One of the major changes in developmental psychology during the past 50 years has been the acceptance of the important role of nature (genetics) as well as nurture (environment). Past research consisting of twin and adoption studies has shown that genetic influence is substantial for most domains of developmental psychology. Present research has moved beyond documenting the importance of genetics to investigate the mechanisms by which genetic influences affect behavioral development. The future of genetic research in developmental psychology lies in DNA: Identifying the specific genes responsible for the widespread influence of genetics and using these genes to investigate developmental pathways between genes and behavior.