The Emanuel Miller Memorial Lecture 1993. Genetic research and identification of environmental influences.

As the importance of genetic influence in developmental psychopathology becomes widely accepted, we should not lose sight of the importance of genetic research for the investigation and identification of environmental influences. First, genetic research provides the best available evidence for the importance of nongenetic factors in behavioural development. Rarely does genetic influence account for more than half of the variance. Second, genetic research indicates that environmental effects on behavioural development largely involve nonshared environmental processes that make children in the same family different from one another. New research on this topic is presented and implications for research are discussed.