A theory of human life history evolution: Diet, intelligence, and longevity


  • Hillard Kaplan,

    Search for more papers by this author
    • Hillard Kaplan is Professor at the University of New Mexico. His recent research and publications have focused on integration of life history theory in biology and human capital theory in economics, with specific emphases on fertility, parental investment, and aging in developed, developing, and traditional settings. He has also conducted fieldwork with native South Americans and southern Africans.

  • Kim Hill,

    Search for more papers by this author
    • Kim Hill is an Associate Professor at the University of New Mexico. He studies human behavioral ecology with a focus on life history theory, foraging patterns, sexual division of labor, food sharing, and the evolution of cooperation. He has carried out fieldwork in five different South American hunter-gatherer or tribal horticulturalist populations in the past 23 years.

  • Jane Lancaster,

    Search for more papers by this author
    • Jane Lancaster is Professor of Anthropology at the University of New Mexico. Her research and publications are on human reproductive biology and behavior especially human parental investment; on women's reproductive biology of pregnancy, lactation and child-spacing; and on male fertility and investment in children. She edits the quarterly journal, Human Nature, which publishes research in human evolutionary ecology.

  • A. Magdalena Hurtado

    Search for more papers by this author
    • A. Magdalena Hurtado is Associate Professor in the Department of Anthropology, University of New Mexico. She has done research on a wide range of problems in human behavioral ecology and evolutionary medicine among the Ache, Hiwi, and Machiguenga of Lowland South America. She is Co-Director of the Native Peoples and Tropical Conservation Fund, University of New Mexico.


Human life histories, as compared to those of other primates and mammals, have at least four distinctive characteristics: an exceptionally long lifespan, an extended period of juvenile dependence, support of reproduction by older post-reproductive individuals, and male support of reproduction through the provisioning of females and their offspring. Another distinctive feature of our species is a large brain, with its associated psychological attributes: increased capacities for learning, cognition, and insight. In this paper, we propose a theory that unites and organizes these observations and generates many theoretical and empirical predictions. We present some tests of those predictions and outline new predictions that can be tested in future research by comparative biologists, archeologists, paleontologists, biological anthropologists, demographers, geneticists, and cultural anthropologists.