The Gene Chase in Behavioral Science

Abstract
The study of genetic influence on behavior has featured two general approaches. The first is to search for a single gene with influence sufficiently great as to be detectable against almost any genetic or environmental background. The second general approach is to apply the statistical models of quantitative genetics that partition variance of a continuously distributed phenotype into various fractions, attributable to the actions of many genes of individually small effect, and to the influence of environment. Recent developments in molecular genetics have provided tools for exploring a middle ground of genetic influence: genes whose effects are not overwhelming, but which account for appreciable proportions of the variance. These quantitative trait loci (QTL) offer attractive prospects of bridging the gap between molecular and quantitative genetic perspectives.