Among EA participants, adolescent EXT PGS predicted the adolescent’s externalizing behavior (β = .23, [95% CI .15, .31]) and accounted for 5% of the variance after we controlled adolescent sex and age. In the combined model, parental EXT PGS added incremental R2 to adolescent EXT PGS in predicting adolescent externalizing behavior, raising total variance accounted for in outcome to 6%. Parental EXT PGS was associated with adolescent externalizing behavior (β = .09, [95% CI .01, .17], over and above adolescent’s own EXT PGS (β = .18, [95% CI .09, .26]. These results indicate that parental EXT PGS uniquely predicted their children’s externalizing behavior beyond the variance associated with adolescents’ own EXT PGS, providing evidence for genetic nurture.
