This investigation examines the spread of problem behaviors (substance use and delinquency) between twin siblings. A sample of 628 twins (151 male twin pairs and 163 female twin pairs) drawn from the Quebec Newborn Twin Study completed inventories describing delinquency and substance use at ages 13, 14, and 15. A 3-wave longitudinal actor-partner…

This article reports on a survey with 170 school-age children growing up with two or more languages in the Canadian province of Ontario where English is the majority language, French is a minority language, and numerous other minority languages may be spoken by immigrant or Indigenous residents. Within this context the study focuses on minority…