On the same day when DNA was collected, each subject completed the Aggression Questionnaire (AQ) [22]. AQ is a 29-item scale divided into four subscales: physical aggression (9 items), verbal aggression (5 items), anger (7 items), and hostility (8 items). Each statement was assessed by a five-point Likert scale (from 1 = never or hardly ever applies to me, to 5 = very often applies to me). Two items were reverse scored. In addition to the scores on each subscale, a total score was also calculated. AQ measures aggressive attitudes that are consistent across an extended time frame and characterological in nature, and is therefore considered a trait measure of aggression [33]. AQ is related to other self-report measures of aggression as well as behavioral indicators of aggression. The AQ subscales have high levels of internal consistency and moderate to high levels of test-retest reliability [34]. In the present study, data analysis was based on the physical aggression (AQ-PA) subscale. Statements rating AQ-PA included: “I have become so mad that I have broken things”, “Once in a while I can't
