We first tested for potential gene–environment correlation between 5-HTTLPR and positive parenting. In none of the three studies did correlation analyses reveal significant rGE (study 1 (Alabama Parenting Questionnaire): r=–0.06, P=0.30; study 2 (observed parenting): r=0.01, P=0.75; study 3 (EMBU-C): r=–0.04, P=0.45). Reported parenting was more positive for girls than for boys (study 1: t (306)=2.29, P=0.02; study 3: t (1368)=4.10, P<0.001), but there were no sex differences in observed parenting (study 2: t (196)=1.52, P=0.13). Sex differences in positive affect varied across the three studies as well. No sex difference in the positive affect (t (306)=1.18, P=0.24) was found in study 1; in study 2, girls reported higher levels of positive affect than the boys (t (196)=2.14, P=0.03); and in study 3, girls reported less positive affect (t (1368)=−4.62, P<.001). Age did not have an effect on parenting and positive affect in any of the three studies. Ethnicity was not associated with parenting and positive affect in Studies 1 and 2, but showed a significant association with positive affect in study 3 (F (1 1368)=10.96, P<0.001). Given sex and
