Chimpanzee helping in collaborative and noncollaborative contexts

Chimpanzees, Pan troglodytes, help others in a variety of contexts. Some researchers have claimed that this only occurs when food is not involved and the recipient actively solicits help. In the current study, however, we found that chimpanzees often helped conspecifics obtain food in a pulling task with no solicitation whatsoever, in a situation in […]

Do Chimpanzees (Pan troglodytes) Spontaneously Take Turns in a Reciprocal Cooperation Task?

Reciprocity is considered to be an explanation for altruism toward nonkin. Although there have been many theoretical studies and reciprocity is arguably prevalent in humans, little experimental work has investigated the proximate mechanism of reciprocity in nonhuman animals. The authors tested whether pairs of chimpanzees (Pan troglodytes) would achieve reciprocal cooperation, that is, whether chimpanzees […]

The influence of siblings on begging behaviour

Elaborate solicitation displays are a common feature of interactions between care-givers and offspring. These displays are interpreted as the phenotypic expression of the conflict of interests between parents and offspring over parental investment. Offspring typically have siblings and thus do not exist in isolation. Therefore, they may adjust their begging in response to their siblings’ […]