title: Happy orang-utans live longer lives.
abstract: Nonhuman primate ageing resembles its human counterpart. Moreover, ratings of subjective well-being traits in chimpanzees, orang-utans and rhesus macaques are similar to those of humans: they are intercorrelated, heritable, and phenotypically and genetically related to personality. We examined whether, as in humans, orang-utan subjective well-being was related to longer life. The sample included 184 zoo-housed orang-utans followed up for approximately 7 years. Age, sex, species and number of transfers were available for all subjects and 172 subjects were rated on at least one item of a subjective well-being scale. Of the 31 orang-utans that died, 25 died a mean of 3.4 years after being rated. Even in a model that included, and therefore, statistically adjusted for, sex, age, species and transfers, orang-utans rated as being "happier" lived longer. The risk differential between orang-utans that were one standard deviation above and one standard deviation below baseline in subjective well-being was comparable with approximately 11 years in age. This finding suggests that impressions of the subjective well-being of captive great apes are valid indicators of their welfare and longevity.
authors.affiliation: Department of Psychology, School of Philosophy, Psychology and Language Sciences, The University of Edinburgh, Edinburgh, UK. alex.weiss@ed.ac.uk
authors.forename: Alexander
authors.initials: A
authors.lastname: Weiss
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Adams
authors.forename: James E
authors.initials: JE
authors.lastname: King
mesh_terms: D000818:Animals; D005260:Female; D006240:Happiness; D008136:Longevity; D008137:Longitudinal Studies; D008297:Male; D057079:Pongo / Q000502:physiology / Q000523:psychology*; D011446:Prospective Studies