Genetic Influences on Alcoholism Risk: A Review of Adoption and Twin Studies.

Researchers have used two different strategies to determine the relative contributions of genes and shared environment to the development of alcoholism among family members: the adoption study and the twin study. Adoption studies compare the risk to biological relatives with the risk to adoptive relatives of alcoholics. Twin studies compare identical and fraternal pairs of twins reared in the same environment. Evidence indicates an important genetic influence on alcoholism risk; this influence appears as strong in women as in men. These results have been remarkably consistent despite major differences between research methods.