Incest Avoidance as a Function of Environment and Heredity [and Comments and Reply]

Abstract

Although it has repeatedly been demonstrated that behavior is best understood as a function of the interrelatedness of nature and nurture, many social scientists persist in posing these determinants adversatively and then contend that genes and biology are, at best, minor determinants of behavior. Analysis in incest avoidance illustrates the inadequacy of efforts to reduce to irrelevance genetic determinants. Man and many other species exhibit strong tendencies to avoid incest. Conspecifics who are intimately associated during the infancy and childhood of one or both do not find each other sexually attractive if alternative mates are available. Migration shortly after puberty, usually by the male, is characteristics of social primates. Incest vere seldom occurs, and when it does the copulatory act differs markedly from normal mating. Incest within intact human families is rare. Inbreeding with other close relatives is inhibited by human awareness of inbreeding depression, not by any apparent genetic predisposition. Societies which discourage close inbreeding should be more viable than those which encourage it. Their behaviors can only be explained as a result of environment interacting with heredity. Concern is expressed about the damage done to the social sciences by denial of relevance to biological and genetic factors.