A conventional approach to chimpanzee cognition. Response to M.D.Hauser (2000)
Nobuyuki Kawai, Tetsuro Matsuzawa
Thanks to the failure of Clever Hans, the findings of numerical competence in non-human animals have been treated with caution by comparative psychologists. However, as summarized by Marc Hauser [Hauser, M.D. (2000) Homologies for numerical memory span? Trends Cognit. Sci. 4, 127–128]1 , a growing body of evidence for non-human animals' numerical competence has been demonstrated, not only in primates but also in rodent and even avian species.
Besides numerical abilities, similarities in many other cognitive processes are found between humans and other animals. For instance, Wright and his colleagues have found evidence for both the primacy and the recency effects in the serial recognition task, in monkeys and pigeons as well as humans2 . Despite several such parallels, however, comparative psychologists still seem wary of assuming the same underlying cognitive mechanisms in humans and animals. This is because a similarity in performance among different species can be superficial, and does not always indicate a shared cognitive process. It may be that the same task can be solved in qualitatively different ways by different species.