Age-related differences in friend similarity of delinquent behavior

During a period of increased independence from parents, youth turn to peers for support, and consequently become more vulnerable to peer pressure (Steinberg & Silverberg, 1986). During middle adolescence, vulnerability to peer influence begins to decline (Steinberg & Monahan, 2007). Empirical research has documented this trend in vulnerability to peer pressure across adolescence, but less attention has been afforded to the age-related changes in similarity. To address this, age-related changes in peer similarity in delinquency across the adolescent years were examinded using intraclass correlations. Moderating variables, including gender, reciprocity, and closeness, and control variables, including friendship stability and romantic partner status, were examined. Results indicated an increase in friend similarity in delinquency from 5th to 7th grade and a decrease in similarity from 7th to 9th grade. Implications of this study are discussed in terms of contribution to the field and implementation of the findings.