The effects of progressive intoxication were studied in male social drinkers classified from prior histories as either aggressively (A) or nonaggressively (NA) predisposed while intoxicated. Two groups of two A and two NA subjects engaged in videotaped group discussions that were analyzed by Bales interaction process analysis (IPA). At comparable levels of ad libitum alcohol intake in a natural drinking environment, significantly more verbal activity was displayed by the A subjects than by the NA subjects (P <.001), including IPA category D (P <.025). The A subjects tended to address the group as a whole rather than individual members (P <.001) and NA subjects rather than other A subjects (P <.01). Free testosterone levels assessed from saliva were higher among A subjects than among NA subjects (P <.05) with no significant changes related to time and progressive intoxication. The results suggest that the tendency to behave aggressively while intoxicated may be a fairly stable individual trait, possibly related to androgen levels and active or coercive modes of social communication.