A simulation study indicated that this theory is plausible ( Wolf et al., 2007), and a meta-analysis on studies of boldness, exploration, and aggression in insects, fish, birds, and mammals offered mixed empirical support ( Smith and Blumstein, 2008). These strategies are supported by behavioral adaptations ( Stearns, 1976).ĭifferences in life history strategy have been advanced as one possible explanation for why individuals within populations exhibit stable differences in behavioral, affective, and cognitive dispositions, that is, personality traits ( Dingemanse and Réale, 2005 Réale et al., 2010). Both ends of this continuum are viable fitness strategies, as are, depending upon ecological and social contingences, life history strategies between these extremes. Individuals within these populations are characterized by later and less frequent reproduction, but delayed senescence, and a longer lifespan. At the other end of this continuum are ‘ K-selected’ populations. Individuals within these populations are characterized by early and frequent reproduction, the rapid onset of senescence, and a shorter lifespan. At one end of this continuum are ‘ r-selected’ populations. Life-history theory posits that strategies for increasing individual fitness lay on a continuum that describes an energetic trade-off between maximizing reproductive efforts and maintaining physical health as the organism ages ( Stearns, 1976). For a fuller understanding of how ape personality evolved, future work should explore longevity and fitness in wild chimpanzees, as well as in our other closest relatives, bonobos. They also provide insights into how important personality and life history are to the health and survival of captive animals.

suggest that human and ape agreeableness evolved through individuals who were able to achieve higher fitness by living longer. These two traits may therefore drive uniquely human behaviours that affect health. However, evidence suggests that conscientiousness and neuroticism can influence lifespan in humans. No other personality traits appear to be linked to lifespan in chimpanzees. Like humans, chimpanzees become less open to experiences as they become older. Female chimpanzees who were more open to new experiences also appeared to live for longer, but this apparent association may be influenced by age. Male chimpanzees with higher levels of agreeableness – the personality trait characterized by low aggression and positive social interactions such as cooperation – generally lived for longer. found that different personality traits were associated with longer life in males and females. Since then, 187 of the chimpanzees have died.Īltschul et al. The personalities of the chimpanzees started being rated between seven and 24 years ago. used data from a long-term study of 538 captive chimpanzees to investigate possible associations between longevity and personality traits. However, few studies have been large enough to test all major personality traits in both sexes of an animal species.Īltschul et al.

Previous work in humans and other animals suggested that some personality traits are associated with a longer life. Longevity is an important factor in promoting fitness an animal that lives for longer will have more opportunities to reproduce. How did these distinct personality traits evolve and persist across different species? Ultimately, each trait must provide some fitness benefits that help the animal to reproduce and pass on the trait to its offspring. Our close evolutionary cousins chimpanzees even display the same five major personality traits that we do – extraversion, neuroticism, conscientiousness, openness, and agreeableness – as well as a distinct trait, for dominance.

Like humans, animals have distinct personalities. Our results link the literature on human and nonhuman primate survival and suggest that, for males, evolution has favored the protective effects of low aggression and high quality social bonds. We found that higher agreeableness was related to longevity in males, with weaker evidence suggesting that higher openness is related to longer life in females. Using data from 538 captive chimpanzees ( Pan troglodytes) we tested whether any of the dimensions of chimpanzee personality – agreeableness, conscientiousness, dominance, extraversion, neuroticism, and openness – were associated with longevity, an attribute of slow life history strategies that is especially important in primates given their relatively long lives. Strategies across this spectrum are viable and different suites of personality traits evolved to support these strategies.

Life history strategies for optimizing individual fitness fall on a spectrum between maximizing reproductive efforts and maintaining physical health over time.

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