This article reviews the multidisciplinary advancements in understanding peer influence processes among adolescents over the past decade. It identifies five key themes: broadening the range of behaviors influenced by peers, distinguishing sources of influence, exploring moderators of influence, testing theoretically based models, and integrating behavioral neuroscience perspectives. The review highlights significant progress in each area, while also identifying gaps and challenges for future research. Key findings include the broadening of peer influence to include behaviors beyond deviant and aggressive acts, the recognition of multiple sources of influence such as romantic partners and larger peer networks, and the exploration of mechanisms like social learning and identity-based theories. The article also discusses moderators such as adolescent characteristics, influencer characteristics, relationship dynamics, and the type of behavior, emphasizing the need for a more nuanced understanding of these factors. Finally, it integrates insights from behavioral genetics and neuroscience, suggesting that biological factors may moderate the influence of peers. The review concludes by highlighting the importance of longitudinal studies and the need to address cultural differences in peer influence processes.This article reviews the multidisciplinary advancements in understanding peer influence processes among adolescents over the past decade. It identifies five key themes: broadening the range of behaviors influenced by peers, distinguishing sources of influence, exploring moderators of influence, testing theoretically based models, and integrating behavioral neuroscience perspectives. The review highlights significant progress in each area, while also identifying gaps and challenges for future research. Key findings include the broadening of peer influence to include behaviors beyond deviant and aggressive acts, the recognition of multiple sources of influence such as romantic partners and larger peer networks, and the exploration of mechanisms like social learning and identity-based theories. The article also discusses moderators such as adolescent characteristics, influencer characteristics, relationship dynamics, and the type of behavior, emphasizing the need for a more nuanced understanding of these factors. Finally, it integrates insights from behavioral genetics and neuroscience, suggesting that biological factors may moderate the influence of peers. The review concludes by highlighting the importance of longitudinal studies and the need to address cultural differences in peer influence processes.