Epidemiological research has clearly demonstrated the importance of a family history as a determinant of future alcohol and, possibly, drug use in offspring of alcoholics. Laboratory studies have examined a wide range of potential markers both in the presence and absence of alcohol challenge, which may predict those subjects at high risk for the future development of alcoholism. While this body of research has yielded several replicable differences in FHP and FHN subjects, it also has been marked by many discrepancies in outcomes across studies. Future refinements in subject ascertainment and laboratory methodologies may help to bring greater procedural uniformity and consistency in study outcomes.