Table 1.
Health-related studies on inoculation theory.
| Health topic | Study | Participants | Methods | Primary findings |
|---|---|---|---|---|
| Alcohol consumption | Godbold and Pfau, 2000 | 417 sixth graders (mean age = 11.2 years) from seven middle schools, USA | 3 (message type: normative inoculation, informational inoculation, neutral noninoculative) × 2 (attack timing: immediate, after 2 weeks) | Exposure to the normative message was associated with significantly lower estimations of peer acceptance of alcohol use when compared to the informational and control conditions. The normative message was also superior in attitude maintenance from Time 1 to Time 3 (4 weeks later). Participants receiving an attack immediately after an inoculation message were less persuaded by the attack compared to those who had received a delay between inoculation and attack |
| Binge drinking | Richards and Banas, 2015 | 275 students at a large Mid-Atlantic university, USA | Inoculation condition compared with control; Structural equation modeling to test relationships between inoculation, threat to freedom, reactance, and intentions to drink | Inoculation messages can reduce psychological reactance |
| Binge drinking (and marijuana use) | Cornelis et al., 2013 | 156 students in three secondary schools in Belgium | Issue ambivalence moderated message effectiveness | |
| Commercial food advertising (health- and nutrition-related claims) | Mason and Miller, 2013 | 145 students in Midwestern university, USA | Experiment with predictor variables of treatment/control, positive/negative outcome focus, and concrete/abstract linguistic signature of message | Inoculation messages led to resistance to deceptive health- and nutrition-related commercial food claims |
| Frequency of doctor visitation | McGuire, 1961a | 168 students enrolled in introductory psychology course at the University of Illinois | 2 (experimental condition: refutational/nonrefutational) × 2 (experimental condition: ambivalent/nonambivalent) Eight restoration conditions varying in refutational and supportive elements, and six control conditions | Issues were collapsed for analyses. No conclusions drawn about health topic |
| McGuire, 1961b | 168 students enrolled in introductory psychology course at the University of Illinois | Two control conditions and 4 (defense type: Active, passive, active-passive, passive-active) × 3 (attack type: no attack, same attacks, new attacks) | Issues were collapsed for analyses. No conclusions drawn about specific health topics | |
| Legalization of marijuana | Compton and Ivanov, 2012 | 142 students (68 female, 74 male, Mage = 19.26 years, age range 18-27), enrolled in communication courses at a Midwestern university, USA | Three condition (control, postmessage threat assessment, interruptive threat assessment), three phase between-subjects experimental design | Participants in a non-traditional inoculation threat assessment condition (i.e., where threat was assessed after explicit forewarning but before refutational pre-emption) were more resistant to counterattitudinal attacks about marijuana legalization than participants in a control condition |
| Ivanov et al., 2012 | 420 students from 5 universities in the USA | 4 (issue: legalization of marijuana, restriction on violent television shows, banning of handguns, legalization of gambling) × 2 (experimental condition: inoculation and control) × 2 (initial attitude valance: positive, negative) | Issues were collapsed for analyses. No conclusions drawn about health topic | |
| Ivanov et al., 2013; study 1 | 101 students (71 female, 30 male), Mage = 20.93 years, age range: 19–31, enrolled in communication courses at a Southeastern university, USA | Participants received one of three inoculation messages in which certainty of attack was manipulated. Univariate ANOVA and subsequent planned comparisons assessed certainty of attack (almost certain not to occur/chance of occurrence about 50–50/almost certain to occur) as predictor variable and threat as outcome variable | Significant differences were observed between the two high certainty groups. Participants told they were very likely to face an attack to their attitudes reported greater levels of threat to those informed that an attack was unlikely | |
| Miller et al., 2013 | 420 students from five universities throughout the USA | 4 (issues: legalization of marijuana, restriction on violent television shows, banning of handguns, legalization of gambling) × 3 (experimental condition: traditional inoculation, reactance enhanced, control) × 2 (counterattitudinal attack language: low controlling, high controlling) | Issues were collapsed for analyses. No conclusions drawn about health topic | |
| Pfau et al., 2004 | 443 students from introductory communication courses at University of Oklahoma, USA | Experimental design (inoculation v control), with analyses involving hierarchical multiple regression and structural equation modeling | Issues were collapsed for analyses. No conclusions drawn about health topic | |
| Pfau et al., 2009 | 281 students from introductory communication courses at a midwestern university, USA | MANCOVA, with experimental condition (control, cognitive inoculation, affective-positive inoculation, and affective-negative inoculation) as independent variable. Initial attitude toward issue position was covariate | Issues were collapsed for analyses. No conclusions drawn about health topic | |
| Pfau et al., 1997b | 790 university students from three departments at a Midwestern university, USA | 3 (experimental condition: cognitive inoculation, peripheral treatment, control) × 2 (need for cognition: lower, higher) between-subjects design | Both central and peripheral inoculation messages resulted in greater resistance to persuasive attacks against marijuana-related attitudes (relative to controls) | |
| Mental illness (contagion of) | McGuire and Papageorgis, 1961 | 130 students in rhetoric courses at University of Illinois, USA | Mixed design involving 4 conditions (base belief, control, writing defense, reading defense) | Issues were collapsed for analyses. No conclusions drawn about specific health topics |
| Unprotected sex (and binge drinking) | Parker et al., 2012 | 120 university students aged 18-21 enrolled in business courses, USA | 2 (experimental condition: inoculation, control) × 2 (experimental issue: unprotected sex, binge drinking) mixed experimental design | Relative to controls, inoculated participants were more able to protect their attitudes from attacks to both treated (unprotected sex) and related but untreated (binge drinking) issues |
| Penicillin effectiveness | McGuire, 1961a | 168 students enrolled in introductory psychology course at the University of Illinois | Eight restoration conditions varying in refutational and supportive elements, and six control conditions | Issues were collapsed for analyses. No conclusions drawn about specific health topics |
| McGuire, 1961b | 168 students enrolled in introductory psychology course at the University of Illinois | Two control conditions and 4 (defense type: Active, passive, active-passive, passive-active) × 3 (attack type: no attack, same attacks, new attacks) | Issues were collapsed for analyses. No conclusions drawn about specific health topics | |
| McGuire and Papageorgis, 1961 | 130 students in rhetoric courses at University of Illinois, USA | Mixed design involving 4 conditions (base belief, control, writing defense, reading defense) | Issues were collapsed for analyses. No conclusions drawn about specific health topics | |
| Smoking initiation | (a) Pfau et al., 1992 | 260 sixth-eighth grade students in two Northeastern USA schools | Both studies employed a 2 (experimental condition: inoculation, control) × 3 (student self-esteem: low, moderate, high) × 2 (gender: male, female) factorial design. Pfau et al. (1992) involved year 1 assessments, Pfau et al. (1992) assessed year 2 outcomes | (a) Inoculation promoted resistance to smoking initiation in year 1, but only among adolescents of low self-esteem |
| (b) Pfau and Van Bockern, 1994 | 1047 seventh grade students in a midwestern city, USA | (b) Modest persistence for inoculative pretreatments over second year. Main effects were observed for inoculation on attitudes in the September 1991 and May 1992 assessments, in addition to an interaction effect between self-esteem and experimental condition in September 1991 that dissipated by May 1992 | ||
| Teeth brushing | McGuire, 1961a | 168 students enrolled in introductory psychology course at the University of Illinois | Eight restoration conditions varying in refutational and supportive elements, and six control conditions | Issues were collapsed for analyses. No conclusions drawn about specific health topics |
| McGuire, 1961b | 168 students enrolled in introductory psychology course at the University of Illinois | Two control conditions and 4 (defense type: Active, passive, active-passive, passive-active) × 3 (attack type: no attack, same attacks, new attacks) | Issues were collapsed for analyses. No conclusions drawn about specific health topics | |
| McGuire and Papageorgis, 1961 | 130 students in rhetoric courses at University of Illinois, USA | Mixed design involving 4 conditions (base belief, control, writing defense, reading defense) | Issues were collapsed for analyses. No conclusions drawn about specific health topics | |
| Tuberculosis screening | McGuire, 1961a | 168 students enrolled in introductory psychology course at the University of Illinois, USA | Eight restoration conditions varying in refutational and supportive elements, and six control conditions | Issues were collapsed for analyses. No conclusions drawn about specific health topics |
| McGuire, 1961b | 168 students enrolled in introductory psychology courses at the University of Illinois, USA | Two control conditions and 4 (defense type: Active, passive, active-passive, passive-active) × 3 (attack type: no attack, same attacks, new attacks) | Issues were collapsed for analyses. No conclusions drawn about specific health topics | |
| Vaccination (childhood) safety (and getting an HPV vaccine) | McGuire and Papageorgis, 1961 | 130 students in rhetoric courses at University of Illinois, USA | Mixed design involving 4 conditions (base belief, control, writing defense, reading defense) | Issues were collapsed for analyses. No conclusions drawn about specific health topics |
| Wong and Harrison, 2014 | 212 female students at a large Southwestern university, USA | MANCOVAs, with experimental condition as independent variable | Inoculation messages about HPV vaccination promoted resistance to messages attacking the perceived safety and efficacy toward the HPV vaccine; Inoculation messages about vaccination in general promoted resistance to messages attacking the perceived safety of HPV vaccines, but not efficacy. Inoculation also promoted childhood vaccinations, measured by attitudes and behavioral intentions |