The association between 2D:4D ratio and aggression in children and adolescents: Cross-cultural and gender differences

Two recent meta-analyses have suggested the association between digit ratio (2D:4D) and aggression is weak. This conclusion has been criticised because the meta-analyses conflate forms of aggression that show strong sex differences with those that do not, and most studies have considered post-pubertal participants. We test the influence of 2D:4D and ethnicity in the expression of aggression in children and adolescents in four ethnic groups of European and African origin. Buss and Perry aggression questionnaire. Direct measurement of the 2nd and 4th digits. 1296 children and adolescents from Tanzania and Russia from 4 ethnic groups – Datoga, Meru, Russians, Tatars. There were ethnic and gender differences in ratings on aggression with boys consistently reporting more physical aggression. In all four samples right 2D:4D was significantly lower in boys, compared to girls. With regard to our total sample of boys, the right 2D:4D was significantly and negatively associated with self-ratings on physical aggression, but no association was found for left 2D:4D. No associations between 2D:4D and physical aggression were found for girls. Hostility was negatively correlated with 2D:4D for boys, and anger was positively correlated with 2D:4D in girls. Sex differences were strongest for right 2D:4D (boysgirls). Right 2D:4D was negatively related to physical aggression in boys only, suggesting possible relationship to prenatal androgenization. •Sex differences were strongest for right 2D:4D (boysgirls).•Right 2D:4D was negatively related to physical aggression in boys only.•The association between right 2D:4D and aggression was negative and most strongest in forms of aggression that are sexually dimorphic.