A twin study on externalizing problem behavior in adolescents in Chongqing City

OBJECTIVE: To explore the relations of adolescents externalizing problem behavior to genetic and environmental factors through twin study. METHODS: The externalizing problem behavior of 66 twin pairs from Chongqing City( aged from 12 to 18years) were investigated with the Youth Self-Report( YSR). The Parenting Styles and Dimensions Questionnaire( PSDQ) and Family Stresses Questionnaire( FSQ), Family Adaptability and Cohesion Scale( FACES) and Stressful Life Event( SLE) were applied to assess their environment factors. The blood sample was collected to identify zygosity oftwins. Structural equation modeling( SEM) was performed to evaluate the relations of adolescents externalizing problem behavior to the additive genetic factors( A), shared environment factors( C) and individual specific environmental factors( E). RESULTS: The effects of A and E on adolescent externalizing problem behavior were 0. 57( 95% CI 0. 37-0. 72) and 0. 43( 95% CI 0. 28-0. 63), respectively. There were significantly negative correlation between externalizing problem behavior and family cohesion( r =-0. 221, P <0. 05), the scores of adolescent externalizing problem behavior were positively correlated with the scores of family stresses( r = 0. 226, P < 0. 05), the scores of stress life events( r = 0. 194, P < 0. 05), the scores of Authoritarian-parenting-style( r = 0. 235, P <0. 05), the scores of Permissive-parenting-style( r = 0. 212, P < 0. 05). The scores of adolescents externalizing behavioral problems were not significantly correlated with the parenting education level and occupation. CONCLUSION: Adolescents externalizing problem behavior are influenced by additive genetic factors and individual specific environmental factors. Additive genetic factors play an important role. Family environment and parental rearing-pattern also have correlation with externalizing behavioral problems.