Bonobos voluntarily hand food to others but not toys or tools

Abstract

A key feature of human prosociality is , the most active form of sharing in which donors voluntarily hand over resources Direct transfers buffer hunter-gatherers against foraging shortfalls. The emergence and elaboration of this behaviour thus likely played a key role in human evolution by promoting cooperative interdependence and ensuring that humans' growing energetic needs (e.g. for increasing brain size) were more reliably met. According to the , among great apes only humans exhibit sufficiently strong prosocial motivations to directly transfer food. The suggests instead that while other apes may make transfers in constrained settings, only humans share flexibly across food and non-food contexts. In controlled experiments, chimpanzees typically transfer objects but not food, supporting both hypotheses. In this paper, we show in two experiments that bonobos directly transfer food but not non-food items. These findings show that, in some contexts, bonobos exhibit a human-like motivation for direct food transfer. However, humans share across a far wider range of contexts, lending support to the versatile prosociality hypothesis. Our species' unusual prosocial flexibility is likely built on a prosocial foundation we share through common descent with the other apes.

Teaching varies with task complexity in wild chimpanzees

“…Unlike chimpanzees, bonobos do not use tools for extractive foraging in the wild, and tool sharing may not support cultural transmission of tool use in bonobos. It is also possible that bonobos may value toys or tools differently than do chimpanzees (59).…”

Theory of mind in animals: Current and future directions

“…By , Call and Tomasello concluded that things had changed: several tasks provided converging evidence that apes were sensitive to the goals and intentions that underlie others' actions. For example, they were more patient with an individual who intended to feed them but was unable to do so than with one who was unwilling to share food, they discriminated and responded appropriately to intentional versus accidental actions, they helped others achieve their goals, and they completed others' failed actions (Buttelmann, Carpenter, Call, & Tomasello, ; Buttelmann, Schütte, Carpenter, Call, & Tomasello, ; Call, Hare, Carpenter, & Tomasello, ; Call & Tomasello, ; Krupenye, Tan, & Hare, ; Myowa‐Yamakoshi & Matsuzawa, ; Tomasello & Carpenter, ; Warneken, Hare, Melis, Hanus, & Tomasello, ; Warneken & Tomasello, ; Yamamoto, Humle, & Tanaka, ). There was also a variety of evidence suggesting that apes were aware of what others could see, and perhaps hear, and what others knew on the basis of seeing.…”

Targeted helping and cooperation in zoo-living chimpanzees and bonobos

“…Only by retrieving and consuming their own food and transferring a tool to their partner could both benefit. This is the most salient difference to the study by Krupenye et al [67] and future studies could make an effort to combine the two designs in order to clarify possible explanations.…”