Electronic cigarette social norms among adolescents in New South Wales, Australia.

The use of electronic cigarettes (e-cigarettes) is common and increasing, especially among youth. In 2022/2023, 30% of 12- to 17-year-olds reported ever using e-cigarettes in Australia-a >50% increase from 2017 (14%). Several adverse e-cigarette health effects have been identified and most effects remain unknown. Social norms, rules that govern social behaviours, are associated with current and future adolescent e-cigarette use. Understanding social norms in Australian adolescents is critical to the development of targeted and effective e-cigarette prevention activities. This study aims to explore e-cigarette social norms among adolescents living in New South Wales, Australia. A total of 32 online single or paired semi-structured qualitative interviews were conducted involving 46 participants aged 14-17 years, as part of the Generation Vape project. Reflexive thematic analysis was applied within a constructivist perceptive. Adolescents perceived e-cigarettes use as prolific among their peers, with use considered common, acceptable and normal. Fuelled by social exposure to e-cigarettes, 'everyone' was generally thought to be using them (descriptive norms). E-cigarette use was considered so entrenched that it was part of adolescent identity, with abstinence regarded as atypical. Use was driven by an internalised desire to fit it (injunctive norm), rather than being attributed to overt/external 'peer-pressure'. Positive e-cigarette norms exist among Australian adolescents with norm formation strongly influenced by social exposure, including e-cigarette promotion. Prevention efforts should include limiting adolescent exposure to e-cigarette marketing to help redefine existing pro-e-cigarette social norms and protect health.

Interpreting human rights as the social psychological phenomenon of rights claiming.

In the last 5 years, the intersection between psychology and human rights has become more evident, with influential international, national and local human rights institutions, including the American Psychological Association, issuing reports and resolutions on the topic. Within jurisprudence, human rights are less of a legalistic regulatory enactment and more of what social psychologists refer to as injunctive norms. We argue that conceptualising human rights as the social-psychological process of both creating and aligning injunctive and descriptive norms clarifies human rights and makes them more accessible to groups and individuals in society engaged in rights claiming. Rights claiming is a term we use to describe the moral cognitive process of people engaged in individual and/or collective behaviour aimed at securing their social identity within the public sphere where that identity is marginalised or the subject of discrimination. We argue that placing rights claiming at the centre of human rights psychology advances human rights. Focusing psychological research on social identity, the alignment of injunctive norms, deontic moral cognitions, human dignity, social dominance orientations and collective and individual behaviours forms part of securing a clear specialty in psychological science dedicated to human rights and advancing the American Psychological Association (APA)'s human rights mandate.

Social Influence and Group Identity.

This chapter reviews research on the group identity explanation of social influence, grounded in self-categorization theory, and contrasts it with other group-based explanations, including normative influence, interdependence, and social network approaches, as well as approaches to persuasion and influence that background group (identity) processes. Although the review primarily discusses recent research, its focus also invites reappraisal of some classic research in order to address basic questions about the scope and power of the group identity explanation. The self-categorization explanation of influence grounded in group norms, moderated by group identification, is compared and contrasted to other normative explanations of influence, notably the concept of injunctive norms and the relation to moral conviction. A range of moderating factors relating to individual variation, features of the intragroup and intergroup context, and important contextual variables (i.e., anonymity versus visibility, isolation versus copresence) that are particularly relevant to online influence in the new media are also reviewed.

Examining alcohol-related social norms among international and domestic students in the United States.

OBJECTIVES: The purpose of the current study is to examine college student status (international vs. domestic) across alcohol social norms perception. METHODS: Undergraduates (n = 3081) were recruited for the study. Most participants were female (69.9%) and White (98.2%), with the average age of participants was 19.97 (SD = 1.61). Approximately 17.3% (n = 534) of the students were international (i.e., nonresident alien who are in the US for a bachelor's degree). It is a cross-sectional study. RESULTS: International students reported significantly lower social norms than domestic students. International students in later college years reported norms closer to domestic students. International women endorsed social norms at a higher level than international men. CONCLUSIONS: Assimilation into U.S. drinking culture may be linked with increased support of drinking norms among International students. This study shows the importance of incorporating drinking norms prevention strategy and cultural diversity awareness training to increase international students' knowledge and prevent misconceptions. International students' social norms should be examined for future drinking interventions. Interventions for college drinking should target specific events and context with short-term increase in hazardous drinking behavior but long-lasting effects.

The effect of classroom aggression-related peer group norms on students' short-term trajectories of aggression.

Using a four-wave/seven-month longitudinal design with a sample of 1595 preadolescents (53% boys, 47% girls, Mage = 10.2 years) from 63 fourth-, fifth- and sixth- grade classrooms in nine mixed-sex schools in Bogotá, Colombia, we examined whether growth trajectories of measures of overt and relational aggression varied as a function of classroom norms for aggression. Multilevel growth mixture modeling revealed (a) distinct trajectories of overt and relational aggression for boys and girls and (b) that norm salience (i.e., the process by which a group norm is made salient via the punishments or reinforcements to the behavior within the group) was a better predictor of associations with trajectories of overt and relational aggression than were perceived injunctive norms (i.e., the perceived standards of what is approved or disapproved in a social context). In classrooms where popular or accepted children were perceived by their peers as aggressive, more boys followed an increasing trajectory of overt and relational aggression than a low-stable trajectory, and more girls followed a high-stable trajectory of relational aggression than a low-stable trajectory. These findings are discussed in terms of the practical implications for the design of educational interventions aimed at preventing aggression in classroom settings.

Relevance of Athlete-Specific Psychosocial Factors in High School Student-Athlete Alcohol Consumption.

Background: Research suggests that adolescent student-athletes are at heightened risk for alcohol consumption. The identification of unique, modifiable risk factors for alcohol use in this population is needed. Purpose/Objectives: Building on previous work highlighting the importance of each of athlete-specific drinking motives and alcohol expectancies, this study investigated whether athlete-specific psychosocial predictors optimize our ability to predict adolescent athlete alcohol consumption after accounting for general psychosocial predictors. Methods: Participants were 352 current high school student-athletes who completed a self-report questionnaire about their alcohol use attitudes, behaviors, and cognitions. Results: Hierarchical regression revealed that among the total sample, gender, class year, liquid courage/sociability, sexuality, and negative alcohol expectancies, and negative athletic-functioning alcohol expectancies predicted alcohol consumption. Among lifetime drinkers, gender, class year, enhancement motives, conformity motives (negative), negative athlete-functioning alcohol expectancies, and sport-related coping motives predicted alcohol consumption. Conclusions/Importance: Negative athletic-functioning alcohol expectancies and sport-related coping motives emerged as important, athlete-specific predictors of adolescent athlete alcohol use. These factors provide important opportunities for targeted prevention efforts.

It's Not All Smoke and Mirrors: The Role of Social Norms, Alcohol Use, and Pandemic Partying in e-Cigarette Use During COVID-19.

BACKGROUND: E-cigarette use among college students is increasing. In the era of COVID-19, such usage is especially dangerous given that the virus can be deadly for those with impaired respiratory systems. A small but growing body of research suggests that social norms may predict e-cigarette use. However, one's perception of e-cigarette use behaviors (descriptive norms) and approval by peers (injunctive norms) have yet to be studied in college students. The overarching purpose of this study is to determine whether descriptive and injunctive norms for e-cigarette use contribute unique variance to past 30-day e-cigarette use. Methods: Using a sample of 191 students (138 women) surveyed from introductory-level courses at a university in the northeastern United States, we explored the relationships between student demographic characteristics, alcohol use, binge drinking, COVID-19 non-compliant party attendance on and off campus, and social norms with past 30-day e-cigarette use using sequential regression. Two models were utilized to determine if descriptive and injunctive e-cigarette use norms predicted e-cigarette use after controlling for demographic characteristics in the social norms model, and above and beyond demographics and COVID-19 noncompliant party attendance, alcohol use, and binge drinking in the party behaviors model. Results: The results demonstrated that descriptive and injunctive norms for e-cigarette use significantly predicted e-cigarette use in both models, controlling for all covariates. Conclusions/Importance: Findings highlight the importance of social norms in predicting e-cigarette use during the COVID-19 pandemic, identifying areas for prevention and intervention for public health officials and higher education administrators.

Understanding Perceptions of Nonsuicidal Self-Injury: Descriptive and Injunctive Norms.

Nonsuicidal self-injury (NSSI) is a major public health concern. Web-based personalized feedback interventions (PFIs) may be a cost-effective and efficient way to treat NSSI. In order to develop a PFI, it is imperative to assess descriptive and injunctive norms. The current study examines descriptive and injunctive norms of NSSI within college students and adults in the community, comparing how perceived norms may differ for those who do or do not engage in NSSI. Study 1 calculated percentages of NSSI behavior within the student sample. Study 2 then examined perceived descriptive and injunctive norms between those with and without history of NSSI in both samples. Study 1 indicated that 19% of undergraduate students had histories of NSSI. Additionally, there was a general tendency to overestimate the percentage of people who engage in NSSI and the number of times a typical person engages in NSSI. Finally, those who engaged in NSSI believed that most people do not understand why individuals engage in NSSI; comparatively, the majority of people without history of NSSI still indicated that they understand why others would engage in NSSI. These research findings may be utilized in a PFI to reduce shame and NSSI behavior.

Longitudinal Associations Between Perceptions of Peer Group Drinking Norms and Students' Alcohol Use Frequency Within College Sport Teams.

BACKGROUND: Students' alcohol use behaviors are shaped by the attitudes and behaviors of others, especially the peers within students' proximal social groups. Explaining the association between perceived drinking norms and alcohol use, researchers propose contradicting pathways that focus on conformity (i.e., social norms predict alcohol use) and projection (i.e., alcohol use predicts perceived norms). The current study examined the extent to which conformity and projection processes were evident in the association between college student alcohol use and the perceived alcohol use norms for students' club sport teams. METHODS: The sample comprised 1,054 college students (61% female) nested in 35 intact same-sex club sport teams. On 3 separate occasions during a single school year (3-month lag), participants reported drinking frequency and perceptions of descriptive and injunctive group drinking norms. We employed random intercepts cross-lagged panel modeling to estimate prospective within-person associations separately from stable trait-like between-person associations. RESULTS: Descriptive and injunctive group drinking norms were both positively related to students' alcohol use frequency at the between-person level. Individuals nevertheless demonstrated variability at the within-person level. Results revealed a strong contemporaneous association between descriptive norms and alcohol use frequency within each timepoint, but no prospective associations. Models including perceptions of injunctive drinking norms demonstrated similar contemporaneous associations with alcohol use frequency, but also identified significant prospective associations signifying conformity. CONCLUSIONS: Findings align with previous research reporting a strong and positive association between student's self-reported alcohol use and subjective peer alcohol use norms. After disentangling within- and between-person effects to probe for conformity and projection processes, the current findings are somewhat contrary to previous research that has reported reciprocal relationships between social norms and alcohol use behavior. Further investigation of the potential conformity and projection mechanisms of social norms is critical to advance norm-based strategies to reduce harm.

Exploring the directionality in the relationship between descriptive and injunctive parental and peer norms and snacking behavior in a three-year-cross-lagged study.

BACKGROUND: People's eating behavior is assumed to be influenced by what other people do (perceived descriptive norms) and what others approve of (perceived injunctive norms). It has been suggested that adolescents are more susceptible to peer norms than parental norms, because they experience a strong need for group acceptance that leads to conforming to peer group norms. The current study examined changes in snacking behavior and four types of social norms (i.e., parental and peer descriptive and injunctive norms) that promoted fruit and vegetable intake among adolescents. This study was the first to examine whether snacking behavior also influenced norm perceptions by testing the directionality of these associations. METHODS: The study consisted of 819 participants (M [SD] age = 11.19 [1.36]; 46.1% boys), collected at three time points (T1 = 2016, T2 = 2017 and T3 = 2018) during the MyMovez project. Self-reported frequency of snack consumption, perceived parental and peer descriptive and injunctive norms were assessed. The primary analysis consisted of a series of cross-lagged autoregressive models specified in a structural equation modeling framework. RESULTS: Model comparisons testing the descriptive and injunctive norms in separate models and in an additional combined model revealed evidence for bi-directional associations between norms and snacking behavior. Descriptive peer and parent norms were not found to have an effect on subsequent snacking behaviors. Perceived injunctive parental norms were positively associated with healthy snack food intake and negatively associated with unhealthy snack intake (forward direction). Injunctive peer norms were negatively associated with healthy snack food intake. In addition, higher unhealthy snack food intake was negatively associated with the perception of descriptive and injunctive parental norms 1 year later (reversed direction). We did not find peer norms to be more closely associated with changes in snacking behaviors compared to parental norms. CONCLUSIONS: Parents expecting their children to snack healthy had a positive influence on healthy snacking behavior whereas only acting as a healthy role model did not. Future research should address the possible interaction between descriptive and injunctive norms. Research should also take into account the bi-directional relations between eating behaviors and normative perceptions.

Norms and Attitudes about Being an Active Bystander: Support for Telling Adults about Seeing Knives or Guns at School among Greater London Youth.

A detailed understanding of the factors associated with support among youth for reporting a knife or gun at school to an adult is essential to inform violence prevention initiatives. However, no studies have empirically assessed attitudes about support for reporting among secondary school students in Greater London nor perceived norms about such support among peers. Thus, this study explores whether students misperceive peer norms about support for telling adults about seeing weapons at school. Anonymous surveys were completed by 7401 youth (52% female; 43% White; mean age 11.8 years) in school years 4-11 in 45 school cohorts in a greater London borough between 2007 and 2012. Students reported both personal support about reporting weapons to several categories of adults and whether they perceived most other students at their school to support reporting weapons to adults in each category. Most students (64-78% on average) in most cohorts personally thought that students should report seeing a weapon at school to head teachers, police/security guard, teachers/counselors, and parent/other adult relatives. However, 34-44% of students erroneously thought that the majority of their peers did not support reporting to these adults. Perceived norms predicted personal support for reporting, adjusting for the prevalence of actual support at one's school and other factors. Pervasive norm misperceptions about reporting may contribute to a less safe environment.

"They Think that I Should Defend": Effects of Peer and Teacher Injunctive Norms on Defending Victimized Classmates in Early Adolescents.

Norms have been suggested as important characteristics of the social-ecological context for defending victimized peers, but little is known about the contribution of student perceived injunctive norms (regarding the appropriateness of defending) imposed by peers and teachers. To investigate the role of these norms in defending, a sample of 751 early adolescents (51% female; Mage at Time 1:13 years) was assessed at two time points. Defending, as measured by peer- and self-ratings, decreased slightly over a six-month timespan. Three-level models (with time, students, and classrooms as the levels) indicated that both individual- and classroom-level perceived peer injunctive norms (but not teacher injunctive norms) had positive effects on defending over time regardless of the source of the information on defending (peers or self). These findings support programs that encourage defending through peer norms.

A Randomized-Controlled Trial of Social Norm Interventions to Increase Physical Activity.

BACKGROUND: Physical activity confers numerous health benefits, yet few adults meet recommended physical activity guidelines. PURPOSE: The impact of brief messages providing descriptive and injunctive social norm feedback on physical activity was tested in this conceptual pilot study. METHODS: Young adults (N = 111) were randomly assigned to one of three conditions: descriptive norm feedback, descriptive-plus-injunctive norm feedback, or no social feedback (control condition). Participants used pedometers for eight weekdays and recorded their step counts each evening. The descriptive norm group received feedback about the average number of steps taken by group members the previous day. The descriptive-plus-injunctive norm group received feedback about the group average, as well as a sad face if the participant was below the average or a happy face if the participant was above the average. The control group received no feedback throughout the study. RESULTS: By days 7 and 8, the descriptive-plus-injunctive norm group reported significantly more steps relative to the control group, whereas the descriptive norm group showed a trend toward higher step counts relative to the control group. These effects did not differ for participants above versus below the group average at baseline. CONCLUSION: The combined use of descriptive and injunctive social norms increased physical activity over a short period. This simple feedback strategy has potential for achieving wide reach and dissemination on its own or combined with more comprehensive interventions. This initial evidence can guide larger trials of longer duration. TRIAL REGISTRATION NUMBER: The trial was registered with the ClinicalTrials.gov database (NCT02710201).

The Role of Norms in Marijuana Use Among American Indian Adolescents.

American Indian adolescents residing on reservations report high levels of marijuana use. Understanding the relationships between normative mechanisms and marijuana use in this group can be especially important in designing effective strategies to prevent use. Participants were 3446 students identifying as American Indian in grades 7-12 across four academic years (2009-2012) from 45 schools. Multilevel logistic analysis was used to examine the relationships between lifetime, last month, and frequent marijuana use and measures of the normative environment. Descriptive and injunctive norms were distinctly and directly associated with all measures of marijuana use, with family injunctive norms showing a strong relationship to use (0.49 < OR < 0.58 for a 9th grade student). Family injunctive norms moderated the relationship between descriptive norms and lifetime and last month use (OR = 0.79 and 0.82, respectively), with higher family disapproval associated with a weaker relationship between descriptive norms and use. Anticipatory socialization was positively related to all measures of marijuana use, with the relationship stronger for lifetime and last month use than for frequent use (OR = 1.88, 1.74, and 1.30, respectively). A contextual variable of descriptive norms was related to lifetime and last month use (OR = 1.66 and 1.51, respectively) but not frequent use. These findings reinforce the importance of parental norms in reducing the likelihood of using marijuana. In addition, prevention strategies that increase the perception that healthy behaviors not involving marijuana use are an enjoyable way to socialize may be more effective in preventing occasional marijuana use.

Injunctive Norms and Alcohol Consumption: A Revised Conceptualization.

BACKGROUND: Injunctive norms have been found to be important predictors of behaviors in many disciplines with the exception of alcohol research. This exception is likely due to a misconceptualization of injunctive norms for alcohol consumption. To address this, we outline and test a new conceptualization of injunctive norms and personal approval for alcohol consumption. Traditionally, injunctive norms have been assessed using Likert scale ratings of approval perceptions, whereas descriptive norms and individual behaviors are typically measured with behavioral estimates (i.e., number of drinks consumed per week, frequency of drinking). This makes comparisons between these constructs difficult because they are not similar conceptualizations of drinking behaviors. The present research evaluated a new representation of injunctive norms with anchors comparable to descriptive norms measures. METHODS: A study and a replication were conducted including 2,559 and 1,189 undergraduate students from 3 different universities. Participants reported on their alcohol-related consumption behaviors, personal approval of drinking, and descriptive and injunctive norms. Personal approval and injunctive norms were measured using both traditional measures and a new drink-based measure. RESULTS: Results from both studies indicated that drink-based injunctive norms were uniquely and positively associated with drinking, whereas traditionally assessed injunctive norms were negatively associated with drinking. Analyses also revealed significant unique associations between drink-based injunctive norms and personal approval when controlling for descriptive norms. CONCLUSIONS: These findings provide support for a modified conceptualization of personal approval and injunctive norms related to alcohol consumption and, importantly, offer an explanation and practical solution for the small and inconsistent findings related to injunctive norms and drinking in past studies.

Addressing Inconsistencies in the Social Norms Drinking Literature: Development of the Injunctive Norms Drinking and Abstaining Behaviors Questionnaire.

BACKGROUND: Informed by inconsistent findings regarding the association between injunctive norms (IN) and drinking behaviors, the current study developed a new measure of IN, the Injunctive Norms Drinking and Abstaining Behaviors Questionnaire (IN-DABQ). This measure addressed several psychometric weaknesses of prior assessment of this construct, specifically, reliance on single-item measures, and assessment of a limited range of drinking behaviors. The new measure also assessed norms for reasons for abstaining from drinking as college students often have simultaneous motives to use and inhibit their drug use. A parallel measure of descriptive norms (DN), the Descriptive Norms Drinking and Abstaining Behaviors Questionnaire (DN-DABQ), was created to allow for a comparison of the relative predictive effects of descriptive and IN in relation to different drinking outcomes. METHODS: A college sample (N = 254, female = 50.42%) was recruited using Amazon's Mechanical Turk. Participants completed an online survey assessing demographic characteristics, social norms for 3 referents, weekly alcohol use, and alcohol-related consequences. RESULTS: Exploratory factor analyses indicated 2 factors for the DN-DABQ and 3 factors for the IN-DABQ. The IN Drinking Behaviors factor consistently predicted weekly consumption and alcohol-related consequences across 3 reference groups (typical college student at your school, friends, and closest friends). CONCLUSIONS: These findings suggest that prior inconsistencies in the relationship between IN and drinking behaviors are likely a function of poor measurement of this construct. Implications for normative feedback interventions are discussed.

Social Anxiety and Cannabis-Related Impairment: The Synergistic Influences of Peer and Parent Descriptive and Injunctive Normative Perceptions.

OBJECTIVES: Cannabis users, especially socially anxious cannabis users, are influenced by perceptions of other's use. The present study tested whether social anxiety interacted with perceptions about peer and parent beliefs to predict cannabis-related problems. METHODS: Participants were 148 (36.5% female, 60.1% non-Hispanic Caucasian) current cannabis users aged 18-36 (M = 21.01, SD = 3.09) who completed measures of perceived descriptive and injunctive norms, social anxiety, and cannabis use behaviors. Hierarchical multiple regressions were employed to investigate the predictive value of the social anxiety X parent injunctive norms X peer norms interaction terms on cannabis use behaviors. RESULTS: Higher social anxiety was associated with more cannabis problems. A three-way interaction emerged between social anxiety, parent injunctive norms, and peer descriptive norms, with respect to cannabis problems. Social anxiety was positively related to more cannabis problems when parent injunctive norms were high (i.e., perceived approval) and peer descriptive norms were low. Results further showed that social anxiety was positively related to more cannabis problems regardless of parent injunctive norms. CONCLUSIONS: The present work suggests that it may be important to account for parent influences when addressing normative perceptions among young adult cannabis users. Additional research is needed to determine whether interventions incorporating feedback regarding parent norms impacts cannabis use frequency and problems.

The Effect of Descriptive Norms on Pregaming Frequency: Tests of Five Moderators.

BACKGROUND: Pregaming is highly prevalent on college campuses and associated with heightened levels of intoxication and risk of alcohol consequences. However, research examining the correlates of pregaming behavior is limited. Descriptive norms (i.e., perceptions about the prevalence or frequency of a behavior) are reliable and comparatively strong predictors of general drinking behavior, with recent evidence indicating that they are also associated with pregaming. OBJECTIVES: We tested the hypothesis that higher descriptive norms for pregaming frequency would be associated with personal pregaming frequency. We also tested whether this effect would be stronger in the context of several theory-based moderators: female gender, higher injunctive norms (i.e., perceptions of others' attitudes toward a particular behavior), a more positive attitude toward pregaming, a stronger sense of identification with the drinking habits of other students, and stronger social comparison tendencies. METHODS: College student drinkers (N = 198, 63% female) participated in an online survey assessing frequency of pregaming, descriptive norms, and hypothesized moderators. RESULTS: A multiple regression model revealed that higher descriptive norms, a more positive attitude toward pregaming, and stronger peer identification were significantly associated with greater pregaming frequency among drinkers. However, no moderators of the association between descriptive norms and pregaming frequency were observed. CONCLUSIONS/IMPORTANCE: Descriptive norms are robust predictors of pregaming behavior, for both genders and across levels of several potential moderators. Future research seeking to understand pregaming behavior should consider descriptive norms, as well as personal attitudes and identification with student peers, as targets of interventions designed to reduce pregaming.

Dangerous Beliefs: College Alcohol Beliefs Are Associated With Increased Risk of Regretted Sexual Encounters.

This study explored the relative impact of college alcohol beliefs (CABs; i.e., the extent to which the student views alcohol as part of the fabric of college life), descriptive norms, injunctive norms, positive alcohol expectancies, and sensation seeking on college students' (N = 415) risk for engaging in regretted sexual encounters (RSE). Overall, 12% of our sample reported having experienced RSE within the past 30 days. When pitted against the other traditional predictors of college student drinking and its consequences, such as positive alcohol expectancies, descriptive and injunctive norms, and sensation seeking, CABs emerged as the strongest correlate of RSE other than drinking itself, and explained significant additional variance in RSE beyond these other predictors. Mediation analyses revealed that CABs had a significant indirect effect on RSE through typical weekly drinking. This pattern of findings indicates that college alcohol beliefs are, from a public health perspective, dangerous beliefs, that warrant serious consideration in the development of new approaches to college student drinking and its consequences.

Peer Passenger Norms and Pressure: Experimental Effects on Simulated Driving Among Teenage Males.

OBJECTIVE: Serious crashes are more likely when teenage drivers have teenage passengers. One likely source of this increased risk is social influences on driving performance. This driving simulator study experimentally tested the effects of peer influence (i.e., risk-accepting compared to risk-averse peer norms reinforced by pressure) on the driving risk behavior (i.e., risky driving behavior and inattention to hazards) of male teenagers. It was hypothesized that peer presence would result in greater driving risk behavior (i.e., increased driving risk and reduced latent hazard anticipation), and that the effect would be greater when the peer was risk-accepting. METHODS: Fifty-three 16- and 17-year-old male participants holding a provisional U.S., State of Michigan driver license were randomized to either a risk-accepting or risk-averse condition. Each participant operated a driving simulator while alone and separately with a confederate peer passenger. The simulator world included scenarios designed to elicit variation in driving risk behavior with a teen passenger present in the vehicle. RESULTS: Significant interactions of passenger presence (passenger present vs. alone) by risk condition (risk-accepting vs. risk-averse) were observed for variables measuring: failure to stop at yellow light intersections (Incident Rate Ratio (IRR)=2.16; 95% Confidence Interval [95CI]=1.06, 4.43); higher probability of overtaking (IRR=10.17; 95CI=1.43, 73.35); shorter left turn latency (IRR=0.43; 95CI=0.31,0.60); and, failure to stop at an intersection with an occluded stop sign (IRR=7.90; 95CI=2.06,30.35). In all cases, greater risky driving by participants was more likely with a risk-accepting passenger versus a risk-averse passenger present and a risk-accepting passenger present versus driving alone. CONCLUSIONS: Exposure of male teenagers to a risk-accepting confederate peer passenger who applied peer influence increased simulated risky driving behavior compared with exposure to a risk-averse confederate peer passenger or driving alone. These results are consistent with the contention that variability in teenage risky driving is in part explained by social influences.