The studies discussed above have used males as subjects almost exclusively. Results of studies in females have been inconsistent. A recent nationwide study with very large sample sizes found lower P3 amplitudes in female alcoholics and their first-degree relatives,6 although not to the same extent as in males (Porjesz et al. 1993). In both men and women, shorter P3 latencies in nonalcoholic siblings suggest a protective effect against the development of alcoholism (Hill and Steinhauer 1993a, b).
