ethologyinternational journal of behavioural biology Ethology CURRENT ISSUES – PERSPECTIVES AND REVIEWS Perspectives: Hamilton’s Legacy: Mechanisms of Kin Recognition in Humans Jill M. Mateo Department of Comparative Human Development, Institute for Mind and Biology, The University of Chicago, Chicago, IL, USA (Invited Review) Correspondence Abstract Jill M. Mateo, Department of Comparative Human Development & Institute for Mind and The behavior literature is replete with examples of individuals exhibiting Biology, The University of Chicago, 940 East costly acts that benefit someone else. These examples troubled Darwin so 57th Street, Chicago, IL 60637, USA. much so that he thought they would be fatal to his theory of natural selec- E-mail:
[email protected] tion. A century later, W. D. Hamilton refined that theory by showing, quantitatively, that such acts could be favored if the individuals involved Received: October 18, 2014 were relatives. His theory of inclusive fitness is generally considered one Initial acceptance: November 18, 2014 of the greatest theoretical advances in evolution since Darwin’s time. Less Final acceptance: December 26, 2014 appreciated from Hamilton’s 1964 paper is the hypothesis that mecha- (M. Hauber) nisms favoring accurate kin recognition will also be selected. Here, I doi: 10.1111/eth.12358 review those recognition mechanisms and survey the literature on human kin recognition. Although not often considered, humans both produce Keywords: kin recognition, humans, cues to kinship that vary with genetic relatedness and have perceptual Hamilton, inclusive fitness, discrimination abilities to detect these cues in others and assess that relatedness. The potential functions of these abilities are discussed. Importantly, gaps in our understanding of the development and use of recognition mecha- nisms are noted.