For decades, psychological research has examined the extent to which children's and adolescents' behavior is influenced by the behavior of their peers (i.e., peer influence effects). This review provides a comprehensive synthesis and meta-analysis of this vast field of psychological science, with a goal to quantify the magnitude of peer influence effects across a broad array of behaviors (externalizing, internalizing, academic). To provide a rigorous test of peer influence effects, only studies that employed longitudinal designs, controlled for youths' baseline behaviors, and used "external informants" (peers' own reports or other external reporters) were included. These criteria yielded a total of 233 effect sizes from 60 independent studies across four different continents. A multilevel meta-analytic approach, allowing the inclusion of multiple dependent effect sizes from the same study, was used to estimate an average cross-lagged regression coefficient, indicating the extent to which peers' behavior predicted changes in youths' own behavior over time. Results revealed a peer influence effect that was small in magnitude (β¯ = .08) but significant and robust. Peer influence effects did not vary as a function of the behavioral outcome, age, or peer relationship type (one close friend vs. multiple friends). Time lag and peer context emerged as significant moderators, suggesting stronger peer influence effects over shorter time periods, and when the assessment of peer relationships was not limited to the classroom context. Results provide the most thorough and comprehensive synthesis of childhood and adolescent peer influence to date, indicating that peer influence occurs similarly across a broad range of behaviors and attitudes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

中文翻译：

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儿童和青春期纵向同伴影响效应的荟萃分析。

几十年来，心理学研究检查了儿童和青少年的行为在多大程度上受到同龄人行为的影响（即同龄人影响效应）。这篇综述对这一庞大的心理科学领域进行了全面的综合和荟萃分析，目的是量化同伴影响对广泛行为（外化、内化、学术）的影响程度。为了提供对同伴影响效应的严格测试，只纳入了采用纵向设计、控制青少年基线行为并使用“外部线人”（同伴自己的报告或其他外部报告者）的研究。这些标准从四个不同大陆的 60 项独立研究中产生了总共 233 个效应量。多层次元分析方法，允许包含来自同一研究的多个相关效应大小，用于估计平均交叉滞后回归系数，表明同龄人的行为预测青少年自身行为随时间变化的程度。结果显示，同伴影响效应的幅度很小 (β¯ = .08)，但显着且稳健。同伴影响效应不随行为结果、年龄或同伴关系类型（一个密友对多个朋友）而变化。时间滞后和同伴背景成为重要的调节因素，表明在较短的时间段内，同伴影响效应更强，并且当同伴关系的评估不限于课堂环境时。结果提供了迄今为止对儿童和青少年同伴影响的最彻底和全面的综合，表明同伴影响在广泛的行为和态度中同样发生。（PsycInfo 数据库记录 (c) 2021 APA，保留所有权利）。