Social influence in adolescence: Behavioral and neural responses to peer and expert opinion

Social influence plays a crucial role during the teen years, with adolescents supposedly exhibiting heightened sensitivity to their peers. In this study, we examine how social influence from different sources, particularly those with varying normative and informational significance, affect adolescents' opinion change. Furthermore, we investigated the underlying neural dynamics to determine whether these two behaviorally similar influences share their neural mechanisms. Twenty-three participants (14-17 years old) gave their opinions about facial stimuli and received feedback from either a peer group or an expert group, while brain responses were recorded using concurrent magnetoencephalography. In a second rating session, we found that participants' opinions changed in line with conflicting feedback, but only when the feedback was lower than their initial evaluation. On the neural level, conflict with peers evoked stronger neural responses than conflict with experts in the 230-400 ms time window and the right frontotemporal magnetometer channels. Nevertheless, there was no greater conformity toward peers. Moreover, conflict compared to no conflict decreased neural oscillations in the beta frequency range (20-26 Hz) at the right frontal and parietal channels. Taken together, our findings do not support the general assumption that adolescent behavior is excessively vulnerable to peer norms, although we found heightened neural sensitivity to peer feedback.

The effect of descriptive norms and social identification on performance and exertion during a physical fitness task

Research suggests that people's perceptions of the typical physical activity behaviors of others-descriptive norms-shape their own physical activity. However, prior work has primarily used cross-sectional designs, focused on people's physical activity intentions or self-reported overall physical activity, and failed to attend to how the normative referent affects the norm-behavior relationship. In a pre-registered experiment, we manipulated the descriptive norm to explore its effect on perceived exertion during, and objectively assessed performance on, an exercise (running) task. We also measured the strength of participants' social identification as a member of the norm reference group as a potential moderator. Following a baseline trial, participants (N = 78) were either told that their baseline score on the running task was below average (high norm condition) or above average (low norm condition) compared to members of the reference group. Participants in both conditions tended to perform better in Trial 2 than Trial 1. However, participants in the high norm condition improved their performance significantly (2.5 times) more than participants in the low norm condition. Social identification moderated the effect of the norm manipulation on perceived exertion. High identifiers tended to exert themselves less than low identifiers during Trial 2 if they were told they were above average, whereas if told they were below average, high identifiers exerted themselves slightly more than low identifiers. Results provide evidence that descriptive norm messages can improve people's performance on physically demanding tasks, and indicate that descriptive physical activity norms may be more influential when the norm reference group is subjectively meaningful. Opportunities to fruitfully deploy norm messages in applied contexts are discussed.

The Motivational Underpinnings of Intentions to Use Doping in Sport: A Sample of Young Non-Professional Athletes

Doping use is considered as a deviant behavior in sport contexts, and it is necessary to recognize preventive factors to shut down the negative consequences. We proposed that athletes experiencing loss of personal significance would be more prone to doping use intentions. This pathway should occur through the effect of the enhanced predominance of obsessive (vs. harmonious) passion that such athletes experience concerning their sport activity, which, in turn, facilitates the adoption of moral disengagement strategies to find justifications for it, when they perceive that significant others approve their intention. The study relied on a cross-over design, with a convenience sample of 437 athletes recruited at four sports sciences Universities evenly distributed in Italy. Questionnaires administered contained a validated tool based on Kruglanski’s theorizing on radical and deviant behavior (e.g., Loss of Significance, Obsessive, and Harmonious passion) and deriving from social cognitive theory (e.g., Moral disengagement). Results of the study tested a serial mediation moderated model, which links the different variables to explain the influence they have on the intentions to use doping. Overall, this research suggests a motivational dynamic that may be at the heart of illicit behaviors in sport, such as using drugs-enhancing performance potentially among athletes of all kinds.

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.

'If they do it, so can I': a test of a moderated serial mediation model of descriptive norms, self-efficacy, and perceived similarity for predicting physical activity

OBJECTIVE

Though engaging in physical activity (PA) is associated with several health benefits, physical inactivity rates remain high. Previous research revealed that descriptive norms (i.e., perceptions of others' PA) positively relate to PA intentions/behaviours. This study tested whether self-efficacy mediated the influence of descriptive norms on PA intentions and behaviours, and whether the relationship between descriptive norms and self-efficacy was moderated by perceived similarity with normative referents.

DESIGN

Online questionnaires were administered.Measures: Baseline measures included descriptive norms, perceived similarity, self-efficacy, and PA intentions. Weekly PA behaviour frequency was assessed at baseline and two weeks post-baseline.

RESULTS

Descriptive norms positively predicted PA behaviour frequency at time 2 indirectly via self-efficacy and PA intentions. These indirect effects were attenuated when baseline PA behaviour frequency was accounted for. There was no support for perceived similarity as a moderator, which may be attributed to a potential ceiling effect or the nature of items used to assess this perception.

CONCLUSION

The findings support the notion that individuals may feel more efficacious when they perceive that others are successfully engaging in the targeted task/activity. Future interventions may consider providing descriptive norm messages to individuals who lack self-efficacy or previous PA experience to promote their PA.

The Role of Social Norms in the Portion Size Effect: Reducing Normative Relevance Reduces the Effect of Portion Size on Consumption Decisions

People typically eat more from large portions of food than from small portions. An explanation that has often been given for this so-called portion size effect is that the portion size acts as a social norm and as such communicates how much is appropriate to eat. In this paper, we tested this explanation by examining whether manipulating the relevance of the portion size as a social norm changes the portion size effect, as assessed by prospective consumption decisions. We conducted one pilot experiment and one full experiment in which participants respectively indicated how much they would eat or serve themselves from a given amount of different foods. In the pilot (N = 63), we manipulated normative relevance by allegedly basing the portion size on the behavior of either students of the own university (in-group) or of another university (out-group). In the main experiment (N = 321), we told participants that either a minority or majority of people similar to them approved of the portion size. Results show that in both experiments, participants expected to serve themselves and to eat more from larger than from smaller portions. As expected, however, the portion size effect was less pronounced when the reference portions were allegedly based on the behavior of an out-group (pilot) or approved only by a minority (main experiment). These findings suggest that the portion size indeed provides normative information, because participants were less influenced by it if it communicated the behaviors or values of a less relevant social group. In addition, in the main experiment, the relation between portion size and the expected amount served was partially mediated by the amount that was considered appropriate, suggesting that concerns about eating an appropriate amount indeed play a role in the portion size effect. However, since the portion size effect was weakened but not eliminated by the normative relevance manipulations and since mediation was only partial, other mechanisms may also play a role.