黑猩猩與人類有不少共同點(diǎn):它們會(huì)使用矛打獵,、玩簡(jiǎn)單的玩具,,也會(huì)為死去的同伴“默哀”。美國(guó)最新研究又找到一個(gè)新共同點(diǎn):無私,。
研究報(bào)告8月8日由美國(guó)《國(guó)家科學(xué)院院刊》月刊發(fā)表,。
盡量讓“鄰居”獲益
美國(guó)埃默里大學(xué)研究人員找來七只雌性黑猩猩,每次實(shí)驗(yàn)時(shí)隨機(jī)挑選兩只,。他們把兩只黑猩猩分別放在兩個(gè)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(huì)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(shí),,聲響就會(huì)提醒挑選硬幣的黑猩猩,,“鄰居”因?yàn)樗男袆?dòng)獲益。
研究人員發(fā)現(xiàn),,幾乎所有黑猩猩掌握選硬幣的“奧妙”后,,都會(huì)選擇能讓“鄰居”獲益的那枚硬幣。
有無壓力都會(huì)分享
美國(guó)趣味科學(xué)網(wǎng)站8日引述埃默里大學(xué)研究員,、比較心理學(xué)家霍納的話報(bào)道:“對(duì)我來說最重要的發(fā)現(xiàn)是,,黑猩猩與人一樣會(huì)考慮到‘他人’的需要和愿望。”
研究人員還發(fā)現(xiàn)一個(gè)有趣的現(xiàn)象:黑猩猩對(duì)有耐心或有“禮貌”的“鄰居”表現(xiàn)出特別的友好,,愿意幫它們獲得香蕉,。但對(duì)制造噪音、不停請(qǐng)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(rèn)為只會(huì)在壓力下黑猩猩才分享食物,”霍納說,,“我們的實(shí)驗(yàn)得到完全相反的結(jié)論:黑猩猩沒有壓力或壓力小時(shí)會(huì)分享食物,,直接的壓力或威脅會(huì)減少分享,,這可能是負(fù)面情緒作祟。”(生物谷Bioon.com)
DOI:10.1073/pnas.1111497108
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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.