Are extroverted chimpanzees happier?

Robinson, L. M., Altschul, D. M., Wallace, E. K., Úbeda, Y., Llorente, M., Machanda, Z., & Weiss, A. (2017). Chimpanzees with positive welfare are happier, extraverted, and emotionally stable. Applied Animal Behaviour Science.

This study explored associations between chimpanzee personality, subjective well-being, and welfare, and whether care giver ratings are a reliable way to assess chimpanzee welfare.

Staff expertise and familiarity with animals including chimpanzees can be used to monitor the welfare of individual animals housed in captivity. People often misinterpret the behaviour and emotional states of chimpanzees for example a fear grimace can be mistaken as a smile. It is therefore not yet understood how reliable such welfare assessments are. Research has found that some animal caregivers record chimpanzee personality and well-being reliably, but the consistency of this is unclear. It has been suggested that studying welfare ratings in combination with traits such as personality can give insight into why some individuals cope better in captivity than others. 

Introversion is linked to poor welfare

The study took place at Edinburgh and Fundació Mona zoo, both of which house chimpanzees. Researchers and keepers at each zoo were asked to complete questionnaires. Participants were asked to rate the chimpanzees in relation stress, psychological stimulation, and behavioural indicators of negative and positive welfare states. The chimpanzee’s personalities were also rated.

The study found that both researchers and keepers agreed on welfare ratings. Higher welfare ratings were associated with more extroverted individuals with lower neuroticism. Similar findings have been found in humans and other primate species. This indicates that emotional stability and sociability are extremely important for happiness in primates. These findings suggest these questionnaires could be a useful and inexpensive tool for monitoring chimpanzee welfare. The questionnaires could especially be useful during times of change, for example, when a new group member is introduced. They could also be used by keepers to ensure that chimpanzees which may be more prone to experiencing negative emotional states and poor welfare are monitored carefully.

World Animal Protection’s view

We believe this study provides an insight into the links between animal personality and welfare. This area of research is important to help us consider the welfare of individuals. The research also indicates that with appropriate training and knowledge zoo staff can accurately assess the welfare of chimpanzees under their care.