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Understanding the Etiology of Complex Traits: Symbiotic Relationships Between Psychology and Genetics


Elena L. Grigorenko, Child Study Center, Yale University, 230 South Frontage Road, New Haven, CT 06510; e-mail:


ABSTRACT— The present article offers comments on the infusion of methodologies, approaches, reasoning strategies, and findings from the fields of genetics and genomics into studies of complex human behaviors (hereafter, complex phenotypes). Specifically, I discuss issues of generality and specificity, causality, and replicability as they pertain to molecular genetic studies of human phenotypes. These issues are illustrated with findings from genetic linkage and association studies investigating the etiology of disorders of spoken and written language—an area of inquiry that has been consistently referenced as one of the most successful in terms of its progress in understanding the genetic bases of human behaviors. I complete this discussion with comments on how the stronger presence of genetics and genomics in psychology is changing the conceptualization and investigation of research questions and affecting the next generation of interdisciplinary research.