Conceptualizing genetic influences on early behavioral development.

Abstract

The overarching goal of human behavioral genetics is to understand genetic influences on behavior while also considering the complementary influence of the environment. This paper highlights the explicit goals of behavioral genetics, including some that are particularly relevant to the study of human development, and some common misunderstandings concerning the field. Examples are given to illustrate specifically the degree of genetic influence in behaviors representing physical, cognitive and emotional development during infancy using the methodology of twin, adoption and parent-offspring designs. The effect sizes in the prediction of complex behaviors are typically modest, and thus there is ample room for multiple predictors from different domains. Moreover, there is a fundamental recognition that distal and proximal causes can be different in kind, and that factors that play a role in the origins of behavioral dispositions are different from those that elicit or maintain actual behavior.