Apes reciprocate food positively and negatively

Reciprocal food exchange is widespread in human societies but not among great apes, who may view food mainly as a target for competition. Understanding the similarities and differences between great apes' and humans’ willingness to exchange food is important for our models regarding the origins of uniquely human forms of cooperation. Here, we demonstrate in-kind food exchanges in experimental settings with great apes for the first time. The initial sample consisted of 13 chimpanzees and 5 bonobos in the control phases, and the test phases included 10 chimpanzees and 2 bonobos, compared with a sample of 48 human children aged 4 years. First, we replicated prior findings showing no spontaneous food exchanges in great apes. Second, we discovered that when apes believe that conspecifics have ‘intentionally’ transferred food to them, positive reciprocal food exchanges (food-for-food) are not only

Bis-Bas-Book

When facing situations that involve risk and reward, some may focus on the opportunity for reward, whereas others may focus on potential risks. Here, we used an original set of pictorial scenarios to try and predict 3- to 8-year-olds’ reward-seeking and risk-avoiding behavior in three decision-making scenarios (N=99; Mage=5.6; 47% girls). We found that children’s reward-risk tendencies did not predict sharing behavior in a dictator-game ‘sharing’ task. However, they predicted children’s monopolizing behavior in a dictator-game ‘taking’ task and their preferences between taking home a ‘risky’ or a ‘safe’ reward in a choice-preference task. Overall, using a set of original pictorial scenarios to assess individual differences early on in development is offered as a proof-of-concept that bridges individual differences and decision-making domains and exposes behavioral patterns that were thus far hidden

Waste aversion reduces inequity aversion among Chinese children

An underlying aspect of the development of fairness is an aversion from unequal outcomes between equally deserving parties, which is robust by middle-childhood, but evident primarily in western cultures. Here, 7-years-old Chinese&rsquo;s willingness to accept inequity, when it clashes with two culture-specific values of &ldquo;Thrift&rdquo; and &ldquo;Interdependence&rdquo;, was examined. In studies 1 &amp; 2 (N=60; 3rd-party context), children were more willing to accept inequity only when the alternative requires them to waste resources or to ignore social-relationships. In Study 3 (N=84; 1st-person), waste-aversion was found to be even stronger than disadvantageous and advantageous inequity aversions. These findings broaden the conceptual accounts regarding the development of children&rsquo;s inequity aversion across-cultures, emphasizing the impact of culture-specific object-related (i.e., waste) and social-related considerations.</p