Human toddlers show markedly better social learning skills compared to their primate cousins, a new study finds.

"We compared three species to determine which abilities and skills are distinctly human," said researcher Esther Herrmann of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

"Social cognition skills are critical for learning," Herrmann said in a news release.

"The children were much better than the apes in understanding nonverbal communications, imitating another's solution to a problem and understanding the intentions of others," she said.

Hermann's study involved 230 subjects -- 100 chimps, 30 orangutans and 100 children.

The children were two-and-a-half years old. That age was picked because the subjects could handle the test's tasks, but they were not old enough to know too much.

The apes resided in sanctuaries in Africa and Indonesia. They ranged in age from three to 21 years.

All the subjects were subjected to the cognitive tests of the Primate Cognition Test Battery.

In areas such as space, quantities and causality, the toddlers and the primates were found to be about equal.

For communication, social learning and theory-of-mind skills, the children scored 74 per cent and the primates only 33 per cent.

As one example, a researcher showed the subjects how to pop open a plastic tube that contained either food or a toy.

The children watched and then duplicated the researcher's actions. The chimps and orangutans tried either breaking the tube or pulling out the contents with their teeth.

Hermann said her study helps provide some insight to the evolution of human cognition.

One theory holds that humans have distinctive "cultural intelligence," she said. Alternatively, some think humans hold an advantage in social cognitive tasks simply because they have more general intelligence.

Human brains are about three times the size of their primate cousins. Humans also have language, symbolic math and scientific reasoning skills.

The full study was published in the Sept. 7 issue of Science, the journal of the American Association for the Advancement of Science.