Russell Yvan I, Call Josep, Dunbar Robin I M
British Academy Centenary Research Project, School of Biological Sciences, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK.
Behav Processes. 2008 May;78(1):108-11. doi: 10.1016/j.beproc.2007.10.009. Epub 2007 Nov 1.
'Image scoring' occurs when person A monitors the giving behaviour of person B towards person C. We tested for 'image scoring' in chimpanzees, bonobos, gorillas, and orangutans. Subjects passively observed two types of incident: (i) a 'nice' person gave grapes to a human beggar, and (ii) a 'nasty' person refused to give. The subject witnessed both incidents in succession (but was unable to obtain the grapes). Shortly after, the ape had an opportunity to approach one or both human actors (nice/nasty), both of whom were now sitting side-by-side holding grapes. However, neither human offered their grapes if approached. The subject's expectation of which human was more likely to offer food was measured by comparing the proportion of time that subjects spent near each person. Chimpanzees (n=17) spent significantly more time at the 'nice' window compared to 'nasty'. Also, preference for 'nasty' declined as trials progressed. Results for other apes were not significant.
当A观察B对C的给予行为时，就会出现“形象评分”。我们对黑猩猩、倭黑猩猩、大猩猩和猩猩进行了“形象评分”测试。实验对象被动地观察了两种事件：（i）一个“友善”的人给了一个人类乞丐葡萄，以及（ii）一个“讨厌”的人拒绝给予。实验对象依次目睹了这两种事件（但无法获得葡萄）。不久之后，猿类有机会接近其中一个或两个人类参与者（友善的/讨厌的），这两个人现在并排坐着拿着葡萄。然而，如果被接近，两个人都不会主动提供葡萄。通过比较实验对象在每个人旁边花费的时间比例，来衡量他们对哪个更有可能提供食物的人类的预期。与“讨厌”的人相比，黑猩猩（n = 17）在“友善”的窗口花费的时间明显更多。此外，随着试验的进行，对“讨厌”的人的偏好下降。其他猿类的结果不显著。
