Effects of normative feedback for drinkers who consume less than the norm: Dodging the boomerang

A pilot study of the acceptability, efficacy, and iatrogenic effects of a brief dynamic norms intervention for reducing young adult alcohol use

BACKGROUND

Alcohol use and its related consequences are a public health problem among young adults. Building upon efficacious personalized normative feedback interventions, dynamic norms can be used to highlight the decreasing prevalence of alcohol use over time among young adults' peers, thereby increasing their motivation to change drinking consistent with the trend. Because limited research has examined dynamic norms feedback interventions for alcohol use, we examined the acceptability and initial efficacy of such an intervention, and potential iatrogenic effects of showing norms feedback about drinking to light drinkers and nondrinkers.

METHODS

Participants were 546 unvaccinated young adults ages 18-24 who completed a baseline survey, intervention, and 1-month follow-up assessment. Participants were block randomized to receive a brief web-based dynamic norms intervention, with feedback content focused on either (a) alcohol-related behaviors (intervention) or (b) COVID-19 vaccine behaviors (the attention-matched control for the present study).

RESULTS

On average, participants who received the alcohol intervention rated it as generally engaging, helpful, and acceptable, with the majority (90.8%) indicating that they would recommend it to a friend. Supporting initial efficacy, in generalized linear models controlling for demographics and baseline alcohol outcomes, at 1-month follow-up the alcohol intervention was associated with statistically and clinically significant reductions in all indices of perceived drinking norms, drinking quantity, drinking frequency, and driving after drinking occasions. Lighter drinkers showed no adverse iatrogenic effects.

CONCLUSIONS

Presenting alcohol-related personalized normative feedback using dynamic trends is a promising intervention for reducing alcohol use in a community sample of young adults. Further research clarifying the optimal presentation of dynamic norms is needed.

The role of perceived social norms in non-suicidal self-injury and suicidality: A systematic scoping review

Social norms are an important influence on health-related behaviours and intention formation. As both suicidal behaviour and non-suicidal self-injury (NSSI) can be motivated by intentions, perceived social norms may have an important role in suicide and NSSI outcomes, although no existing reviews of this association exist. Following the PRISMA Scoping Review extension guidance, a scoping review based on systematic searches of key databases was conducted to identify published English language studies investigating the role of perceived social norms in suicidality and NSSI. Information regarding the types of social norms studied, their relationship to suicidality/NSSI outcomes, study samples and designs was charted. Thirty-six eligible studies (31 quantitative, 4 qualitative, 1 mixed methods) sampling various populations across mostly non-clinical settings were identified and narratively synthesised. Studies varied in how social norms were operationalised, measured, and investigated/explored. Most studies focused on the role of conformity to perceived masculine social norms or to some form of subjective, descriptive, or injunctive norms; there were limited studies on female/feminine norms, pro-social/protective norms, or broader gender/sexuality norms. Most studies (n = 31) were cross-sectional (quantitative) in design, few were based on existing theories of suicide/NSSI or social norms, and none concurrently tested theories of social norms and NSSI/suicidality. Perceived social norms and stronger conformity to norms were generally associated with worse NSSI/suicidality, although some pro-social norms appeared to be protective (e.g., perceived parental norms for adolescents). Whilst conformity to restrictive perceived social norms may be related to poorer suicide and NSSI outcomes, there is a lack of consistency in the literature in how social norms are defined and measured, a lack of theory-based hypothesis testing, and few longitudinal studies. There is a need for more nuanced, theory-based, investigations of how, when, where, why, and for whom, perceived norms have a causal role in NSSI and suicidality outcomes.

Using Alcohol and Cannabis as Sleep Aids: Associations with Descriptive Norms Among College Students

PURPOSE

Young adults may use alcohol and cannabis as sleep aids, a risky behavior that can worsen sleep health over time and lead to substance dependence. Perceived norms for such risky behaviors are often overestimated and related to one's own use. This cross-sectional study examined: (a) the extent to which college students overestimated the prevalence of alcohol and cannabis use as sleep aids (i.e., perceived descriptive norms), and (b) the extent to which perceived descriptive norms were associated with students' own use of alcohol and cannabis as sleep aids.

METHODS

2,642 undergraduate college students (Mage = 18.84 years) reported past 30-day use of alcohol and cannabis as sleep aids. Participants also estimated the percent of college students who use alcohol and cannabis as sleep aids (i.e., perceived descriptive norms).

RESULTS

One-sample t-tests revealed participants, on average, overestimated the norms for using alcohol and cannabis as sleep aids. Participants who endorsed past 30-day use of these substances as sleep aids overestimated these norms to an even greater extent. Count regression models showed perceived descriptive norms were associated with students' use of alcohol and of cannabis as sleeps aids, in respective models, even when controlling for sleep difficulties.

CONCLUSIONS

College students may overestimate the prevalence of using alcohol and cannabis as sleep aids, and students who believe these behaviors are more normative report more frequent use of these substances as sleep aids. Taken together, findings may highlight the potential for norm-correcting strategies as a prudent approach to reducing/preventing the use of alcohol and cannabis as sleep aids.

Testing the Effect of Social Norms Theory-based Interventions: Are they Harmful for University Students who Drink Less than the Peer Norm?

Background. Social norms theory-based interventions have been widely used to reduce alcohol consumption among college and university students. Lately, it has been argued that such interventions may actually increase alcohol use among light drinkers. However, little studies have been focused on testing this possible negative effect. Objectives. The aim of this study was to examine possible negative impact of descriptive normative feedback (DNF) on drinking intentions among students whose baseline drinking scores were below the average of a reference group. We also studied the preventive effect of injunctive normative feedback (INF). Methods. Actual descriptive and injunctive norms were collected from 234 university students. From those who reported drinking below the norm, 26 were randomly assigned to a control or intervention condition that received normative feedback via PowerPoint presentations over two meetings. Results. DNF increased students’ intentions of spirits drinking frequency and quantity. Meanwhile intentions to drink beer, cider, wine and cocktails remained the same. Increased intentions to drink spirits were not reduced by INF. Conclusions. Findings suggest that DNF-based interventions might negatively affect the use of spirits among those students who consume less than their peer norm by increasing their intentions to drink spirits more often and in larger quantities. Ways other than the INF to prevent this negative effect need to be further explored.

Do descriptive norms messaging interventions backfire? Protocol for a systematic review of the boomerang effect

BACKGROUND

Descriptive norms messaging interventions are used to motivate people to adopt or maintain desirable behaviors. Such interventions provide people with information that describes an undesirable behavior as uncommon or a desirable behavior as prevalent within a relevant social group. Descriptive norms messaging interventions have shown promise in increasing individual and social benefit for a broad range of health and sustainability programs. However, evidence suggests that people who have adopted desirable behaviors sometimes regress to undesirable behaviors after receiving descriptive norms messages due to the type of information provided in the messages. This phenomenon is called the boomerang effect. We aim to conduct a systematic review of boomerang effects on health and environmental sustainability behaviors resulting from exposure to descriptive norms messaging interventions.

METHODS

We will employ our search strategy to identify studies of descriptive norms messaging interventions published prior to December 31, 2020. We will search the Cochrane Library, Campbell Library, PsycINFO, PubMed, Social Science Research Network (SSRN), and Web of Science to retrieve peer-reviewed articles published in English. We will restrict inclusion to studies (e.g., randomized and non-randomized controlled trials, quasi-experimental studies, and observational studies) of health and environmental sustainability interventions that assess behaviors before and after exposure to descriptive norms messaging. Two reviewers will independently extract data about study populations and design, intervention components, and behavioral measures. We will use the revised Cochrane Risk of Bias assessment tool (RoB2) and Risk Of Bias in Non-randomized Studies-of Intervention (ROBINS-I) to assess the risk of bias, and the Liverpool Quality Assessment Tool (LQAT) to assess the quality of evidence. We will conduct thematic analyses to codify interventions, and examine intervention effects across subgroups of individuals based on their behavior prior to intervention exposure (e.g., those practicing desirable behaviors vs. undesirable behaviors). We will also conduct moderator analyses to determine whether boomerang effects are contingent upon other factors including intervention framing and delivery modality.

DISCUSSION

This systematic review will provide information about descriptive norms messaging intervention effects across subgroups of individuals and elucidate factors that potentially moderate boomerang effects. The review will yield evidence-based recommendations for the structure and content of descriptive norms messages that can be employed to avoid unintended boomerang effects within the context of health and sustainability programming.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020156989.

When More Is Not Better: Three Common Mistakes in Health Messaging Interventions

Health messaging interventions frequently make three well-intentioned but mistaken choices in their communications strategies. To increase their persuasiveness, these messages frequently call attention to the greatest possible numbers of people engaging in undesirable behavior, victims of this behavior, and reasons why one should change the behavior. We raise recent research suggesting how and why the intuitively attractive more-is-better heuristic can be unproductive, and suggest ways to overcome these pitfalls.

Online personalized normative feedback intervention to reduce event-specific drinking during Mardi Gras

High-risk drinking events (e.g., Mardi Gras) are associated with heavy and problematic drinking behaviors in college students. Online personalized normative feedback (PNF) interventions have been found to reduce college drinking, yet few studies have investigated the effect of event-specific PNF on drinking. The present study investigated the impact of a Mardi Gras-specific PNF intervention on Mardi Gras drinking and normative beliefs. Undergraduate students who reported intending to drink during Mardi Gras were randomly assigned to receive PNF (n = 74) or nondrinking control feedback (n = 73), both delivered online. Compared to those in the control condition, those in the PNF condition reported lower normative beliefs at follow-up. Follow-up beliefs mediated the relation between condition and peak estimated blood alcohol content (eBAC) during Mardi Gras such that the PNF condition was related to lower follow-up maximum estimated eBAC via lower follow-up normative beliefs. Baseline drinking moderated treatment effects such that the PNF was related to lower follow-up eBAC among heavier but not lighter baseline drinkers. This is the first known study to find that an event-specific stand-alone PNF intervention administered online in anticipation of a university-wide holiday associated with drinking can result in decreased event-specific drinking via changes in event-specific normative beliefs. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

A Critical Appraisal of the Social Norms Approach as an Interventional Strategy for Health-Related Behavior and Attitude Change

The Social Norms Approach is a widely used intervention strategy for promoting positive health-related behaviors. The Approach operates on the premise that individuals misperceive their peers' behaviors and attitudes, with evidence of under- and over-estimations of behaviors and peer approval for a range of positive and negative behaviors respectively. The greater these misperceptions, the more likely an individual is to engage in negative behaviors such as consuming heavier amounts of alcohol and other substances and reduce positive behaviors such as eating healthily and using sun protection. However, there are many complexities associated with the use of social norms feedback in interventions and empirical studies. Many social norms interventions do not attempt to change misperceptions of social norms or measure changes in normative perceptions pre- and post-intervention. This has led to a conflation of generic social norms interventions with those that are explicitly testing the Approach's assumptions that it is misperceptions of peer norms which drive behavior. The aim of the present review was to provide a critical appraisal of the use of the Social Norms Approach as an intervention strategy for health-related behaviors, identify the current issues with its evidence base, highlight key opportunities and challenges facing the approach, and make recommendations for good practice when using the approach. There are three core challenges and areas for improved practice when using the Social Norms Approach. Firstly, improvements in the methodological rigor and clarity of reporting of 'social norms' research, ensuring that studies are testing the approach's assumption of the role of misperceptions on behaviors are differentiated from studies investigating other forms of 'social norms.' Secondly, the need for a more explicit, unified and testable theoretical model outlining the development of normative misperceptions which can be translated into interventional studies. Finally, a need for a more robust evaluation of social norms interventions in addition to randomized controlled trials, such as the inclusion of process evaluations, qualitative studies of participant experiences of social norms feedback, and alternative study designs better suited for real-world public health settings. Such improvements are required to ensure that the Social Norms Approach is adequately tested and evaluated.

Cross-cultural examination of college drinking culture in Spain, Argentina, and USA: Measurement invariance testing of the College Life Alcohol Salience Scale

OBJECTIVE

Perceptions about what is "normal" drinking in college, measured by the College Life Alcohol Salience Scale (CLASS; 15 items), have been robustly associated with elevated levels of problematic alcohol use, yet the role of these beliefs has not been studied outside the U.S. The present work examined measurement invariance of the CLASS across sex, drinker status, and in individuals from three different countries (i.e., U.S., Argentina, Spain). Additional goals were to evaluate differences on the CLASS (i.e., latent mean differences) as a function of sex, drinker status and country and to compare construct validity (i.e., correlations with alcohol variables) across sex and different countries.

METHOD

A large sample of 1841 college students enrolled in universities from the U.S., Spain and Argentina completed, via an online survey, a battery of instruments that assess college alcohol beliefs, drinking motives, alcohol consumption and alcohol-related negative consequences.

RESULTS

We found that a shortened 12-item version of the CLASS to be invariant across sex and drinker status, but only metric invariance was found across countries. As expected, men and drinkers showed significantly higher scores on the CLASS than women and non-drinkers, respectively. Bivariate correlations between CLASS scores and drinking outcomes strongly supported criterion-related validity of this measure across multiple countries and sex with differing strengths in relationships with alcohol-related constructs.

CONCLUSIONS

Taken together, perceptions of the centrality of alcohol to the college experience appear to be an important target for college student alcohol interventions across various cultures and countries, especially for male college student drinkers.

Evaluation of Alcohol-Related Personalized Normative Feedback With and Without an Injunctive Message

OBJECTIVE

Personalized normative feedback (PNF) has been used extensively to reduce alcohol consumption, particularly among heavy drinkers. However, the majority of PNF studies have used only descriptive norms (real or perceived pervasiveness of a given behavior). The purpose of the current study was to explore the efficacy of PNF both with and without an injunctive message indicating approval or disapproval based on the participants' standing relative to other students' drinking levels. This randomized trial evaluated two brief web-based alcohol intervention conditions (descriptive-norms-feedback-only condition versus a descriptive-plus-injunctive-message condition relative to an assessment-only control condition).

METHOD

Participants included 176 students who had reported at least one heavy drinking episode in the past month. Participants completed baseline and follow-up assessments of perceived norms and drinking. Follow-up assessments were completed at 2 weeks post-intervention by 165 (94%) participants.

RESULTS

Analyses were conducted using zero-inflated negative binomial regression models. As expected, the descriptive-norms-only condition was effective in reducing drinking among heavier baseline drinkers at follow-up relative to the control condition. However, contrary to expectations, the descriptive-plus-injunctive-message condition did not predict less drinking at follow-up.

CONCLUSIONS

This study was unique in using an injunctive message as an adjunct to descriptive-norms feedback within the context of drinking. Findings highlight the need for additional research into the role of defensiveness, which may serve as an impediment to using injunctive norms/messages in interventions for problematic substance use and other potentially stigmatizing behaviors.

Are young men who overestimate drinking by others more likely to respond to an electronic normative feedback brief intervention for unhealthy alcohol use?

AIM

To tested whether the efficacy of an internet-based brief intervention that included normative drinking feedback varied with estimations of the drinking of others.

METHODS

This study is a secondary analysis of a randomized controlled trial showing an intervention effect on weekly drinking. Participants were males with unhealthy alcohol use (mean age [SD]=20.8 [1.1]). Before the trial, participants were asked to estimate the percentage of men their age who drink more than they do. Using their self-reported drinking data, the "perceived" percentage of people their age and gender who drink more than they do, and data from Swiss statistics, we classified participants as overestimating (>+10%), accurately (-10% to +10%) or underestimating (<-10%) drinking by others.

RESULTS

Of 734 participants with complete data, 427 overestimated, 205 accurately estimated and 102 underestimated the drinking of others. The mean (SD) number of drinks per week was 9.8 (7.9) and AUDIT score was 10.6 (4.2). In stratified negative binomial regression models predicting drinks per week, at 6months, and controlling for baseline drinks per week, the intervention was effective among those overestimating (IRR[95%CI]=0.86[0.74;0.98]), but showed no effect among those accurately estimating (IRR[95%CI]=0.83[0.66;1.03]) or underestimating IRR[95%CI]=1.21[0.92;1.60]) the drinking of others.

CONCLUSIONS

Perception of drinking by others appears to be a moderator of effect of an electronic feedback intervention among hazardous drinkers. This finding is consistent with the hypothesis that correcting the perceptions of others' drinking is a potential mechanism of action in normative feedback paradigms.

An exploratory pilot study of mechanisms of action within normative feedback for adult drinkers

Background. Normative feedback (NF), or receiving information about one’s drinking compared to peer drinking norms, is one of the most widely used brief interventions for prevention and intervention for hazardous alcohol use. NF has demonstrated predominantly small but significant effect sizes for intention to change and other drinking related outcomes. Identifying mechanisms of action may improve the effectiveness of NF; however, few studies have examined NF’s mechanisms of action, particularly among adults.

Objective. This study is an exploratory analysis of two theorized mechanisms of NF: discrepancy (specifically personal dissonance—the affective response to feedback) and belief in the accuracy of feedback.

Method. Using Amazon’s Mechanical Turk, 87 men (n = 56) and women (n = 31) completed an online survey during which they were asked about their perceptions about their drinking and actual drinking behaviors. Then participants were provided tailored NF and evaluated for their reactions. Severity of discrepancy was measured by the difference between one’s estimated percentile ranking of drinking compared to peers and actual percentile ranking. Surprise and worry reported due to the discrepancy were proxies for personal dissonance. Participants were also asked if they believed the feedback and if they had any plans to change their drinking. Mediation analyses were implemented, exploring whether surprise, worry, or belief in the accuracy of feedback mediated severity of discrepancy’s impact on plan for change.

Results. Among this sample of adult drinkers, severity of discrepancy did not predict plan for change, and personal dissonance did not mediate severity of discrepancy. Severity of discrepancy was mediated by belief in the accuracy of feedback. In addition, viewing one’s drinking as a problem prior to feedback and post-NF worry both predicted plan for change independently.

Conclusions. Results revealed that NF may not work to create personal dissonance through discrepancy, but belief in the accuracy of feedback may be important. It appears the more one believes the feedback, the more one makes a plan for change, suggesting practitioners should be mindful of how information within feedback is presented. Findings also indicate NF may work by validating a preexisting perception that drinking is a problem instead of creating concern related to discrepancy where none existed. Limitations regarding generalizability are discussed.

Do As I Say, Not As I Do

Little is known about the drinking behaviors and perceptions of the peers facilitating campus alcohol interventions. The current study examined these trajectories in peer counselors ( N = 12) providing personalized normative feedback interventions to undergraduates mandated to clinical services. Peer counselors completed four monthly self-assessments. In spite of facilitating interventions to reduce drinking and associated harms, peer drinking behaviors and expectancies did not change, although significant between subjects effects suggest various trajectories. Peer counselors did correct overestimates of binge drinking but progressively underestimated abstinence norms. Despite the lack of change in the peer counselor behaviors, the mandated clients significantly reduced their drinking, suggesting it may be more important to "Do as I Say" rather than as the facilitator does.

Internet-Based Brief Intervention to Prevent Unhealthy Alcohol Use among Young Men: A Randomized Controlled Trial

Introduction

Alcohol use is one of the leading modifiable morbidity and mortality risk factors among young adults.

Study Design

2 parallel-group randomized controlled trial with follow-up at 1 and 6 months.

Setting/Participants

Internet based study in a general population sample of young men with low-risk drinking, recruited between June 2012 and February 2013.

Intervention: Internet-based brief alcohol primary prevention intervention (IBI). The IBI aims at preventing an increase in alcohol use: it consists of normative feedback, feedback on consequences, calorific value alcohol, computed blood alcohol concentration, indication that the reported alcohol use is associated with no or limited risks for health. Intervention group participants received the IBI. Control group (CG) participants completed only an assessment.

Main Outcome Measures

Alcohol use (number of drinks per week), binge drinking prevalence. Analyses were conducted in 2014–2015.

Results

Of 4365 men invited to participate, 1633 did so; 896 reported low-risk drinking and were randomized (IBI: n = 451; CG: n = 445). At baseline, 1 and 6 months, the mean (SD) number of drinks/week was 2.4(2.2), 2.3(2.6), 2.5(3.0) for IBI, and 2.4(2.3), 2.8(3.7), 2.7(3.9) for CG. Binge drinking, absent at baseline, was reported by 14.4% (IBI) and 19.0% (CG) at 1 month and by 13.3% (IBI) and 13.0% (CG) at 6 months. At 1 month, beneficial intervention effects were observed on the number of drinks/week (p = 0.05). No significant differences were observed at 6 months.

Conclusion

We found protective short term effects of a primary prevention IBI.

Trial Registration

Controlled-Trials.com ISRCTN55991918

Stand-Alone Personalized Normative Feedback for College Student Drinkers: A Meta-Analytic Review, 2004 to 2014

Background

Norms clarification has been identified as an effective component of college student drinking interventions, prompting research on norms clarification as a single-component intervention known as Personalized Normative Feedback (PNF). Previous reviews have examined PNF in combination with other components but not as a stand-alone intervention.

Objectives

To investigate the degree to which computer-delivered stand-alone personalized normative feedback interventions reduce alcohol consumption and alcohol-related harms among college students and to compare gender-neutral and gender-specific PNF.

Data Sources

Electronic databases were searched systematically through November 2014. Reference lists were reviewed manually and forward and backward searches were conducted.

Selection Criteria

Outcome studies that compared computer-delivered, stand-alone PNF intervention with an assessment only, attention-matched, or active treatment control and reported alcohol use and harms among college students.

Methods

Between-group effect sizes were calculated as the standardized mean difference in change scores between treatment and control groups divided by pooled standard deviation. Within-group effect sizes were calculated as the raw mean difference between baseline and follow-up divided by pooled within-groups standard deviation.

Results

Eight studies (13 interventions) with a total of 2,050 participants were included. Compared to control participants, students who received gender-neutral (d_between = 0.291, 95% CI [0.159, 0.423]) and gender-specific PNF (d_between = 0.284, 95% CI [0.117, 0.451]) reported greater reductions in drinking from baseline to follow-up. Students who received gender-neutral PNF reported 3.027 (95% CI [2.171, 3.882]) fewer drinks per week at first follow-up and gender-specific PNF reported 3.089 (95% CI [0.992, 5.186]) fewer drinks. Intervention effects were small for harms (d_between = 0.157, 95% CI [0.037, 0.278]).

Conclusions

Computer-delivered PNF is an effective stand-alone approach for reducing college student drinking and has a small impact on alcohol-related harms. Effects are small but clinically relevant when considered from a public health perspective. Additional research is needed to examine computer-delivered, stand-alone PNF as a population-level prevention program.

Interventions to reduce college student drinking: State of the evidence for mechanisms of behavior change

Interventions to reduce college student drinking, although efficacious, generally yield only small effects on behavior change. Examining mechanisms of change may help to improve the magnitude of intervention effects by identifying effective and ineffective active ingredients. Informed by guidelines for establishing mechanisms of change, we conducted a systematic review of alcohol interventions for college students to identify (a) which constructs have been examined and received support as mediators, (b) circumstances that enhance the likelihood of detecting mediation, and (c) the extent of evidence for mechanisms of change. We identified 61 trials that examined 22 potential mediators of intervention efficacy. Descriptive norms consistently mediated normative feedback interventions. Motivation to change consistently failed to mediate motivational interviewing interventions. Multiple active ingredient interventions were not substantially more likely to find evidence of mediation than single ingredient interventions. Delivering intervention content remotely reduced likelihood of finding support for mediation. With the exception of descriptive norms, there is inadequate evidence for the psychosocial constructs purported as mechanisms of change in the college drinking literature. Evidence for mechanisms will be yielded by future studies that map all active ingredients to targeted psychosocial outcomes and that assess potential mediators early, inclusively, and at appropriate intervals following interventions.

Descriptive norms and expectancies as mediators of a brief motivational intervention for mandated college students receiving stepped care for alcohol use

Stepped care approaches for mandated college students provide individual brief motivational interventions (BMI) only for individuals who do not respond to an initial, low-intensity level of treatment such as Brief Advice (BA). However, how BMIs facilitate change in this higher-risk group of mandated students remains unclear. Perceived descriptive norms and alcohol-related expectancies are the most commonly examined mediators of BMI efficacy but have yet to be examined in the context of stepped care. Participants were mandated college students (N = 598) participating in a stepped care trial in which mandated students first received BA. Those who reported continued risky drinking 6 weeks following a BA session were randomized to either a single-session BMI (N = 163) or an assessment-only comparison condition (AO; N = 165). BMI participants reduced alcohol-related problems at the 9 month follow up significantly more than AO participants. Multiple mediation analyses using bootstrapping techniques examined whether perceived descriptive norms and alcohol-related expectancies mediated the observed outcomes. Reductions in perceptions of average student drinking (B = -.24; 95% CI [-.61, -.04]) and negative expectancies (B = -.13; 95% CI [-.38, -.01]) mediated the BMI effects. Furthermore, perceived average student norms were reduced after the BMI to levels approximating those of students who had exhibited lower risk drinking following the BA session. Findings highlight the utility of addressing perceived norms and expectancies in BMIs, especially for students who have not responded to less intensive prevention efforts.