The EEGs of young (21-25-year-old) sons of alcoholics and their matched controls (n = 24 pairs) were computer evaluated to assess activity in the 12-20 Hz (beta) range. Subjects were blindly exposed to ethanol and placebo drinks while EEG was gathered at baseline and 90 min postconsumption. Men with alcoholic fathers [family history positive (FHP)] displayed significantly more beta activity at 90 min postethanol consumption than the men who had no alcoholic relatives [family history negative (FHN)]. In addition, when subjects were sorted into "low" and "moderate" drinkers depending on their drinking practices, additional differences were found between groups. Within the FHN subjects, moderate drinkers were found to have significantly more energy in the beta frequencies at both baseline and at 90 min postdrug than low drinkers. However, though family history positive subjects had overall increases in 12-20 Hz activity compared with the FHN subjects, no significant differences were found between moderate and low drinkers within the FHP population. Taken together, these studies suggest that drinking practices and a familial history for alcoholism can modify the beta content of the EEG in the 12-20 Hz range in young men.