Beran Michael J, Beran Mary M
Language Research Center, Georgia State University, USA.
Psychol Sci. 2004 Feb;15(2):94-9. doi: 10.1111/j.0963-7214.2004.01502004.x.
Four chimpanzees were highly accurate in selecting the larger of two concurrent accumulations of bananas in two opaque containers over a span of 20 min. One at a time, bananas were placed into the containers, which were outside the chimpanzees' cages. The chimpanzees never saw more than one banana at a time, and there were no cues indicating the locations of the bananas after they were placed into the containers. The performance of these animals matched that of human infants and young children in similar tests. The chimpanzees were successful even when the sets to be compared were sufficiently large (5 vs. 8, 5 vs. 10, and 6 vs. 10) to cast doubt on the possibility that the chimpanzees were using an object file mechanism. These chimpanzees are the first nonhuman animals to demonstrate extended memory for accumulated quantity.
在20分钟的时间里，四只黑猩猩能够高度准确地从两个不透明容器中同时堆积的香蕉中选出数量较多的那一堆。香蕉一次放入一个容器，容器放置在黑猩猩笼子外面。黑猩猩一次最多只能看到一根香蕉，而且香蕉放入容器后没有任何线索表明其位置。这些动物在类似测试中的表现与人类婴幼儿相当。即使要比较的数量足够大（5对8、5对10和6对10），足以让人怀疑黑猩猩是否使用了客体档案机制，它们依然能够成功完成任务。这些黑猩猩是首批证明对累积数量具有长期记忆的非人类动物。
