The second goal of this study was to determine whether adolescents would report a greater likelihood to engage in behaviors endorsed by an attractive opposite-sex peer than their original independent report. We hypothesized that 1) adolescents who demonstrated an increased ventral striatal response to peer feedback would be more susceptible to experimentally manipulated peer influence; 2) self reported peer influence would be associated with experimentally manipulated peer influence; and 3) adolescents would report a greater likelihood to partake in risky behaviors after viewing an attractive opposite-sex peer’s “responses.”In the questionnaires administered during Study 2, participants completed self report surveys that assessed their resistance to peer influence and likelihood to use substances.Participants were posed with two opposing situations and asked to indicate which one best represented them. For example, one item reads: “For some people, it’s pretty easy for their friends to get them to change their mind.” OR “For other people, it’s pretty hard for their friends to get them to change their mind.” Items were scored on a 4-point scale, with a higher score indicating greater resistance to peer influence; individual composite scores were created by averaging items that were associated with fitting in,greenhouse racking going along with a crowd, changing their mind, engaging in bad behavior, and hiding their opinion.
An overall composite score was calculated by averaging all ten items. The Likelihood to Take Risks Questionnaire was administered along with the Drug Use Inventory—Revised and Ontario Student Drug Use and Health Survey . Between answering questions about their actual substance use, participants were asked about their likelihood to engage in substance use activities, risk-taking activities, and prosocial activities . A sample item included “If you were given an opportunity to use alcohol, how likely would you be to use it?” Participants responded on a Likert scale from 1 to 7 . Responses were recoded and rescored . Following presentation of the mock data, participants responded to filler questions about their engagement in other activities along with the same likelihood questions administered in Study 2.All participants changed at least one of their responses in the post-peer influence manipulation questionnaire. Across all items, 36.84% of participants reported a greater likelihood to engage in behaviors, 63.16% of participants reported a decreased likelihood to engage in behaviors post-manipulation. Between the categories of questions in the questionnaire, we found that 26.32% of participants reported an increased likelihood to use substances, 57.89% of participants reported a decreased likelihood to use substances, and 15.79% of participants reported no change in likelihood to use substances following the peer influence manipulation. Of the questions pertaining to risk-taking, 15.79% of participants reported a greater likelihood to take risks, 31.58% of participants reported a decreased likelihood to take risks, and 47.37% of participants reported no change in likelihood to take risks following the peer influence manipulation.
Of the questions pertaining to antisocial behaviors, no participants reported an increased likelihood to engage in antisocial behaviors, 36.84% of participants reported a decreased likelihood to engage in antisocial behaviors, and 57.89% of participants reported no change in likelihood to engage in antisocial behaviors following the peer influence manipulation. Of the questions pertaining to prosocial behaviors, 42.11% of participants reported an increased likelihood to engage in prosocial behaviors, 21.05% of participants reported a decreased likelihood to engage in prosocial behaviors, and 36.84% of participants reported no change in likelihood to engage in prosocial behaviors following the peer influence manipulation . Between the groups of substances participants were surveyed on, we found 26.32% of participants reported an increased likelihood to use Group I substances , 21.05% of participants reported a decreased likelihood to use Group I substances, and 52.63% of participants reported no change in likelihood to use Group I substances following the peer influence manipulation. Of the questions pertaining to Group II substance use medication , pain killers, psilocybin, we found 15.79% of participants reported an increased likelihood to use Group II substances, 47.37% of participants reported a decreased likelihood to use Group II substances, and 36.84% of participants reported no change in likelihood to use Group II substances following the peer influence manipulation. Of the questions pertaining to Group III substance use , cocaine, we found 15.79% of participants reported an increased likelihood to use Group III substances, 21.05% of participants reported a decreased likelihood to use Group III substances, and 63.15% of participants reported no change in likelihood to use Group III substances following the peer influence manipulation.
Of the questions pertaining to Group IV substance use , heroin, Lysergic acid diethylamide, 5.26% of participants reported an increased likelihood to use Group IV substances, 5.26% of participants reported a decreased likelihood to use Group IV substances, and 89.47% of participants reported no change in likelihood to use Group IV substances following the peer influence manipulation .Bivariate correlational analyses were performed to determine if there were associations between neural responses to violations of expectations in Study 1, and RPI, and pre- and post peer influence manipulation responses to the Likelihood to Take Risks Questionnaire in Study 3. This analysis revealed a significant association between self-reported happiness in Study 1 when expectations were violated to going along with the crowd in the RPI measure, such that participants who were happier upon experiencing a violation of expectations were less resistant to peer influence and more likely to go along with the crowd r = – .52, p = .023. Participants who were happier when expectations were met were also less resistant to peer influence and more likely to go along with the crowd r = – .61, p = .005. Participants who demonstrated increased ventral striatal response to violations of expectations were more resistant to peer influence in hiding their opinion r = .61, p = .006. Participants who demonstrated increased ventral striatal response when expectations were met were less resistant to peer influence in fitting in with others r = -.61, p = .006 and demonstrated an increase in their likelihood to use Group I substances following the peer influence manipulation r = .53, p = .019. Participants who were less resistant to peer influence in fitting in with others demonstrated an increase in their likelihood to use Group I substances following the peer influence manipulation r = -.69, p < .001 . Participants who were less resistant to peer influence in engaging in wrongful behaviors demonstrated an increase in their likelihood to engage in risk-taking following the peer influence manipulation r = -.71, p = .001. Participants who were less resistant to peer influence demonstrated an increase in likelihood to use Group II substances following the peer influence manipulation r = -.68, p = .001 . All correlational analyses are depicted in Table 3.1.The goal of this study was to determine whether self-reported susceptibility to peer influence was associated with experimentally manipulated peer influence, and associate ventral striatal activation in response to violations of expectations with susceptibility to peer influence. We found that participants modified their responses following the peer influence manipulation. Additionally,indoor cannabis grow system we found self-reported susceptibility to peer influence was associated with experimentally manipulated peer influence. We also found that participants who demonstrated increased ventral striatum activation in response to experiencing a violation of expectations were more likely to share their opinions with their friends, as indicated in the Resistance to Peer Influence questionnaire. To our knowledge, our study is the first to validate this measure with an experimental manipulation pertaining to real-world behaviors in an adolescent sample. Specifically, we found that participants who were more susceptible to peer influence with regard to fitting in with others reported an increase in likelihood to use Group I substances following the peer influence manipulation. Reports on adolescent substance use indicate that adolescents use more Group I substances than other substances and are more likely to try these types of substances if they are susceptible to peer influence . We posit that adolescents who are eager to fit in with other peers are likely to consider engagement in socially acceptable behaviors they believe their peers engage in , which in this study, resulted in reporting a likelihood to use socially acceptable substances. This echoes previous literature suggesting adolescents are likely to use substances if a well liked or high status peer is using substances .
This suggests that explicit peer influence is not necessary for adolescents to modify their behavior; instead, subtly providing information may be sufficient for adolescents to reconsider their own likelihood to engage in risky behaviors. We expect that in accordance with the literature, if adolescents’ own friends endorsed socially acceptable substance use, adolescents would also endorse using substances . We found that adolescents who were susceptible to peer influence reported an increased likelihood to engage in risky behaviors—such as using Group II substances following the peer influence manipulation. Previous research has indicated that adolescents who are likely to use these types of substances are susceptible to peer influence and may also have low self-esteem , be rejected or bullied by other peers , have greater access to these types of substances , and may be more likely to take risks — all of which may be moderators of likelihood to use substances that have greater consequences and are less socially acceptable than alcohol, tobacco, or cannabis. Additionally, we found participants who had decreased self-reported happiness when they received social feedback from Study 1 were more likely to go along with the crowd—as measured by the Resistance to Peer Influence questionnaire, perhaps because unhappy adolescents preferred to rely upon others rather than risk rejection and experience additional unhappiness. We suggest future research disentangle the mechanisms that lead adolescents to considering socially acceptable substance use compared to socially unacceptable/illegal substance use. All participants modified their responses to the Likelihood to Take Risks questionnaire following the peer influence manipulation. This result is the first to replicate that of the study by Allen and colleagues , whereby adolescents modified their responses after viewing a peer’s responses. However, upon further examination, we found that rather than reporting a greater likelihood to engage in risky behaviors, in general, adolescents reported a decreased likelihood to engage in risky behaviors following the peer influence manipulation. We suspect that viewing an opposite-sex peer’s responses led participants to respond more conservatively than they reported prior to the peer influence manipulation because they may have been concerned another peer was going to view their data . Thus, they may have been more eager to shield their actual behaviors rather than endorse riskier behaviors, fearing judgment . There were gender differences in response to peer influence manipulation, where males reported a decrease in likelihood to engage in substance use, females endorsed an increase in likelihood to engage in substance use. We suspect participants responded in a fashion that was more aligned with how they expected a peer of the opposite-sex to respond—in this case, less risky for males, and riskier for females . Interestingly, this difference did not extend beyond substance use. Research has suggested that adolescents perceive out-group others as using substances differently than they do , though it is unclear whether this extends to other types of risk-taking. Given the prevalence of Group I substance use presented to participants compared to the other risks, it may be the case that modifying that behavior was due to the salience of that item compared to the others. We also found participants were less likely to engage in antisocial behaviors following the peer influence manipulation. We suspect that the image of an attractive peer was a cue that became salient to the participant during the post-manipulation, and participants were less inclined to report being likely to engage in antisocial behaviors, as researchers have demonstrated that viewing an image of a peer encourages people to be prosocial.Participants who demonstrated increased ventral striatum activation reported they would share their opinion with peers.Researchers have posited that adolescents who recruit the ventral striatum are also motivated by reward and social feedback.We suggest participants who reported being bold enough to voice their opinions to their peers were eager to test their social climate and found reward in receiving social feedback —thereby demonstrating greater ventral striatum activation. While our study has many notable strengths, we acknowledge its weaknesses— specifically, our small sample size.