As part of the study, Esther Herrmann and her colleagues compared 105 2-year-old human children, 106 chimpanzees and 32 organutans in a comprehensive battery of physical and social cognitive tests.
Findings revealed that while all were about equal in the physical cognitive skills of space, quantities and causality, in the social skills of communication, social learning and theory-of-mind skills, the children were correct in about 74 percent of the trials, compared to the two ape species which were correct only about 33 percent of the time.
In one example of the social learning tasks, a researcher demonstrated how to pop open a plastic tube to retrieve food or a toy inside. The children watched and copied. The chimps and orangutans did not imitate the researcher and instead tried to break the tube or pull the contents out with their teeth.
Herrmann said the findings supported the cultural intelligence hypothesis, that humans had distinctive social cognitive skills to interact in cultural groups.
'We compared three species to determine which abilities and skills are distinctly human. 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,' said Herrmann.
'Social cognition skills are critical for learning,' she said.
She further said this was the first comprehensive test comparing social and physical skills of children, chimpanzees and orangutans, adding that the results provided important insight into the evolution of human cognition.
The children in the test were in the age group of 2.5-3. The apes ranged in age from 3 to 21.
The study appears in the Sept 7 issue of the journal Science.