关键词: 亲社会行为, 同伴拒绝, 多巴胺系统基因×环境, 发展轨迹, 平行潜增长模型

Abstract: Prosocial behavior—behaviors intended to benefit others—is of particular importance to the development of children’s psychosocial functioning and has been a popular topic of research recently. Adolescence is a critical period for facilitating prosocial behavior and internalizing prosocial values because the ecological and biological transitions during adolescence play an important role in the development of prosocial behavior. Particularly, peer group changes and the increasing importance of peer relationships during this period provide both risks and opportunities for the development of prosocial behaviors. Moreover, individuals vary widely in their sensitivity to peer context. Recent evidence indicated that the genes involved in dopamine neurotransmission and metabolism act in an additive manner to influence sensitivity to the environment. It would be expected that dynamic changes in prosocial behavior over time would be related to both changing levels of peer environment and the person’s genetic predisposition. However, to our knowledge, no studies have investigated how dopaminergic genes and peer relationships interact to predict changes in prosocial behavior over time among adolescents. Therefore, the present study aimed to explore the dynamic trajectory of the relationship between peer rejection and prosocial behavior, and whether the dynamic association was moderated by dopaminergic genes. Participants were 1044 adolescents who were followed from age 13 to 15 (mean age 13.32 ± 0.48 years old at Time 1, 50.1% females). Adolescents’ saliva samples were collected at age 13. Saliva samples, peer-rated prosocial behavior, and peer-nomination peer rejection were collected. All measures showed good reliability. Genotyping was performed for each participant in real-time with MassARRAY RT software version 3.0.0.4 and analyzed using the MassARRAY Typer software version 3.4 (Sequenom). The parallel latent growth model and multiple group comparison analyses were used to examine the relationship between the developmental trajectories of peer rejection and prosocial behavior and the moderating role of dopaminergic genes. The results showed that adolescents’ prosocial behavior and peer rejection increased linearly during the follow-up period. Higher initial levels of peer rejection were associated with lower initial levels and slower growth of prosocial behavior. The change rates of peer relationships were associated with the developmental change of prosocial behavior, that is, the slower increase in peer rejection was associated with a greater increase in prosocial behavior over time. In addition, the relationships between the initial level of peer rejection and the initial level and growth in prosocial behavior were moderated by MGPS, with lower MGPS being more sensitive to the initial level of peer rejection. These findings lend support to the dynamic relationship between peer relationships and prosocial behavior and shed light on the complex polygenic underpinnings of prosocial behavior.

Key words: prosocial behavior, peer rejection, dopaminergic genes × environment, developmental trajectories, parallel latent growth modeling