Researchers at Duke University have demonstrated that monkeys have the ability to perform mental addition, and that they performed about as well as college students given the same test.
Current evidence has shown that both humans and animals have the ability to mentally represent and compare numbers. For instance, animals, infants and adults can discriminate between four objects and eight objects.
However, until now it was unclear whether animals could perform mental arithmetic.
Elizabeth Brannon and Jessica Cantlon of the Duke Center for Cognitive Neuroscience said the findings shed light on the shared evolutionary origins of arithmetic ability in humans and non-human animals.
That monkeys and humans share the ability to add suggests that basic arithmetic may be part of a shared evolutionary past.
Earlier this month, Japanese researchers pitted young chimps against human adults in tests of short-term memory, and overall, the chimps won.
The study was published in the December 2007 issue of the journal PLoS Biology.