Based on social control perspectives and results from prior studies we test hypotheses about the extent to which characteristics of family and social networks are associated with substance use disorders (SUD), and whether these associations vary by sex. In this study SUD is alcohol or illicit drug abuse or dependence as defined by criteria of the Diagnostic and Statistical Manual of the American Psychiatric Association. With nationally representative data of adult Latinos from the National Latino and Asian American Survey (NLAAS), we found that respondents' language use with family, rather than language proficiency, appears to be a more efficient proxy for social assimilation to represent differential levels of risk of SUD. SUD was positively associated with problematic family relations for men but not women, and SUD was positively associated with more frequent interactions with friends for women but not men. The results suggest that the salient features of social assimilation associated with SUD include the context of language use and transformations in family and social network relationships that differ in important ways between Latino men and women.A substantial body of epidemiologic studies confirms a central conclusion about substanceuse patterns among Latinos in the U.S.: Latinos whose birthplace was outside the U.S. have lower rates of substance abuse and dependence than do Latinos born in the U.S. (Alegría, Canino, Stinson, & Grant., 2006;Amaro, Whitaker, Coffman, & Heeren, 1990;Boles, Casas, Furlong, Gonzalez, & Morrison, 1994;Burnam, Hough, Karno, Escobar, & Telles, 1987;Canino, Burnam, & Caetano, 1992;Grant et al., 2005;Ortega, Rosenheck, Alegría, & Desai, 2000;Turner & Gil, 2002;Vega, Alderete, Kolody, & Aguilar-Gaxiola, 1998a). Additional support for this conclusion comes from multiple international studies, including those conducted in Latin America, showing consistently lower national prevalence estimates for past Despite consistent differences in SUD between U.S.-born and foreign-born Latinos, reasons for the nativity effect are not well understood. One likely explanation is that those born abroad experience lower risk because socialization about alcohol and drug use within family and social networks is linked to strong social control against substance abuse, and immigrants carry these internalized controls with them into the U.S. Antonucci and Akiyama (1987) noted that immigrants rely on a "convoy" model to sustain cultural continuity, using families and extended social networks as agents to preserve prescribed and proscribed behaviors. Consequently, risk for SUD is heightened when there are disruptions in cultural continuity. A range of theories have been developed to explain culture change processes in general, relying on concepts of acculturation and assimilation (e.g., Alba & Nee, 2003;Berry, 1980;Gordon, 1964; Rumbaut, 1994; Vega, Gil, Wartheit, Zimmerman, & Apospori, 1993), which are challenging to operationalize.Critiques have been made regarding the exclusive reliance on accultu...