Regular Article Childhood maltreatment affects adolescent sensitivity to parenting and close friendships in predicting growth in externalizing behavior Irene Tung, Amanda N. Noroña and Steve S. Lee Department of Psychology, University of California, Los Angeles Abstract Childhood maltreatment robustly predicts adolescent externalizing behaviors (EB; e.g., violence, delinquency, substance use) and may crys- talize patterns of EB by influencing sensitivity to the social environment (e.g., parenting, friendships). In a nationally representative sample of 9,421 adolescents, we modeled latent growth curves of EB from age 13 to 32 years. Next, we explored whether maltreated youth differed from nonmaltreated youth in their sensitivity to parental closeness, friendship involvement, and polymorphisms from dopamine genes linked to EB (dopamine receptors D2 and D4, dopamine transporter). Overall, maltreated youth had significantly higher levels of EB across adolescence and adulthood; however, maltreated and nonmaltreated youth showed similar patterns of EB change over time: violent behavior decreased in adolescence before stabilizing in adulthood, whereas nonviolent delinquency and substance use increased in adolescence before decreasing in the transition to adulthood. Maltreatment reduced sensitivity to parental closeness and friendship involvement, although patterns varied based on type of EB outcome. Finally, none of the environmental effects on EB were significantly moderated by the dopamine polygenic risk score after accounting for multiple testing. These findings underline the enduring effects of early maltreat- ment and implicate that maltreatment may contribute to long-term risk for EB by influencing children’s sensitivity to social relationship factors in adolescence. Key words: adolescent development, childhood maltreatment, environmental sensitivity, externalizing behavior (Received 16 September 2017; revised 14 February 2018; accepted 18 April 2018) Externalizing behavior (EB), including violence, nonviolent delin- quency (e.g., stealing), and substance abuse, is one of the costliest public health problems in North America (Foster & Jones, 2005; Welsh et al., 2008). Individual differences in EB are highly sensi- tive to development, including a precipitous increase during ado- lescence (Moffitt, 1993). Ranging from daily interactions with parents and friends (Sentse & Laird, 2010) to severe stressors such as maltreatment (Jaffee, Caspi, Moffitt, & Taylor, 2004; Oshri, Rogosch, Burnette, & Cicchetti, 2011), social experiences affect EB trajectories, which are further affected by genetic varia- tion (Bakermans-Kranenburg & van IJzendoorn, 2011). Transient and mild EB may be normative in adolescence, reflecting identity formation and pursuit of social status (Brezina & Piquero, 2007; Englund et al., 2013; Roisman, Monahan, Campbell, Steinberg, & Cauffman, 2010); however, EB persists for a sizable minority of youth (Evans, Simons, & Simons, 2016; Moffitt, 1993), predict- ing antisocial personality disorder, alcohol/substance use disor- ders, and economic instability (Brown et al., 2008; Maughan et al., 2004; Moffitt & Caspi, 2001). Given its clinical and public health significance, identifying modifiable predictors of EB growth and desistance from adolescence to adulthood is necessary to design effective prevention programs. Maltreatment and EB One of the most consistent and robust predictors of EB is child- hood maltreatment (Jaffee et al., 2004; Kerig & Becker, 2015), including physical abuse, sexual abuse, and neglect. Youth with maltreatment histories are at elevated risk for adolescent violence, delinquency, and substance use (Oshri et al., 2011), particularly in combination with other family-level stressors such as domestic violence (Moylan et al., 2010). Additionally, early maltreatment has long-term sequelae: among 574 youth followed prospectively, youth with abuse histories were almost twice as likely than non- abused youth to be arrested 17 years later (Lansford et al., 2007). Maltreatment likely has enduring effects on EB by influencing the biological processes involved in responding to the social envi- ronment (Bender, 2010; Egeland, Yates, Appleyard, & Dulmen, 2002; Rogosch, Oshri, & Cicchetti, 2010). Drawing from evolu- tionary theories, exposure to stressful and chaotic early environ- ments may shift organisms toward heightened biological sensitivity to the environment, which may calibrate their bio- logical systems (e.g., activation thresholds, stress reactivity) to bet- ter match their ecological environment (Boyce & Ellis, 2005; Ellis & Boyce, 2008). For example, early exposure to a dangerous/ unpredictable environment (e.g., physical abuse) may heighten vigilance to threat and increase aggressive behaviors to thwart Author for correspondence: Irene Tung, Department of Psychology, UCLA, 1285 Franz Hall, Box 951563, Los Angeles, CA 90095-1563; E-mail: itung@ucla.edu © Cambridge University Press 2018 Cite this article: Tung I, Noroña AN, Lee SS (2019). Childhood maltreatment affects adolescent sensitivity to parenting and close friendships in predicting growth in ex- ternalizing behavior. Development and Psychopathology 31, 1237–1253. https://doi.org/ 10.1017/S0954579418000585 Development and Psychopathology (2019), 31, 1237–1253 doi:10.1017/S0954579418000585