Chimpanzees are indifferent to the welfare of unrelated group members

Humans are an unusually prosocial species—we vote, give blood, recycle, give tithes and punish violators of social norms. Experimental evidence indicates that people willingly incur costs to help strangers in anonymous one-shot interactions, and that altruistic behaviour is motivated, at least in part, by empathy and concern for the welfare of others (hereafter referred to […]

Grooming reciprocity in wild male chimpanzees

Understanding cooperation between unrelated individuals remains a central problem in animal behaviour; evolutionary mechanisms are debated, and the importance of reciprocity has been questioned. Biological market theory makes specific predictions about the occurrence of reciprocity in social groups; applied to the social grooming of mammals, it predicts reciprocity in the absence of other benefits for […]

Chimpanzees do not take advantage of very low cost opportunities to deliver food to unrelated group members

We conducted experiments on two populations of chimpanzees, Pan troglodytes, to determine whether they would take advantage of opportunities to provide food rewards to familiar group members at little cost to themselves. In both of the experiments described here, chimpanzees were able to deliver identical rewards to themselves and to other members of their social […]

The influence of kin relationship and reciprocal context on chimpanzees’ other-regarding preferences

We investigated the evolutionary origin of other-regarding preferences, one of the strong underlying motivations for altruism, in the chimpanzee, Pan troglodytes. Although altruism is expected theoretically to be kin biased and frequent in a reciprocal context, few experimental studies to date have specifically tested these hypotheses from the viewpoint of proximate mechanisms. We examined the […]

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 […]

Grooming and coalitions in Japanese macaques (Macaca fuscata): Partner choice and the time frame reciprocation

Evidence of a reciprocal exchange of grooming and agonistic support in primates is mixed. In this study, the authors analyzed a large database of grooming and coalitions in captive female Japanese macaques (Macaca fuscata) to investigate their within-group distribution and temporal relations. Macaques groomed preferentially those individuals that groomed them most and supported preferentially those […]

Size matters: Impact of item size and quantity on array choice by chimpanzees (Pan troglodytes)

The authors previously reported that chimpanzees ( Pan troglodytes ) showed a striking bias to select the larger of 2 candy arrays, despite a reversed reward contingency in which the animals received the smaller, nonselected array as a reward, except when Arabic numerals were used as stimuli. A perceptual or incentive-based interference occurred that was […]

The Anticipated Utility of Zoos for Developing Moral Concern in Children

This study asked why parents value zoo experiences for themselves and their children. It proposes a new theory regarding the psychological value of such experiences for the development of identity. The study used a constructivist grounded theory approach to explore parenting perspectives on the value of zoo visits undertaken by eight families from three adjacent […]

The evolution of morality

Complex animal societies are most successful if members minimise harms caused to one another and if collaboration occurs. In order to promote this, a moral structure inevitably develops. Hence, morality has evolved in humans and in many other species. The attitudes which people have towards other humans and individuals of other species are greatly affected […]

Dominant nestlings displaying female-like melanin coloration behave altruistically in the barn owl

When competing over parental resources, young animals may be typically selfish to the point of siblicide. This suggests that limited parental resources promote the evolution of sibling competition rather than altruistic or cooperative behaviours. In striking contrast, we show here that in 71% of experimental three-chick broods, nestling barn owls, Tyto alba, gave food to […]