Sibling influence on Mexican-origin adolescents' deviant and sexual risk behaviors: The role of sibling modeling

Purpose: A growing body of research indicates that siblings uniquely influence each other's health risk behaviors during adolescence and young adulthood. Mechanisms underlying these associations, however, are largely unknown because they are rarely tested directly. The present study addressed this gap by examining the role of sibling modeling in explaining changes in Mexican-origin youths' deviant and sexual risk behaviors over time. Methods: The sample included 380 Mexican-origin siblings (older sibling age: M = 21.18, SD = 1.59; younger sibling age: M = 18.19, SD =.46) from (N = 190) families. Participants provided self-reports of their sibling relationship qualities, including modeling, as well as their engagement in deviant and sexual risk-taking behaviors in two home interviews across a 2-year span. Results: A series of residualized regression models revealed that younger siblings' perceptions of modeling moderated the links between older siblings' deviant and sexual risk behaviors and younger siblings' subsequent behaviors in those same domains. Specifically, high levels of modeling predicted stronger associations between older siblings' earlier and younger siblings' later risk behaviors controlling for younger siblings' earlier behaviors as well as variables that have been used as proxies for social learning in previous research. Conclusions: Social learning mechanisms, especially modeling, are salient processes through which older siblings transmit norms and expectations regarding participation in health risk behaviors. Future research should continue to explore the ways in which siblings influence each other because such processes are emerging targets for intervention and prevention.