Ethological Studies Using Twins: Doing What Comes Naturally

Combining ethological methods with twin and adoption designs enables the testing of novel hypotheses regarding human behavior. Specifically, genetic influences on behaviors expressed in naturalistic and semi-naturalistic social settings can be observed, affording insights and ideas that might otherwise be missed. This article briefly reviews the logic of twin and adoption research methods, then illustrates their application in a series of ethologically-based studies concerning cooperation and competition, social relatedness and tacit coordination (decisionmaking). Future studies that would potentially benefit from this approach are suggested.