Numerical Perception of Monkeys

We all are aware of the numerous abilities of monkeys and their close mammalian features to humans. One particular feature that was recently explored and researched was a monkey’s advanced abstract numerical concepts. Scientists at Duke University played the sound of a natural “coo” call made by unfamiliar monkeys to the experimental monkeys. The scientists played the “coo” call from either two or three monkeys and had two videos playing simultaneously; one with two monkeys and the other with three. The researchers found that monkeys overwhelmingly chose to look at the video image that matched the number of monkeys they were hearing.
One might ask why a monkey’s ability of perception of numerical values tied to the sense used to perceive the number would be an advantage to the animal. Living in the wild and having territory to defend, it is a remarkable advantage for the monkey.
Out in the wild, a monkey might hear different monkeys vocalizing and not yet seeing the other monkeys, the monkey will not know how many there are. Within territorial disputes, the monkey will want to know how many monkeys are about to enter in it’s boundaries to make sure the territory can be properly defended.
This study provided evidence to the scientists that monkeys detect a correspondence in number between two different sensory modalities, and that implicated that language is not necessary to represent number abstractly.
http://www.dukenews.duke.edu/2005/06/BrannonCurrBio.html
Caroline Collins