BIAS IN THE DESIGN OF STUDIES WHICH EXAMINE GENETIC AND ENVIRONMENTAL-INFLUENCES ON BEHAVIOR

Genetic and environmental factors may interact to influence the develo pment of complex disorders such as schizophrenia, depression and alcoh olism. Twin and adoption studies are used to examine the relative infl uence of these factors on such behaviours. We propose a set of guideli nes for critiquing these studies. Results of the methodologically soun d studies may be useful in identifying high risk populations and desig ning and implementing prevention and treatment programs.