Objective: To explore the effect of genetic and environmental factors on externalizing behaviors of children.
Methods: A total of 168 twin pairs aged 6-16 years were recruited. Their parents completed Achenbach Child Behavior Checklist (CBCL) to evaluate the children's externalizing behaviors. The parents also completed FACESII-CV and GHQ-12 to assess their family environment. Structural equation modeling was performed to evaluate the effects of additive genetic factors (A), common environmental factors (C) and individual-specific environmental factors (E) on the externalizing behaviors.
Results: The effect of A, C, and E on externalizing behaviors were 0.39 (95% CI: 0.22-0.62), 0.51 (95% CI: 0.28-0.67), and 0.10 (95% Cl: 0.07-0.15), respectively. Significant correlations were found between the children's externalizing behaviors and the total GHQ-12 scores of their fathers and mothers (r = 0.24, P < 0.05; r = 0.30, P < 0.05). The externalizing behaviors were also correlated with family adaptability (r = 0.27, P< 0.01). The logistic regression identified mother's habits, such as smoking and drinking as risk factors of their children's externalizing behaviors.
Conclusion: Externalizing behaviors are mainly affected by shared environmental factors. Externalizing behaviors are related to general mental health of fathers and mothers and the family adaptability.