Mendes Natacha, Rakoczy Hannes, Call Josep
Max-Planck-Institute for Evolutionary Anthropology, Department of Developmental and Comparative Psychology, Deutscher Platz 6, D-04103, Leipzig, Germany.
Cognition. 2008 Feb;106(2):730-49. doi: 10.1016/j.cognition.2007.04.007. Epub 2007 May 29.
Developmental research suggests that whereas very young infants individuate objects purely on spatiotemporal grounds, from (at latest) around 1 year of age children are capable of individuating objects according to the kind they belong to and the properties they instantiate. As the latter ability has been found to correlate with language, some have speculated whether it might be essentially language dependent and therefore uniquely human. Existing studies with non-human primates seem to speak against this hypothesis, but fail to present conclusive evidence due to methodological shortcomings. In the present experiments we set out to test non-linguistic object individuation in three great ape species with a refined manual search methodology. Experiment 1 tested for spatiotemporal object individuation: Subjects saw 1 or 2 objects simultaneously being placed inside a box in which they could reach, and then in both conditions only found 1 object. After retrieval of the 1 object, subjects reached again significantly more often when they had seen 2 than when they had seen 1 object. Experiment 2 tested for object individuation according to property/kind information only: Subjects saw 1 object being placed inside the box, and then either found that object (expected) or an object of a different kind (unexpected). Analogously to Experiment 1, after retrieval of the 1 object, subjects reached again significantly more often in the unexpected than in the expected condition. These results thus confirm previous findings suggesting that individuating objects according to their property/kind is neither uniquely human nor essentially language dependent. It remains to be seen, however, whether this kind of object individuation requires sortal concepts as human linguistic thinkers use them, or whether some simpler form of tracking properties is sufficient.
发展研究表明，非常年幼的婴儿纯粹基于时空依据来区分物体，而（最晚）从大约1岁起，儿童就能够根据物体所属的类别以及它们所具有的属性来区分物体。由于发现后一种能力与语言相关，一些人推测它是否本质上依赖于语言，因此是人类独有的。现有的针对非人类灵长类动物的研究似乎与这一假设相悖，但由于方法上的缺陷，未能提供确凿的证据。在本实验中，我们着手用一种改进的手动搜索方法来测试三种大型猿类的非语言物体区分能力。实验1测试了时空物体区分能力：受试者同时看到1个或2个物体被放入一个它们能够够到的盒子里，然后在两种情况下都只找到了1个物体。在取出这1个物体后，当受试者看到的是2个物体时，他们再次伸手的频率明显高于看到1个物体时。实验2仅根据属性/类别信息测试物体区分能力：受试者看到1个物体被放入盒子里，然后要么找到了那个物体（预期情况），要么找到了一个不同种类的物体（意外情况）。与实验1类似，在取出这1个物体后，受试者在意外情况下再次伸手的频率明显高于预期情况。因此，这些结果证实了先前的研究发现，即根据物体的属性/类别来区分物体既不是人类独有的，也不是本质上依赖于语言的。然而，这种物体区分是否需要人类语言思考者所使用的分类概念，或者某种更简单的追踪属性的形式是否就足够了，还有待观察。
