Early findings are reported from the Michigan State University Vulnerability Study, a study of differences in parents and children of families with an alcoholic father and matched, community control families with a non-alcoholic father. Male preschool children in the alcoholic homes were the target group, because they are 6 to 10 times more at risk for adult alcoholism than are the control children. As hypothesized, both parents in the high risk families reported more history of antisocial behavior than did control parents. Differences in family climate revealed that the alcoholic families were less likely to pursue moral and religious activities than the other families. Both parents in the alcoholic families described their transactions in more hostile terms than did controls. Both husbands and wives in alcoholic families agreed that their relationship centered on hostility rather than around control. More generally, the data indicate that a group of 4-year-old children who are disproportionately at risk for alcoholism in adulthood are already exposed early in life to parents who are more antisocial in childhood and adulthood, are more hostile toward each other, and who have created a family environment that is more likely to foster the continuation of such behavior than to moderate it. (Author/RH)