Nonshared environmental mediation of the association between deviant peer affiliation and adolescent externalizing behaviors over time: Results from a cross-lagged monozygotic twin differences design.

Abstract

It has been argued that peers are the most important agent of adolescent socialization, and more specifically, that this socialization process occurs at the child-specific (or non-shared environmental) level (Harris, 1998;Plomin & Asbury, 2005). The present study sought to empirically evaluate this non-shared environmental peer influence hypothesis, examining the association between externalizing behaviors and deviant peer affiliation in a sample of 454 pairs of monozygotic (genetically identical) twins, assessed at ages 14 and 17, within a cross-lagged twin differences design. Results argued against a causal non-shared environmental influence of peer affiliation on the development of externalizing behaviors, and in favor of non-shared environmental "selection". In particular, the twin with more externalizing behaviors at age 14 reported increased deviant peer affiliation relative to his or her co-twin three years later, regardless of one's genetic predispositions towards externalizing behavior. Such findings suggest that adolescents with higher levels of externalizing behaviors select or shape (either intentionally or inadvertently) subsequent environmental experiences to involve increased affiliation with deviant peers. Implications are discussed. KeywordsDeviant peer groups; Non-shared environmental influences; Twin Differences; Externalizing behaviors In her 1998 book entitled "The Nurture Assumption", Judith Harris provocatively suggested that peers (and not parents) were the primary environmental agents of adolescent socialization. Her theory was based largely on behavioral genetic findings highlighting the very limited involvement of the shared environment (i.e., family-level environmental influences that increase similarity between siblings), as well as the prominent influence of both genetic and non-shared environmental effects (i.e., child-specific environmental influences that serve to make siblings different from one another). She specifically postulated that, because peers are not typically shared by siblings, peers were the most obvious causal source of these large nonshared environmental influences (Harris, 1998).Correspondence: Address correspondence to Alex Burt, Department of Psychology, Michigan State University, 107D Psychology Building, East, Lansing, MI, 48824. Electronic mail may be sent to, burts@msu.edu. Phone and fax numbers are 517-432-5602 and, 517-432-2476, respectively. NIH Public Access Author ManuscriptDev Psychol. Author manuscript; available in PMC 2010 November 1. Published in final edited form as:Dev Psychol. 2009 November ; 45(6): 1752-1760. doi:10.1037/a0016687. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptThis theory initially spawned a great deal of criticism (Collins, Maccoby, Steinberg, Hetherington, & Bornstein, 2000;Vandell, 2000), though chiefly in defense of the role of parents in offspring socialization. Indeed, subsequent research has generally not supported the contention that parenting does not matter. For example, behavio...

Links between friends’ physical aggression and adolescents’ physical aggression

“…However, when using the twins as singletons, a moderate effect of friends' physical aggression on changes in twins' physical aggression was found. These results are in line with other studies using the MZ-twin difference method, which also found no predictive effect of friends' antisocial behavior on participants' own antisocial behavior (Beaver, 2008;Burt et al, 2009;Hou et al, 2013). They are also in line with recent findings by TenEyck and Barnes (2015) showing that friends' deviance is correlated with participants' deviance before, but not after, controlling for genetic factors.…”

“…There is also evidence to show that affiliation with physically aggressive friends contributes to this process, partly by amplifying early physical aggression through coercion or through deviancy training (Dishion, Andrews, & Crosby, 1995;Snyder et al, 2005;Vitaro, Pedersen, & Brendgen, 2007). This evidence is in line with behavioral genetic studies showing that an important portion of variance with respect to physical aggression is influenced by non-shared environmental factors (i.e., factors that are not shared among siblings and that make siblings, including twins, different from each other) (Burt, McGue, & Iacono, 2009). It has been suggested that friends are among the most important non-shared environmental influences in children's and adolescents' lives (Harris, 1998).…”

Neurocognitive Deficits in Attention-Deficit/Hyperactivity Disorder With and Without Comorbid Oppositional Defiant Disorder

“…For working memory, recent meta-analyses showed large working memory deficits for children with ADHD that persist into adulthood (Alderson, Kasper, Hudec, & Patros, 2013; Kasper, Alderson, & Hudec, 2012). Studies in ADHD + ODD groups are scarce and report both absence and presence of working memory abnormalities (Burt, McGue, & Iacono, 2009; Hicks, South, Dirago, Iacono, & McGue, 2009; Saarinen, Fontell, Vuontela, Carlson, & Aronen, 2015; Walden, McGue, Lacono, Burt, & Elkins, 2004). Only two studies investigated working memory in ODD and found the disorder to be associated with a working memory deficit (Rhodes, Park, Seth, & Coghill, 2012; Sergeant et al, 2002).…”

A Longitudinal Investigation of the Associations Among Parenting, Deviant Peer Affiliation, and Externalizing Behaviors: A Monozygotic Twin Differences Design

“…Modeling analyses were conducted on signed sibling differences, allowing us to evaluate the direction of any significant effects. For example, a positive cross-lagged coefficient suggests that the twin with more of one trait evidences more of the other (see Burt et al, 2009). Note: M = mother; F = father; EXT_T1 and T2 = externalizing symptoms at the T1 and T2 assessments; Peer_T1 and T2 = deviant peer affiliation at the T1 and T2 assessments.…”