Evidence for a midlife crisis weiss et al 2012

Evidence for a midlife crisis in great apes consistent with the U-shape in human well-being
Alexander Weissa,b,1, James E. Kingc, Miho Inoue-Murayamad, Tetsuro Matsuzawae, and Andrew J. Oswaldf,g a Scottish Primate Research Group, bDepartment of Psychology, School of Philosophy, Psychology and Language Sciences, University of Edinburgh, Edinburgh EH8 9JZ, United Kingdom; cDepartment of Psychology, University of Arizona, Tucson, AZ 85721; dWildlife Research Center of Kyoto University, Sakyo, Kyoto 606-8203, Japan; eSection of Language and Intelligence, Primate Research Institute, Kyoto University, Inuyama, Aichi 484-8506, Japan; fDepartment of Economics and Centre for Competitive Advantage in the Global Economy, University of Warwick, Coventry CV4 7AL, United Kingdom; and gInstitute for the Study of Labor, 53072 Bonn, Germany

Edited by George A. Akerlof, University of California, Berkeley, and approved October 11, 2012 (received for review July 22, 2012)

Recently, economists and behavioral scientists have studied the pattern of human well-being over the lifespan. In dozens of countries, and for a large range of well-being measures, including happiness and mental health, well-being is high in youth, falls to a nadir in midlife, and rises again in old age. The reasons for this U-shape are still unclear. Present theories emphasize sociological and economic forces. In this study we show that a similar U-shape exists in 508 great apes (two samples of chimpanzees and one sample of orangutans) whose well-being was assessed by raters familiar with the individual apes. This U-shaped pattern or “midlife crisis” emerges with or without use of parametric methods. Our results imply that human wellbeing’s curved shape is not uniquely human and that, although it may be partly explained by aspects of human life and society, its origins may lie partly in the biology we share with great apes. These findings have implications across scientific and social-scientific disciplines,