Gene-Environment Interplay in the Relationship Between Gaming Addiction and Close Friends’ Gaming

Both peer influences and genetics have been linked to gaming addiction (GA) in adolescents and young adults. This study examined the gene-environment interplay (gene-environment correlation [rGE] and gene-environment interaction [G x E]) between close friends' gaming (CFG) and GA among South Korean twins. A total of 1462 twins aged 15-29 years (mean = 22.63 ± 2.8 years) completed an online survey that included a 20-item GA measure and a single item assessing CFG. Bivariate Cholesky model-fitting analysis was conducted to examine evidence for rGE in the relationship between GA and CFG. Bivariate G x E model-fitting analysis was performed to determine evidence for G x E effects. A significant genetic correlation (<i>r</i>_g = .37; 95% CI [0.24, 0.49]) between GA and CFG supported the role of gene-environment correlation, suggesting that individuals with a genetic predisposition for GA may selectively associate with peers who frequently engage in gaming. The model testing G x E effects indicated that environment-environment interaction was present in the relationship between CFG and GA, such that CFG increased nonshared environmental effects on GA. This pattern provided evidence for peer socialization effects, wherein peers influence the development of GA independently of genetic risk.