The Genetic and Cultural Transmission of Alcohol Use, Alcoholism, Cigarette Smoking and Coffee Drinking: A Review and an Example using a Log Linear Cultural Transmission Model

Summary The simplifying assumptions made by geneticists in the study of behaviour have been reviewed and their relation to the genetics of substance use and abuse have been specified. The most notable problems are the validity of genetic estimates for substance use based on twin data when within twin pair competition or mutual effects have been shown to be present and the fact that broad secular changes in alcohol consumption render heritability values valid only for certain populations at specific points in time. Behaviour genetic methods can however provide information about different sources of environmental variation and tend to show that the family is of little importance, especially for personality traits as well for some aspects of substance use. A simple model to investigate familial and cultural transmission is suggested for traits such as substance use that do not appear, on a priori grounds, to have a strong genetic predisposition.