Targeting youth violence: Modifiable environmental factors and gene-environment interactions in Chinese left-behind...

Youth aggressive behavior is a major public health concern, with Chinese left-behind children (LBC) particularly vulnerable due to prolonged parental separation. The underlying mechanisms and contextual factors driving aggression in LBC remain unclear.

Cross-sectional study.

This cross-sectional study was conducted among 2999 students (664 LBC, 2355 non-left-behind children, NLBC) from 6 schools in a city in Northeast China. Aggression, parent-child attachment, classroom environment, and media violence exposure were assessed using validated scales. Buccal samples from 648 participants were collected for genotyping. Multiple regression and two-way ANOVA were performed to examine direct effects and gene-environment interactions on aggression.

Aggression scores were significantly higher in LBC than in NLBC (t = 4.924, p < 0.001). For LBC, aggression was negatively associated with paternal trust (β = -0.157) and classroom order (β = -0.153), while positively associated with paternal alienation (β = 0.117), classroom competition (β = 0.167), and media violence exposure (β = 0.155). For NLBC, aggression was negatively linked to maternal trust (β = -0.098), classroom order (β = -0.100) and peer relationships (β = -0.117), whereas positively linked to maternal alienation (β = 0.130), competition (β = 0.166), and media violence (β = 0.134). The low-activity MAOA (MAOA-L) genotype moderated these associations, heightening sensitivity to both adverse and supportive environments.

Aggression in LBC is influenced by both environmental and genetic factors. These findings highlight the importance of school-based interventions, structured classroom management and targeted psychosocial support, as well as family and community engagement, to mitigate aggression and inform public health strategies for vulnerable youth populations.