The first chapter in the last section of this volume, Phenotypic Studies, is a brief summation of the biochemical phenotypic markers in genetic alcoholism, presented by Ivan Diamond and Adrienne Gordon. In chapter 10, Henri Begleiter and Bernice Porjesz review the major neurophysiological phenotypic factors. This chapter is a good introduction to the field. They describe the confounding features of alcoholism, which make it difficult to identify specific genes, and the specific criteria critical for identifying a genetically influenced marker. They then discuss the pertinent findings from selected EEG and event-related brain potential studies. In chapter 12, Ralph Tarter et al. describe the studies in behavioral genetics that look to elucidate the etiology of alcoholism. Tarter presents the results from his well-known work, along with other studies looking at temperament associated with a greater risk for alcoholism. As a child psychiatrist who works with children of substance-abusing parents, I found this chapter very compelling. Gerald McClearn and Robert Plomin, in chapter 13, discuss various research strategies for the search for genetic influences on the phenotypes described in previous chapters. They stress the need for quantitative genetic research in this field. In the final chapter, Alexander Wilson and Robert Elston explain linkage analysis and review the linkage analysis research of alcoholism.