In general, as humans, healthy aging impacts our cognitive and affective functions. Our cognitive capacity declines while our emotional lives become more positive and social relationships take a more central role.

The reasons for this are unknown, though scientists suspect it may be because humans have awareness of a limited lifetime. This could possibly lead to a greater interest in maintaining social relationships at the expense of the non-social world in the face of waning cognitive and physical resources.

However, a recent study conducted by researchers at California National Primate Research Center (CNPRC) found humans may be unique in this regard.

The scientists tested whether old rhesus macaques lost interest in non-social stimuli, collecting data from males and females between 4 and 30 years old. Each macaque was tested with a food puzzle outfitted with an activity monitor to evaluate their inclination to manipulate the puzzle in order to gain a food reward. The team found no indication older macaques were less interested in the puzzle than younger ones, nor were they less able to solve it.

These findings suggest there are no significant age-related changes in environmental exploration — at least in rhesus macaques — and indicate there is more research to be conducted to understand such social phenomena across species.