An investigation of number-concept appreciation in a rhesus monkey

Abstract

In order to determine if nonhuman primates have some type of number-concept appreciation, the ability to form a concept of the third object in a row of three, four, five, six or seven objects was studied in an adolescent rhesus monkey. The problem was presented to the subject in a Wisconsin General Test Apparatus. Square wooden blocks, placed on a 45-hole formboard were used as the experimental stimuli. Position of rows of blocks was varied, either being placed in the center of the first row or randomly on the formboard. The subject learned to discriminate the third block in a row of blocks in a total of 62 days. The results of the present experiment indicate that monkeys can learn the concept of third. These results agree with those of other studies of number concept in nonhuman primates and lend further support to the idea that nonhuman primates have at least some type of number appreciation.