Abstract:

Adolescents are undoubtedly influenced by their peers, but previous research has predominantly focused on the negative aspects of this influence, such as its impact on aggressive, antisocial, and risky behavior. However, the positive effects of peer influence, particularly on prosocial behavior, have not received the same level of attention. Prosocial behavior, which involves actions that benefit others, is a crucial aspect of positive adolescent development and holds significant importance for their overall well-being. While researchers have recently begun exploring the positive influence of peers, there remains a lack of consensus regarding whether adolescents' prosocial behavior is more influenced by selfless or selfish peers, and the underlying mechanisms remain unclear. Another essential aspect to consider is the influence of different sources of information on adolescents' prosocial behavior. In the context of Chinese culture, where authority and respect hold significant cultural value, adolescents may be more susceptible to the influence of adults than their peers. Comparing the role of authority figures in shaping prosocial behavior can offer valuable cultural insights into social dynamics among Chinese adolescents. Moreover, researchers have identified the belief in a just world (BJW) as a significant factor in moderating the relationship between social cognition and prosocial behavior. However, the specific role of BJW in the context of social influence, especially concerning peer influence on prosocial behavior, remains unexplored. Investigating the interplay between BJW and peer influence can provide a deeper understanding of the psychological processes that drive prosocial behavior in adolescents.
In this study, we utilized an adaptive algorithm and the conflicting source paradigm to examine the influence of social information (prosocial, selfish, conflict) provided by peers or adults on adolescents' donation behavior at a real cost. Additionally, we investigated how the belief in a just world (BJW) factors into this context. The research involved a sample of 77 adolescents aged between 12 and 15 years (with a mean age of 14.06 ± 0.74 years, including 32 girls). As illustrated in Figure 1, each participant was presented with 18 different charity scenarios in a random order. In each scenario, they were given 100 tokens, which they could donate to the charity of their choice. Any remaining tokens could be exchanged for real money after completing the donation task. The study was divided into two phases: In the first phase, participants independently made their initial donation decisions. In the second phase, participants were exposed to the donation choices of two peers or adults. The donation amounts displayed by these peers or adults were either higher or lower than the participants' initial donations, depending on the experimental conditions. This setup allowed us to observe prosocial-influence trials, selfish-influence trials, or conflict-influence trials.
The direction of social influence (prosocial, selfish, conflict), information provider (peer or adult), and decision-making phase (first decision, second decision) were included as within-subjects independent variables in the analysis. We analyzed how social influences affected individual prosocial behavior. A LMM revealed a significant main effect of decision-making rounds, F(1, 2672) = 25.69, p < 0.001. The main effect of the direction of social influence was not significant, F(2, 12) = 3.44, p = 0.066; while the interaction effect between the two was significant, F(2, 2672) = 11.99, p < 0.001, R²_{fixed effect} = 0.56. The simple effect test showed that the second donation, after viewing the others’ decisions, was more generous than the initial donation in both the prosocial (M _second − M _initial = 9.27, p < 0.001) and the conflict conditions (M _second − M _initial = 4.34, p = 0.003), but not in the selfish condition (p = 0.573). This suggests that adolescents are more likely to be swayed by others’ prosocial rather than selfish behaviors. In other words, adolescents were more sensitive to prosocial influence than selfish influence.
In addition, influence magnitude was measured as the extent to which participants altered their donation in line with the observed donations. A LMM showed a main effect of the direction of social influence, F(2, 522) = 30.88, p < 0.001, suggesting that, the change magnitude was largest under the prosocial condition and smallest under the conflict condition (M _{prosocial condition} − M _{conflict condition} = 12.78, p < 0.001; M _{selfish condition} − M _{conflict condition} = 10.72, p < 0.001). The model also showed a main effect of information provider, F(1, 507) = 3.92, p = 0.048, R²_{fixed effect} = 0.33, which indicated that adolescents were more likely to be influenced by information provided by peers than that provided by adults.
We took a closer look at the participants' responses in the conflict condition. As shown in Figure 2, under peer influence condition, 33.33% of the participants made more altruistic second decisions, while only 10.39% shifted towards egoism, with significant difference, χ²(1) = 27.81, p < 0.001. Under adult influence condition, the above proportions were 26.84% and 14.72% respectively, with significant difference, χ²(1) = 8.17, p = 0.004. The McNemar test further revealed that when adolescents encountered both prosocial and selfish information, they were more likely to become more altruistic in their second donations under peer influence than under adult influence, χ²(1) = 15.92, p < 0.001, which indicates that adolescents are more influenced by peer role models than by adult role models.
Lastly, this study explored the role of the belief in a just world (BJW). We found BJW was significantly positively correlated with prosocial behavior (initial donations; r = 0.08, p = 0.002). We also used a hierarchical regression to analyze the moderating effect of BJW on social influence experienced by adolescents. The results showed that the interaction terms of prosocial condition and BJW and the interaction terms of conflict condition and BJW could significantly predict the outcome of second decisions (the former: Β = 3.55, t = 3.15, p = 0.002, 95% CI = [1.34, 5.76]; the latter: Β = 2.84, t = 2.52, p = 0.012, 95% CI = [0.63, 5.05]). The simple slope test showed that for low-BJW individuals, the direction of social influence could significantly predict second decisions under prosocial condition (Β = 6.90, t = 4.07, p < 0.001, LLCI = 3.57, ULCI = 10.23), but not under conflict condition. While for individuals with high BJW, it was a stronger predictor (the prosocial condition: Β = 14.47, t = 8.52, p < 0.001, LLCI = 11.14, ULCI = 17.79, see Figure 3a; the conflict condition: Β = 8.08, t = 4.76, p < 0.001, LLCI = 4.75, ULCI = 11.40, see Figure 3b). Hence, BJW moderated the prosocial influence on adolescents, with those having a higher belief in a just world being more susceptible to positive social influence.
The findings of this study revealed interesting patterns in adolescents' donation behavior under different social influence conditions. Specifically, in both the prosocial and conflict conditions, adolescents exhibited more altruistic second donations compared to their initial donations. Notably, the increase in the amount of the second donation was most significant in the prosocial condition, suggesting that adolescents are particularly receptive to positive influence from their peers. Moreover, the study highlighted that adolescents are more influenced by their peers than by adults. The change in the amount of the second donation was more pronounced when under the influence of peers compared to the influence of adults. This indicates the considerable impact that peer influence can have on adolescents' prosocial behavior.
In conclusion, this research sheds light on the significance of social influence, especially from peers, in encouraging prosocial behavior among adolescents. Leveraging positive peer role models and promoting interactions with altruistic peers can be instrumental in fostering a more compassionate and altruistic community of adolescents, benefiting both individuals and society as a whole.