Image Scoring in Great Apes
‘Image scoring’ occurs when person A monitors the giving behaviour of person B towards person C.We tested for ‘image scoring’ in chimpanzees, bonobos, gorillas, and orangutans. Subjects passively observed two types of incident: (i) a ‘nice’ person gave grapes to a human beggar, and (ii) a ‘nasty’ person refused to give. The subject witnessed both […]
Responses of chimpanzees to cues of conspecific observation
Recent evidence has shown that humans are remarkably sensitive to artificial cues of conspecific observation when making decisions with potential social consequences. Whether similar effects are found in other great apes has not yet been investigated. We carried out two experiments in which individual chimpanzees, Pan troglodytes, took items of food from an array in […]
Male monkeys fight in between-group conflicts as protective parents and reluctant recruits
In many social species, group members cooperate to defend a communal home range. Fighting in between-group conflicts carries an opportunity cost, a risk of injury or death, and the possibility of exploitation by free-riding group members. As a result, it is rare that all group members fight in a given between-group conflict, and individual participation […]