Integration into formal and informal peer groups is a key developmental task during early adolescence. As youth begin to place greater value on attaining acceptance and popularity among peers, social status among one’s peer group becomes an important marker of social functioning during this developmental period. Whereas much empirical research has been devoted to understanding heterogeneity among youth holding high status positions, similar distinctions have largely not been examined among socially marginalized youth. The present study sought to address this gap in the research by examining the extent to which two aspects of social marginalization, peer rejection and social network isolation, were differentially associated with trajectories of social and behavioral adjustment across two school years in early adolescence. Peer nominations were used to assess rejection, isolation, and the behavioral outcomes of interest (i.e., aggression, internalizing behaviors, and victimization), and participants self-reported the extent to which peers would come to their aid in bullying situations (i.e., peer protection from bullying). Using a longitudinal sample of early adolescents (n = 1075; 53.0% female; 47.2% White; 27.1% African American; 12.7% Hispanic) in grades 5 through 7, preliminary analyses revealed little overlap between rejection and isolation at each time point. Moreover, a series of multilevel models revealed that rejection and isolation were associated with somewhat distinct behavioral and social adjustment trajectories. Peer rejection was positively associated with peer-nominated aggression, both within and across time points, and negatively associated with prosocial behaviors. Conversely, isolation was positively associated with peer-nominated internalizing behaviors, both within and across time points. Rejection and isolation were each positively associated with peer nominations of victimization; however, only isolation was related to lower perceptions of peer protection from bullying. In general, support was found for assessing rejection and isolation as two distinct forms of social marginalization in early adolescence.

融入正式和非正式的同伴群体是青春期早期的一项关键发展任务。随着年轻人开始更加重视获得同龄人的接受和受欢迎程度，同龄人中的社会地位成为这一发展时期社会功能的重要标志。尽管许多实证研究都致力于了解处于高地位的青年之间的异质性，但在社会边缘化青年中，类似的区别基本上没有得到研究。本研究试图通过检查社会边缘化、同伴排斥和社交网络孤立这两个方面与青春期早期两个学年的社会和行为调整轨迹的不同程度相关来解决研究中的这一差距。同伴提名被用来评估拒绝、孤立和感兴趣的行为结果（即攻击性、内化行为和受害），参与者自我报告同伴在欺凌情况下会帮助他们的程度（即同伴防止欺凌）。使用早期青少年的纵向样本（n = 1075; 53.0% 女性；47.2% 白色；27.1% 非裔美国人；12.7% 西班牙裔）在 5 至 7 年级，初步分析显示拒绝和隔离在每个时间点之间几乎没有重叠。此外，一系列多层次模型表明，拒绝和孤立与有些不同的行为和社会适应轨迹有关。同伴拒绝与同伴提名的攻击行为在时间点内和跨时间点呈正相关，而与亲社会行为呈负相关。相反，孤立与同伴提名的内化行为正相关，无论是在时间点内还是跨时间点。拒绝和孤立都与受害的同伴提名呈正相关；然而，只有孤立与对同伴保护免受欺凌的看法较低有关。一般来说，