Determinants of cognitive performance and social preferences across age in Barbary macaques (Macaca sylvanus)

Abstract

Aging is a universal process that occurs in almost all organisms and is defined as a progressive decrease in physiological functioning. For centuries, researchers have been interested in aging processes and their consequences. This is partly due to the fact that the proportion of older adults in human societies worldwide has increased in recent decades.In addition to research on the physiological basis of aging, it becomes increasingly important to study social aging. With increasing age, the size of the social network often decreases, which can have an impact on health and mortality risk. Psychological theories have been developed that attempt to disentangle the factors that explain the declining sociality in old age. To better understand age-related changes during lifespan from an evolutionary perspective, comparative studies are essential. Due to a similar physiological and cognitive aging process in the absence of societal norms that shape social aging in human societies, non-human primates can provide valuable insights here.The aim of this dissertation was to establish a link between the psychology of aging and behavioural biology. For that purpose, I studied Barbary macaques (Macaca sylvanus) as a model species to determine whether comparable patterns also occur in non-human primates. Studying non-human primates allowed to explicitly test hypotheses derived from psychological theories and at the same time provides insights for new theory building. The