黑猩猩與人類有不少共同點：它們會使用矛打獵,、玩簡單的玩具，也會為死去的同伴“默哀”,。美國最新研究又找到一個新共同點：無私,。
研究報告8月8日由美國《國家科學院院刊》月刊發(fā)表。
盡量讓“鄰居”獲益
美國埃默里大學研究人員找來七只雌性黑猩猩,，每次實驗時隨機挑選兩只,。他們把兩只黑猩猩分別放在兩個相鄰的籠子里，讓它們可以互相看見,。接著,，研究人員讓其中一只黑猩猩從兩枚顏色不同的硬幣中挑選一枚。
一種顏色的硬幣代表“分享”,，如果黑猩猩選中,，研究人員就會分別給兩只黑猩猩香蕉；另一種顏色的硬幣代表“自私”,，如果選中,，那么只有選硬幣的黑猩猩獲得香蕉，另一只沒有,。
香蕉用紙包住,，這樣，一旦不挑選硬幣的黑猩猩也獲得香蕉,，它剝開紙時,，聲響就會提醒挑選硬幣的黑猩猩，“鄰居”因為它的行動獲益,。
研究人員發(fā)現,，幾乎所有黑猩猩掌握選硬幣的“奧妙”后，都會選擇能讓“鄰居”獲益的那枚硬幣,。
有無壓力都會分享
美國趣味科學網站8日引述埃默里大學研究員,、比較心理學家霍納的話報道：“對我來說最重要的發(fā)現是，黑猩猩與人一樣會考慮到‘他人’的需要和愿望,。”
研究人員還發(fā)現一個有趣的現象：黑猩猩對有耐心或有“禮貌”的“鄰居”表現出特別的友好,，愿意幫它們獲得香蕉。但對制造噪音,、不停請求或向自己吐口水的“鄰居”則沒那么“大方”,。
“這之所以有意思，是因先前一直認為只會在壓力下黑猩猩才分享食物,，”霍納說,，“我們的實驗得到完全相反的結論：黑猩猩沒有壓力或壓力小時會分享食物，直接的壓力或威脅會減少分享，這可能是負面情緒作祟,。”（生物谷Bioon.com）
DOI:10.1073/pnas.1111497108
PMC:
PMID:
Spontaneous prosocial choice by chimpanzees
Horner, Victoria; Carter, J. Devyn; Suchak, Malini; de Waal, Frans B. M.
The study of human and primate altruism faces an evolutionary anomaly: There is ample evidence for altruistic preferencesin our own species and growing evidence in monkeys, but one of our closest relatives, the chimpanzee (Pan troglodytes), is viewed as a reluctant altruist, acting only in response to pressure and solicitation. Although chimpanzee prosocialbehavior has been reported both in observational captive studies and in the wild, thus far Prosocial Choice Tests have failedto produce evidence. However, methodologies of previous Prosocial Choice Tests may have handicapped the apes unintentionally.Here we present findings of a paradigm in which chimpanzees chose between two differently colored tokens: one “selfish” tokenresulting in a reward for the actor only (1/0), and the other “prosocial” token rewarding both the actor and a partner (1/1).Seven female chimpanzees, each tested with three different partners, showed a significant bias for the prosocial option. Prosocialchoices occurred both in response to solicitation by the partner and spontaneously without solicitation. However, directedrequests and pressure by the partner reduced the actor's prosocial tendency. These results draw into question previous conclusionsindicating that chimpanzees have a limited sensitivity to the needs of others and behave prosocially only in response to significantprompting.
