The companions in crime hypothesis suggests that co-offending moderates the link between peer delinquency and adolescent delinquency. However, this hypothesis has rarely been investigated longitudinally. Hence, this study investigated the co-development of friends’ delinquency and adolescents’ delinquency, as well as the co-development of friends’ delinquency and short-term mindsets (impulsivity and lack of school future orientation). Whether this co-development is stronger when adolescents engage in co-offending was also investigated. Three data waves with two year lags from an ethnically-diverse adolescent sample (at wave 1: N = 1365; 48.6% female; M_age = 13.67; age range = 12.33–15.09 years) in Switzerland were used. The results from parallel process latent growth modeling showed that the co-development between friends’ delinquency and adolescents’ delinquency was stronger when adolescents engaged in co-offending. Thus co-offending likely provides direct access to a setting in which adolescents continue to model the delinquency they learned with their peers.

犯罪假说的同伴认为，共同犯罪可减轻同伴犯罪和青少年犯罪之间的联系。但是，这种假说很少进行纵向研究。因此，本研究调查了朋友犯罪和青少年犯罪的共同发展，以及朋友犯罪和短期心态（冲动性和缺乏学校未来取向）的共同发展。还研究了青少年参与共同犯罪时这种共同发展是否更强。来自不同种族的青少年样本的三年数据滞后两波（在波1：时N  = 1365;女性48.6％; M_年龄 = 13.67; 在瑞士使用的年龄范围= 12.33–15.09岁。并行过程潜在增长模型的结果表明，当青少年参与共同犯罪时，朋友的犯罪和青少年的犯罪之间的共同发展会更强。因此，共同犯罪可能直接提供一种环境，在这种环境中，青少年继续模拟他们与同龄人学到的犯罪行为。