contributes to increased responsibility, college men also reported that they may be more likely to take bystander responsibility when intoxicated as a demonstration of masculinity (Oesterle et al., 2018).

Step 4: Decide How to Help.

Six articles assessed how alcohol use influenced deciding to help (Blayney et al., 2021; Kaya et al., 2020; Leone et al., 2022; Ham et al., 2022; Ham et al. 2019; Oesterle et al., 2018). Partially supporting H1 and H2, we found that alcohol use had both negative (H1) and positive (H2) relationships with Step 4. One study found alcohol operates as a barrier, two found alcohol may be positively related to decisions to intervene, one had mixed results, and two yielded non-significant results.

H3A was partially supported; four studies that assessed the distal effects of alcohol use on deciding to help had mixed findings. One study found alcohol use was associated with a decrease in Step 4; two found it was associated with an increase in Step 4, and one had mixed findings. H3B was not supported as the proximal effects of alcohol use did not relate to Step 4. Specifically, the proximal effects of alcohol use did not relate to ratings of pros and cons of potential intervention strategies (Ham et al., 2019) or confidence to intervene (Ham et al., 2022).

Alcohol Use Was Negatively Associated With Deciding How to Intervene:

College women described intoxication as sometimes resulting in being “too drunk to function,” which would impair their ability to plan an intervention strategy (Blayney at al., 2021). Qualitative results also identified that specific strategies, such as coordinating intervention with friends, would be easier to do when sober (Kaya et al., 2020).

Alcohol Use Was Positively Associated With Deciding How to Intervene:

While participants acknowledge that significant intoxication is largely a barrier to deciding how to intervene, some participants reported they just needed to be “sober enough” to intervene (Kaya et al., 2020). Additionally, a cross-sectional study found that participants reported increased self-efficacy to bystand as their alcohol consumption frequency also increased (Leone et al., 2022). In a qualitative study with heavy drinking men, some participants reported that alcohol provided them the liquid courage to intervene (Oesterle et al., 2018).

Step 5: Choose to Act.

Twenty-three articles assessed how alcohol use influenced choosing to act. Within these 23 articles, 14 studies examined bystander behavior (via self-report or observation), and 12 studies examined bystander intentions to act (see Table 1). Across these articles, H1 and H2 were partially supported as there were both negative and positive effects of alcohol use on Step 5. Nine studies found that alcohol use was negatively associated with intervention or intention to act (one study did assess both bystander behavior and intention; Schipani-McLaughlin et al., 2020). Eight studies found no relationship between alcohol use and choosing to act. Six found mixed findings and two studies found alcohol use was positively associated with bystander intervention.

H3A was supported. Researchers accounted for the distal effects of alcohol use in 17 articles, with mixed findings. Seven studies found that alcohol use was negatively associated with this step, four found mixed effects. H3B was not supported. Researchers accounted for the proximal effects of alcohol use in seven articles and overall, findings were non-significant.

Alcohol Use Was Negatively Associated With Bystander Intervention or Intention to Act:

Qualitative results indicated that college students perceived intoxication as being likely to interfere with one’s ability to execute bystander intervention (Blayney et al., 2021; Kaya et al., 2020). Across almost all correlational studies, alcohol use related to less bystander behavior and bystander intentions (Fleming & Wiersma-Mosley, 2015; Hust et al., 2019; Orchowski et al., 2016; Palmer, 2016; Powers et al., 2015; Schipani-McLaughlin et al., 2020). In one exception, binge drinking did not relate to bystander intervention in situations involving sexual coercion (Zozula et al., 2021). In an alcohol administration study, sober participants were more likely to state intentions to help a potential victim in a sexual risk scenario than were intoxicated participants (Bridges et al., 2021).

Alcohol Use Was Positively Associated With Bystander Intervention or Intention to Act:

Qualitative research revealed that some participants viewed themselves as exceptions, who believed alcohol would not impair their intervention efforts (Blayney et al., 2020). Again, “liquid courage” was perceived to increase the likelihood of direct confrontation and physically aggressive bystander intervention by heavy drinking college men (Oesterle et al., 2018).

Leone and Parrott (2019) examined the association between heavy episodic drinking and intervention behavior to stop a sexual video in a laboratory analogue task. Heavy episodic drinkers were more likely to intervene, but among all who intervened, they were slower to act than non-heavy episodic drinkers. This study also used an alcohol manipulation to examine the impact of acute alcohol intoxication. Though there was not a main effect of alcohol condition, results indicated that intoxication decreased men’s likelihood of bystander intervention among those with higher bystander intentions. An additional five alcohol administration studies and one field study yielded null findings when examining the impact of bystander alcohol intoxication on bystander intervention or intentions (Bridges et al., 2021; Ham, Wiersma-Mosley et al., 2019; Haikalis, 2018; Melkonian et al., 2020; Parrot et al., 2020; Parrot et al., 2012).

Discussion

The goal of this study was to conduct a systematic literature review of research on how alcohol use influences the bystander decision making model. Our review included 32 articles published from 2015-2022 that used various methodologies (e.g., cross sectional, alcohol administration, interviews) to assess how alcohol use could impede or facilitate bystander decision making. Across these studies, we found mixed support that alcohol use was negatively associated with bystander decision making (partially supporting H1). Specifically, at Step 1, four of ten articles (40.0%) found that alcohol use or intoxication was negatively associated with noticing potential bystander opportunities. At Step 2, seven of eight (87.5%) articles found that alcohol use or intoxication was negatively associated with risk identification. At Step 3, only one of seven articles (14.2%) found that alcohol use was negatively associated with impairments in responsibility; the majority found non-significant findings. At Step 4, only one of six articles (16.6%) found that alcohol use associated with impairments in deciding to act. At Step 5, nine of 23 studies (39.1%) found that alcohol use or intoxication was negatively associated with intervention and five additional studies had mixed findings that included alcohol use being associated with impairments in bystander behaviors or intentions. Collectively, 14 studies (60.8%) found that alcohol use was negatively associated with bystander intervention behaviors or intention.

Across a few studies researchers’ found that alcohol use or intoxication could facilitate bystander decision making at Step 4 or 5 of the model being assessed (supporting for H2). We also found that when researchers assessed the distal effects of alcohol use on bystander decision making, the results were more often mixed with distal alcohol use being positively, negatively, or having no relationship with bystander decision making (supporting H3A). For proximal effects, alcohol intoxication was consistently associated with impairments in bystander decision making at Step 1 and Step 2. We review our findings below and discuss why alcohol use may facilitate or impede bystander intervention at each step.

Alcohol Use and Bystander Decision Making

In Step 1 and Step 2, alcohol use was negatively associated with noticing an event and interpreting an event as risky (See Table 1). Specifically, alcohol use appeared to increase the likelihood that people could become easily distracted or miss cues (Ham et al., 2019; Melkonian et al., 2020). Further, alcohol use may have impacted someone’s ability to identify discomfort or recognize a situation as risky (Bridges et al., 2020). Alcohol’s impact on Step 1 and Step 2 of the bystander decision making model may occur because of alcohol myopia (Leone et al., 2018; Steele & Josephs, 1990). Specifically, when people are drinking or intoxicated, they focus on situations that are salient to them, such as having a good time at a party with friends, rather than looking for potential sexual assault situations to intervene on. Alcohol use can also impair people’s judgement when it comes to identifying discomfort, perhaps due to the relaxation or sedative effects of alcohol on the body (Sayette, 1999) which could increase people’s perceptions that everyone is having fun or a good time and decrease recognition of risk; this reflects the theoretical framework proposed by Leone and colleagues (2018).

Yet, in a few studies, alcohol use was positively associated with noticing an event and risk (Banyard et al., 2021; Kaya et al., 2020; Oesterle et al., 2018; Waterman et al., 2021; Zozula et al., 2021). Alcohol use may be positively associated with noticing an event or risk because people who are consuming alcohol may be at a greater likelihood to be in settings where sexual assault risk is present (e.g., bars/parties). Thus, there is a greater opportunity to witness potential sexual assault risk factors. Additionally, people have become more aware that alcohol use is a risk factor for sexual assault victimization due to several initiatives at the federal (White House Task Force), state (Affirmative Consent Policies), and school/college campus level (Bringing in the Bystander; Green Dot). In line with alcohol myopia theory, this risk may be a salient cue in drinking settings leading individuals to have a heightened awareness for risky situations when intoxicated. In other words, awareness of sexual assault as a problem may moderate the effects of acute alcohol intoxication or alcohol use on noticing; however, more research is needed to confirm this hypothesis.

Within Step 3, nearly half the findings from studies did not find a relationship between alcohol use and taking responsibility (see Table 1). These null results related to Step 3 of the bystander decision making model may occur because the idea of taking responsibility within a sexual assault situation is a pivotal shift in thinking by a bystander. Stated differently, by arriving at the stage of taking responsibility, people may have noticed an event and interpreted that event as risky. Because they have gone through these first two steps, the effects of alcohol use on impeding their ability to take responsibility may become less impactful. Contrary to this idea, Step 3 may be difficult to assess in quantitative work, which most of the studies included in this review are, because there could be a degree of priming or social desirability that occurs for the participant. For instance, in asking someone how responsible they feel to act in sexual assault situation, researchers have inherently suggested there is something for participants to potentially feel responsible about. Therefore, participants may report that they would take responsibility because that is the socially acceptable response. Given these mixed findings and methodological challenges with assessing this step, we are unsure if the prior work supports the theoretical model proposed by Leone and colleagues (2018).

Finally, for Step 4 and 5, alcohol use did appear to have some negative effects on deciding to act and choosing to act. Within Step 4, there appeared to be a uni-curve effect where some alcohol consumption could increase people’s courage and decreases apprehension over intervening. Therefore, consuming some alcohol could be associated with greater confidence to act in a situation. However, consuming too much alcohol meant people may be unable to properly plan or think through a situation and thus bystand—in line with the pharmacological effects of alcohol on executive cognitive functioning (Leone et al., 2018; Steele & Josephs, 1990). Further illustrating how alcohol use impacts executive cognitive functioning, alcohol use was also associated with a decreased ability to engage in effective bystander intervention behaviors (see Table 1). Because alcohol can impair our ability to plan and execute complex behaviors, intervention strategies may become more simple but also aggressive (e.g., pushing someone). Thus, alcohol use could result in more aggressive intervention styles (Bridges et al., 2021; Parks et al., 2013; Oesterle et al., 2018), further exacerbating a potential sexual assault situation and increasing the risk of harm to the bystander as well. Taken together, some of the research focused on examining proximal effects of alcohol intoxication on Step 4 and 5 support Leone and colleagues (2018) theoretical model.

Limitations and Future Directions

There are several limitations to our review. First, this is a systematic review and not a meta-analysis, which limits our ability to discuss the magnitude of the effects of alcohol on bystander decision making. Second, across these samples, the participants were primarily White, heterosexual, cisgender, and college attending students. There is a need to diversify who is included in bystander and sexual violence research—especially given that women of color and sexual and gender minority persons are at greater risk to experience sexual violence compared with their White, heterosexual, cisgender counterparts (Armstrong et al., 2018; Ford & Soto-Marquez, 2016; Hequembourg et al., 2015, 2015; Rothman et al., 2011).

Third, how alcohol use was assessed across these studies varied, with some assessing the distal effects of alcohol use such as typical drinking, binge drinking, frequency of drinking, and others assessing the proximal effects of alcohol, through alcohol administration, or using field-based methodologies. Moving forward, researchers may want to consider what type of alcohol behaviors are most likely to be associated with bystander decision making and focus on assessing these to inform larger interventions. For instance, researchers may want to focus on alcohol consumed prior to witnessing a sexual assault situation rather than typical use as this may provide greater insight into how alcohol could facilitate or impede bystander intervention. More work with alcohol administration and bystander decision making is also warranted to further understand how acute intoxication impairs the bystander decision making model.

Fourth, the bystander decision making model was measured in a variety of ways—some researchers provided participants with vignettes, others asked them to recall situations in their own lives, and some presented them with opportunities to intervene. Given challenges with recall bias in bystander situations, having diverse methodologies to assess this bystander decision making and behavior is helpful and increases researchers’ ability to understand how this may look in the moment. However, many of these methodologies are rather controlled—people are not distracted by the environment surrounding them. People are also not being presented with social norms that may prevent intervention. Moving forward, developing methodologies which create more realistic environments where people have opportunities to bystand may be warranted—such as using virtual reality.

Fifth, the questions used to elicit responses about bystander decision making varied across studies. For instance, for Step 1, noticing an event, some researchers had participants listen to a vignette and then recall the story they listened to, and others asked participants to recall a situation. While both these questions can represent Step 1, they are starkly different. Future researchers may want to develop a set of validated items which assess the bystander decision making model so that larger conclusions could be drawn from the findings Additionally, while the bystander decision making-model is conceptualized to be an iterative, non-linear process—researchers assess this process linearly in surveys (e.g., did you notice, did you take responsibility). Moving forward, qualitative methodologies may assist with understanding the non-linear, iterative process of bystander decision making and how people weigh the choice to intervene when alcohol is involved.

Sixth, in thinking about the future of bystander research and assessment of the bystander decision making model, researchers may want to consider more advanced methodological approaches to assess how alcohol use impacts bystander decision making. For instance, several studies found no relationship between alcohol use and Step 3 of the model; however, one may be less likely to take responsibility to act if others are present. Thus, researchers could develop virtual reality scenarios that vary the number of people present during a sexual assault situation to assess how alcohol use, in the presences of others who may or may not be intoxicated, could impact someone’s choice to take responsibility. Additionally, moving towards ecological momentary assessments where participants can report on how intoxicated they and others are around them are, their bystander behaviors, and experiences with sexual assault victimization may provide further information on if, when, where, and how people are acting. Indeed, Blayney and colleagues (2022) implemented this research design and were able to assess how intoxication level of both the participant and their friends related to bystander behaviors.

Seventh, while not a limitation, bystander research should continue to assess multiple perspectives during potential sexual assault situations to inform future research. For instance, Haikalis and colleagues (2018) assessed the victim’s perspectives of intoxicated bystanders around them. Whereas other studies focused on the bystander’s perspective while intoxicated. Both viewpoints are necessary to understand when people intervene and the missed opportunities to act. Moving forward, researchers should continue to assess multiple people’s perspective on intervention to provide further information to bystander intervention programs on how to increase prosocial bystander decision making.

Finally, sexual assault research, broadly, is stemming away from whether alcohol increases the risk of sexual assault occurring and instead focusing for whom and in what situations alcohol use may increase that risk (Parrott & Eckhardt, 2018). Bystander researchers may also want to follow this path and examine how alcohol use, in combination with other factors, could impede or facilitate bystander decision making. A few studies in our review did examine additional individual level factors (e.g., intent to help, alcohol expectancies; Bridges et al., 2020; Hust et al., 2019; Leone & Parrott, 2019; Marcantonio et al., 2020; Wiersma-Mosley et al., 2020); however, additional work is needed in this area to inform intervention efforts. The lack of research examining additional factors associated with alcohol use and bystander decision making makes sense given the infancy of this work. As the field continues to understand when and how alcohol use impacts bystander decision making, we can continue to examine how additional factors moderate or mediate this relationship.

Prevention Implications

Although our study has some limitations, our findings provide important insights into how alcohol use is related to bystander decision making and provides implications for prevention programs (see Table 2). Alcohol use can have a negative impact on bystander decision making. Therefore, bystander intervention programs should consider incorporating information about how alcohol affects a person’s ability to act as a helpful bystander. Rather than solely framing alcohol as a risk factor for sexual assault victimization and perpetration, these programs could expand their narrative to include the impairment of bystander’s ability to recognize risky situations when alcohol is involved. Subsequently, prevention programs can discuss strategies to address this limitation, such as having a friend who consumes less alcohol at a party or remaining sober. Additionally, promoting ongoing and open communication among young people during drinking experiences, including checking in with each other, may prove valuable. This is particularly important because alcohol appears to hinder the initial stages of the bystander decision-making process and maintaining open lines of communication could help overcome this obstacle. Recognizing that alcohol can impair complex decision making, bystander intervention programs might consider providing people with simple yet effective bystander strategies that can be implemented event when intoxicated (Bridges et al., 2021). Finally, sexual assault prevention programs that focus on bystander intervention may benefit from training young people who frequently attend alcohol-intensive environments, such as bars or parties. These settings carry an elevated risk of sexual assault, offering more opportunities for young people to prevent such incidents through bystander action.

Table 2.

Implications for Practice and Research

Practice    • This review provides bystander intervention programs with a summary of the available research on how alcohol use may relate to bystander decision making.    • Bystander intervention programs may want to expand their discussions with people to include a component on how alcohol use could impede participants ability to effectively intervene.    • Bystander intervention programs may want to train participants in their programs on simple and effective strategies that could be implemented if someone was intoxicated.    • Bystander intervention programs should be mindful that the current research does not acknowledge or assess how power differentials that exist between and within people could influence how alcohol use relates to bystander decision making.

Research    • Across 32 studies, the populations comprised dominant identities (e.g., White, cisgender, heterosexual) and more research is needed to examine how alcohol use relates to the bystander decision making model outside of these identities to inform culturally sensitive and inclusive bystander intervention programs.    • Alcohol use was assessed through different questionnaires and methodology, making cross-study comparisons challenging and limiting generalizability.    • Bystander decision making was assessed through different methodologies and questionnaires, which creates challenges for comparisons across studies.    • How alcohol use in combination with other factors (such as gender, personality traits, bystander contextual factors) was rarely assessed and needed to further understand how alcohol use may impede or facilitate bystander intervention.

Appendix I.

Database: Ovid MEDLINE(R) and Epub Ahead of Print, In-Process, In-Data-Review & Other Non-Indexed Citations, Daily and Versions(R) <1946 to July 01, 2021>

Date Run: July 02, 2021

Results: 2745

Search Strategy:

--------------------------------------------------------------------------------

1 sex offenses/ or rape/ (15091)

2 sexual behavior/ or Sexism/ or Sex Factors/ (330388)

3 Aggression/ or Coercion/ or Violence/ (66792)

4 2 and 3 (5403)

5 Gender-Based Violence/ (314)

6 (grope* or groping).ti,ab,kf. (187)

7 ((sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*)).ti,ab,kf. (82256)

8 (sexual* adj3 aggress*).ti,ab,kf. (1745)

9 (rape or raped or rapes or rapist*).ti,ab,kf. (8907)

10 1 or 4 or 5 or 6 or 7 or 8 or 9 (97469)

11 exp Alcohol Drinking/ (72154)

12 exp Alcoholic Beverages/ (21348)

13 exp Alcohol-Related Disorders/ (115607)

14 ethanol/ or blood alcohol content/ (89871)

15 (alcohol or alcohol-induced or alcohol-facilitated or alcohols or alcoholic or alcoholism).ti,ab,kf. (352579)

16 (beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka).ti,ab,kf. (160797)

17 (drink* adj3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical)).ti,ab,kf. (19221)

18 (drunk* or inebriate* or tipsy).ti,ab,kf. (4854)

19 intoxicat*.ti,ab,kf. (48794)

20 (bar or bars or frat* or nightclub* or night club* or party or parties or sororit*).ti,ab,kf. (68885)

21 or/11-20 (631865)

22 altruism/ or cooperative behavior/ or helping behavior/ (53917)

23 exp Social Responsibility/ (24346)

24 (bystander* or onlooker* or third party or witness*).ti,ab,kf. (49040)

25 (assist* or help* or interven* or prevent* or stop*).ti,ab,kf. (3682224)

26 or/22-25 (3779182)

27 10 and 21 and 26 (2891)

28 (exp animals/ or exp animal experimentation/ or exp models, animal/) not humans/ (4856988)

29 27 not 28 (2875)

30 limit 29 to english language (2756)

31 remove duplicates from 30 (2745)

32 (“22549741” or “31014471” or “30500086” or “30505616” or “31140371” or “25944836” or “30623745” or “30908129” or “30466362” or “32672105” or “26175516” or “30037317” or “33151846” or “31315505” or “33336612” or “32416362”).ui. (16)

33 31 and 32 (16)

Database: SocINDEX (via EBSCO)

Date Run: July 02, 2021

Results: 1439

Search Strategy:

--------------------------------------------------------------------------------

S26 S9 AND S19 AND S25 (1,439)

S25 S20 OR S21 OR S22 OR S23 OR S24 (356,162)

S24 TI ( assist* or help* or interven* or prevent* or stop* ) OR AB ( assist* or help* or interven* or prevent* or stop* ) OR KW ( assist* or help* or interven* or prevent* or stop* ) (337,108)

S23 TI ( bystander* or onlooker* or “third party” or witness* ) OR AB ( bystander* or onlooker* or “third party” or witness* ) OR KW ( bystander* or onlooker* or “third party” or witness* ) (20,699)

S22 DE “PREVENTION of sexual assault” OR DE “ANTI-rape movement” OR DE “RAPE prevention” (231)

S21 DE “SOCIAL responsibility” (1,383)

S20 (DE “HELPING behavior” OR DE “BYSTANDER effect (Psychology)” OR DE “BYSTANDER involvement” OR DE “ALTRUISM” OR DE “PROSOCIAL behavior”) OR (DE “COOPERATIVENESS”) (4,825)

S19 S10 OR S11 OR S12 OR S13 OR S14 OR S15 OR S16 OR S17 OR S18 (123,798)

S18 TI ( bar or bars or frat* or nightclub* or night club* or party or parties or sororit* ) OR AB ( bar or bars or frat* or nightclub* or night club* or party or parties or sororit* ) OR KW ( bar or bars or frat* or nightclub* or night club* or party or parties or sororit* ) (58,553)

S17 TI intoxicat* OR AB intoxicat* OR KW intoxicat* (3,322)

S16 TI ( drunk* or inebriate* or tipsy ) OR AB ( drunk* or inebriate* or tipsy ) OR KW ( drunk* or inebriate* or tipsy ) (4,232)

S15 TI ( drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) OR AB ( drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) OR KW ( drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) (5,062)

S14 TI ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka ) OR AB ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka ) OR KW ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka ) (5,820)

S13 TI ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism ) OR AB ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism ) OR KW ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism ) (58,163)

S12 DE “DRUNKENNESS (Criminal law)” OR DE “YOUNG adults -- Alcohol use” OR DE “ALCOHOLIC intoxication” OR DE “ALCOHOLICS” OR DE “ALCOHOLISM” OR DE “ALCOHOLISM & crime” OR DE “TEMPERANCE” (15,248)

S11 DE “ALCOHOLIC beverages” OR DE “NIGHTCLUBS” OR DE “BARS (Drinking establishments)” (1,894)

S10 DE “ALCOHOL drinking” OR DE “BINGE drinking” OR DE “CONTROLLED drinking” OR DE “DRUG addicts -- Alcohol use” OR DE “LGBTQ+ people -- Alcohol use” OR DE “STUDENTS -- Alcohol use” OR DE “ALCOHOL drinking -- Social aspects” (8,239)

S9 S1 OR S4 OR S5 OR S6 OR S7 OR S8 (43,217)

S8 TI ( rape or raped or rapes or rapist* ) OR AB ( rape or raped or rapes or rapist* ) OR KW ( rape or raped or rapes or rapist* ) (11,453)

S7 TI (sexual* N3 aggress*) OR AB (sexual* N3 aggress*) OR KW (sexual* N3 aggress*) (1,084)

S6 TI ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) ) OR AB ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) ) OR KW ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) ) (34,259)

S5 TI ( grope* or groping ) OR AB ( grope* or groping ) OR KW ( grope* or groping ) (143)

S4 S2 AND S3 (7)

S3 (DE “AGGRESSION (Psychology)”) AND (DE “VIOLENCE” OR DE “VIOLENCE against women” OR DE “OFFENSES against the person”) (603)

S2 (DE “INSTITUTIONALIZED persons’ sexual behavior” OR DE “LGBTQ people’s sexual behavior” OR DE “MEN’S sexual behavior” OR DE “OLDER people’s sexual behavior” OR DE “SEXUAL behavior of people with disabilities” OR DE “COLLEGE students’ sexual behavior” OR DE “YOUNG adults’ sexual behavior” OR DE “YOUTHS’ sexual behavior”) OR (DE “GENDER differences (Sociology)” OR DE “SEXISM”) (4,448)

S1 DE “RAPE” OR DE “MALE rape” OR DE “RAPE in marriage” OR DE “RAPE in the military” OR DE “METOO movement” OR DE “SEXUAL assault” OR DE “SEXUAL aggression” OR DE “SEXUAL abuse victims” OR DE “LGBTQ rape victims” OR DE “MALE sexual abuse victims” OR DE “RAPE victims” OR DE “SEX crimes” (12,955)

Database: Gender Studies Database (via EBSCO)

Date Run: July 02, 2021

Results: 523

Search Strategy:

--------------------------------------------------------------------------------

S24 S6 AND S17 AND S23 (523) Limiters - Language: English

S23 S18 OR S19 OR S20 OR S21 OR S22 (103,783)

S22 TI ( assist* or help* or interven* or prevent* or stop* ) OR AB ( assist* or help* or interven* or prevent* or stop* ) OR KW ( assist* or help* or interven* or prevent* or stop* ) (99,646)

S21 TI ( bystander* or onlooker* or “third party” or witness* ) OR AB ( bystander* or onlooker* or “third party” or witness* ) OR KW ( bystander* or onlooker* or “third party” or witness* ) (3,339)

S20 (ZU “sexual assault -- prevention -- law & legislation”) or (ZU “rape prevention”) (87)

S19 (ZU “social responsibility”) or (ZU “prosocial behavior”) or (ZU “prosocial behavior -- research”) or (ZU “bystander effect”) or (ZU “bystander effect (psychology)”) or (ZU “bystander involvement”) (756)

S18 (ZU “altruism”) or (ZU “cooperation”) or (ZU “helping behavior”) or (ZU “helping behavior -- research”) (1,383)

S17 S7 OR S8 OR S9 OR S10 OR S11 OR S12 OR S13 OR S14 OR S15 OR S16 (20,766)

S16 TI ( bar or bars or frat* or nightclub* or “night club*” or party or parties or sororit* ) OR AB ( bar or bars or frat* or nightclub* or “night club*” or party or parties or sororit* ) OR KW ( bar or bars or frat* or nightclub* or “night club*” or party or parties or sororit* ) (11,335)

S15 TI intoxicat* OR AB intoxicat* OR KW intoxicat* (312)

S14 TI ( drunk* or inebriate* or tipsy ) OR AB ( drunk* or inebriate* or tipsy ) OR KW ( drunk* or inebriate* or tipsy ) (327)

S13 TI ( (drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) OR AB ( (drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) OR KW ( (drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) (627)

S12 TI ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka ) OR AB ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka ) OR KW ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka ) (1,095)

S11 TI ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism ) OR AB ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism ) OR KW ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism ) (7,657)

S10 (ZU “ethanol”) or (ZU “blood alcohol”) or (ZU “blood alcohol -- analysis”) or (ZU “blood alcohol analysis”) (47)

S9 (ZU “alcoholism”) or (ZU “alcoholism & crime”) or (ZU “alcoholism -- research”) or (ZU “alcoholism -- social aspects”) or (ZU “alcoholic fathers”) or (ZU “alcoholic intoxication”) or (ZU “alcoholics”) or (ZU “alcoholics -- research”) or (ZU “alcoholic intoxication”) or (ZU “alcoholic psychoses”) (2,157)

S8 ((ZU “alcoholic beverages”) or (ZU “alcoholic beverages -- research”) or (ZU “alcoholic beverages -- social aspects”) or (ZU “alcoholic beverages -- therapeutic use”) or (ZU “wine & wine making”)) or ((ZU “beer”) or (ZU “whiskey”) or (ZU “tequila”) or (ZU “rum”) or (ZU “liquors”)) (189)

S7 (((ZU “alcohol drinking”) or (ZU “alcohol drinking -- health aspects”) or (ZU “alcohol drinking -- risk factors”) or (ZU “alcohol drinking -- social aspects”) or (ZU “alcohol drinking -- united states”) or (ZU “alcohol in the body”)) or ((ZU “binge drinking”) or (ZU “binge drinking -- research”))) or ((ZU “controlled drinking”)) (636)

S6 S1 OR S2 OR S3 OR S4 OR S5 (29,451)

S5 TI ( rape or raped or rapes or rapist* ) OR AB ( rape or raped or rapes or rapist* ) OR KW ( rape or raped or rapes or rapist* ) (9,553)

S4 TI (sexual* N3 aggress*) OR AB (sexual* N3 aggress*) OR KW (sexual* N3 aggress*) (764)

S3 TI ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) ) OR AB ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) ) OR KW ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) ) (21,687)

S2 TI ( grope* or groping ) OR AB ( grope* or groping ) OR KW ( grope* or groping ) (45)

S1 ((ZU “sexual assault”) or (ZU “sexual assault -- social aspects”)) or ((ZU “rape”) or (ZU “rape -- social aspects”) or (ZU “rape -- united states”) or (ZU “rape -- universities & colleges”)) OR (ZU “sexual aggression”) (5,796)

Database:

Web of Science Core Collection

• Science Citation Index Expanded (SCI-EXPANDED) --1900-present

• Social Sciences Citation Index (SSCI) --1900-present

• Arts & Humanities Citation Index (A&HCI) --1975-present

• Emerging Sources Citation Index (ESCI) --2015-present

Date Run: July 02, 2021

Results: 4035

Search Strategy:

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# 18 (#16 NOT #17) AND LANGUAGE: (English) 4,035

# 17 TS((animal* OR canine* OR dog OR dogs OR feline OR hamster OR lamb OR lambs OR mice OR monkey OR monkeys OR mouse OR murine OR pig OR pigs OR piglet* OR porcine OR primate* OR rabbit* OR rat OR rats OR rodent* OR sheep*) NOT (human* OR patient*) ) 4,016,856

# 16 #15 AND #12 AND #5 4,245

# 15 #14 OR #13 4,870,920

# 14 TOPIC: (assist* or help* or interven* or prevent* or stop*) 4,792,423

# 13 TS(bystander* or onlooker* or ”third party” or witness*) 97,877

# 12 #11 OR #10 OR #9 OR #8 OR #7 OR #6 1,422,002

# 11 TOPIC: (bar or bars or frat* or nightclub* or “night club*” or party or parties or sororit*) 457,893

# 10 TOPIC: (intoxicat*) 50,816

# 9 TOPIC: (drunk* or inebriate* or tipsy) 6,338

# 8 TS(drink* NEAR/3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) 27,825

# 7 TOPIC: (beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka) 375,791

# 6 TS(alcohol or ”alcohol-induced” or ”alcohol-facilitated” or alcohols or alcoholic or alcoholism) 621,204

# 5 #4 OR #3 OR #2 OR #1 149,458

# 4 TOPIC: (rape or raped or rapes or rapist*) 28,321

# 3 TS(sexual* NEAR/3 aggress*) 3,040

# 2 TOPIC: (sex OR sexual*) AND TOPIC: (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) 127,653

# 1 TS(grope* OR groping) 567

Database: APA PsycInfo (via EBSCO)

Date Run: August 24, 2021

Results: 2668

Search Strategy:

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S27 S26 NOT (PO Animal NOT PO Human) (2,668)

Limiters - Published Date: −20210731; Language: English

S26 S9 AND S20 AND S25

S25 S21 OR S22 OR S23 OR S24

S24 TI ( assist* or help* or interven* or prevent* or stop* ) OR AB ( assist* or help* or interven* or prevent* or stop* ) OR KW ( assist* or help* or interven* or prevent* or stop* )

S23 TI ( bystander* or onlooker* or “third party” or witness* ) OR AB ( bystander* or onlooker* or “third party” or witness* ) OR KW ( bystander* or onlooker* or “third party” or witness* )

S22 DE “Social Responsibility” OR DE “Responsibility”

S21 (DE “Assistance (Social Behavior)” OR DE “Bystander Effect” OR DE “Social Support” OR DE “Prosocial Behavior” OR DE “Altruism” OR DE “Charitable Behavior” OR DE “Cooperation” OR DE “Heroes” OR DE “Kindness”) OR (DE “Cooperation”)

S20 S10 OR S11 OR S12 OR S13 OR S14 OR S15 OR S16 OR S17 OR S18 OR S19

S19 TI ( bar or bars or frat* or nightclub* or “night club*” or party or parties or sororit* ) OR AB ( bar or bars or frat* or nightclub* or “night club*” or party or parties or sororit* ) OR KW ( bar or bars or frat* or nightclub* or “night club*” or party or parties or sororit* )

S18 TI intoxicat* OR AB intoxicat* OR KW intoxicat*

S17 TI ( drunk* or inebriate* or tipsy ) OR AB ( drunk* or inebriate* or tipsy ) OR KW ( drunk* or inebriate* or tipsy )

S16 TI ( drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) OR AB ( drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) ) OR KW ( drink* N3 (binge* or context or contexts or heavy or heavily or norm or norms or social or standard or typical) )

S15 TI ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka ) OR AB ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka ) OR KW ( beer or beers or ethanol or liquor* or rum or whiskey or wine or wines or tequila or vodka )

S14 TI ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism ) OR AB ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism ) OR KW ( alcohol or “alcohol-induced” or “alcohol-facilitated” or alcohols or alcoholic or alcoholism )

S13 (DE “Ethanol”) OR (DE “Blood Alcohol Concentration”)

S12 (DE “Alcoholic Psychosis” OR DE “Alcoholic Hallucinosis” OR DE “Alcoholism” OR DE “Alcohol Use Disorder” OR DE “Alcohol Abuse” OR DE “Alcohol Intoxication” OR DE “Alcohol Withdrawal” OR DE “Korsakoffs Psychosis” OR DE “Wernicke’s Syndrome” OR DE “Alcohol Intoxication” OR DE “Acute Alcoholic Intoxication” OR DE “Chronic Alcoholic Intoxication”) OR (DE “Delirium Tremens”)

S11 DE “Alcoholic Beverages” OR DE “Beer” OR DE “Liquor” OR DE “Wine”

S10 DE “Alcohol Drinking Patterns” OR DE “Binge Drinking” OR DE “Social Drinking” OR DE “Underage Drinking”

S9 S1 OR S4 OR S5 OR S6 OR S7 OR S8

S8 TI ( rape or raped or rapes or rapist* ) OR AB ( rape or raped or rapes or rapist* ) OR KW ( rape or raped or rapes or rapist* )

S7 TI (sexual* N3 aggress*) OR AB (sexual* N3 aggress*) OR KW (sexual* N3 aggress*)

S6 TI ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) ) OR AB ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) ) OR KW ( (sex or sexual*) and (assault* or coerci* or consent* or consensual or nonconsensual or offender* or offense* or perpetrat* or surviv* or victim* or violat* or violen*) )

S5 TI ( grope* or groping ) OR AB ( grope* or groping ) OR KW ( grope* or groping )

S4 S2 AND S3

S3 (DE “Aggressiveness” OR DE “Aggressive Behavior” OR DE “Coercion”) OR (DE “Violence”)

S2 ((DE “Psychosexual Behavior”) OR (DE “Sexism”)) OR (DE “Human Sex Differences”)

S1 DE “Sex Offenses” OR DE “Sexual Abuse” OR DE “Rape” OR DE “Acquaintance Rape” OR DE “Sexual Abuse”

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