by physical aggression scores of the Aggression Questionnaire (Wilk's λ = 0.99; F2,170 = 0.74, P = 0.47; AQ-PA, see Materials and Methods [22]) and thus, for the purposes of our analysis, we grouped heterozygous female participants together with low-low homozygous females following the convention of a previous study [23]. The low and high enzyme activity groups accounted respectively for 43% and 57% of the total male participants (N = 82) and 54% and 46% of the total female participants (N = 153). Genotype frequencies within the sample did not significantly deviate from those reported for other Caucasian populations (χ2 = 2.51, df = 4, P = 0.64) [12], [14].
