The P3(00) event-related brain potential (ERP) is used to study the development of alcoholism by comparing males who have a positive family history of alcoholism with control Ss who have no such familial history. Meta-analysis indicated that overall, smaller P3 amplitudes were obtained from males with family histories of alcoholism compared to controls. Moderator analysis indicated that paradigms using difficult visual tasks yielded the most reliable effects. Furthermore, no differences in outcomes were obtained among studies that recruited positive family history Ss exclusively from among individuals whose father had received treatment for alcoholism as compared with other studies. These findings are discussed in the context of using ERPs as an evaluative tool in the study of psychopathology.