Rumbaugh D M, Savage-Rumbaugh S, Hegel M T
J Exp Psychol Anim Behav Process. 1987 Apr;13(2):107-15.
In this research, we asked whether 2 chimpanzee (Pan troglodytes) subjects could reliably sum across pairs of quantities to select the greater total. Subjects were allowed to choose between two trays of chocolates. Each tray contained two food wells. To select the tray containing the greater number of chocolates, it was necessary to sum the contents of the food wells on each tray. In experiments where food wells contained from zero to four chocolates, the chimpanzees chose the greater value of the summed wells on more than 90% of the trials. In the final experiment, the maximum number of chocolates assigned to a food well was increased to five. Choice of the tray containing the greater sum still remained above 90%. In all experiments, subjects reliably chose the greater sum, even though on many trials a food well on the "incorrect" tray held more chocolates than either single well on the "correct" tray. It was concluded that without any known ability to count, these chimpanzees used some process of summation to combine spatially separated quantities. Speculation regarding the basis for summation includes consideration of perceptual fusion of pairs of quantities and subitization.
在这项研究中，我们探究了两只黑猩猩（黑猩猩属）能否可靠地对数量对进行求和，以选出总数更大的那一组。实验让黑猩猩在两盘巧克力之间进行选择。每盘都有两个食物格。要选出巧克力数量更多的那一盘，就需要对每盘食物格中的巧克力数量进行求和。在食物格中巧克力数量从0到4块的实验里，黑猩猩在超过90%的试验中都选择了求和后数值更大的那一盘。在最后一个实验中，分配给一个食物格的巧克力最大数量增加到了5块。选择总和更大的那一盘的比例仍保持在90%以上。在所有实验中，尽管在许多试验里，“错误”那一盘上的一个食物格中的巧克力比“正确”那一盘上的任何一个单独食物格中的巧克力都多，但黑猩猩仍可靠地选择了总和更大的那一盘。研究得出结论，在没有任何已知计数能力的情况下，这些黑猩猩运用了某种求和过程来合并空间上分离的数量。关于求和基础的推测包括对数量对的感知融合以及数感的考虑。
