Alcoholism has repeatedly been implicated in many significant social and health problems, yet little is known concerning etiology before age 12. As part of a longitudinal project to investigate alcoholism etiology in preschool children, a study was undertaken which compared families with male preschool children who are statistically at high risk for becoming alcoholic adults (N=9) to a sample of same-aged community control peers (N=9). (Male preschool children are "high risk" if they are the offspring of untreated, alcoholic fathers.) Home interviews and standardized tests were utilized to assess each child's developmental functioning including: activity level; mood; aggression; attention span; concept formation, using Piagetian-like tasks to determine knowledge of alcoholic beverages; and parent-child interaction. Parents completed the self-administered Short Michigan Alcoholism Screening Test (SMAST) and a drinking and drug history. An analysis of the results showed that control boys performed significantly better on indices of language, personal/social, fine motor, and adaptive development than did their at-risk peers. On tasks designed to assess knowledge of alcoholic beverages, the high risk boys had earlier and more sophisticated cognitive structures related to the concept of alcohol than did the control boys. No significant differences were found on parent report measures of temperament or child behavioral symptomatology. The data suggest that education programs about alcohol and its uses could appropriately begin with kindergarten, matching the child's emerging cognitive abilities. (BL)