Some people cannot say how much it is two plus two, but chimps can! After having recently humiliated college students in tests of short term memory made by a Japanese team, chimps keep coming with surprises.
A new research made at Duke University and published on the on-line journal PLoS Biology found that chimps had similar mental addition to college students, a discovery pointing to the fact that non-verbal math skills might not be a specific human trait. Other researches had revealed that monkeys can pair numbers of objects,
compare numbers and choose the higher number from two sets of objects.
"This is the first study that looked at whether or not they could make explicit decisions that were based on mathematical types of calculations", said author Jessica Cantlon, a cognitive neuroscience researcher at Duke.
"It shows when you take language away from a human, they end up looking just like monkeys in terms of their performance", said Cantlon.
The tests were made on two chimpanzee females and 14 Duke University students. They had to mentally add two sets of dots flashed briefly on a screen. The subjects had to choose the right answer out of two offered choices appearing on a different screen.
The students were not forbidden to count or verbalize while accomplishing the task, and they had to do it as quickly as possible. The average response time for both chimps and humans was 1 second, and the results very similar.
This type of ape studies help us in "discovering where the sophisticated human mind comes from", said Cantlon.
This discovery points that advanced human maths have a lot to do with speech, which permits counting and advanced calculations.
"I don't think language is the only thing that differentiates humans from non-human primates, but in terms of math tasks, it is probably the big one", said Cantlon.