A unique study comparing the abilities of human toddlers to chimpanzees and orangutans found that 2-year-old children have social learning skills superior to the apes, researchers said on Thursday.
In one social learning test, a researcher showed the children and apes how to pop open a plastic tube to get food or a toy contained inside. The children observed and imitated the solution. Chimpanzees and orangutans, however, tried to smash open the tube or yank out the contents with their teeth.
European scientists gave a battery of cognitive tests lasting three to five hours separately to 105 2-year-old children, 106 chimpanzees and 32 orangutans over two weeks.
"Using these multiple tests allows us to pinpoint where are the similarities and where are the differences," researcher Josep Call of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany told reporters.
The researchers believe their findings provide insight into the evolution of human cognition. People’s brains are three times larger than those of the closest primate relatives.
"This is the first time that anything like this has been done," added Max Planck Institute researcher Esther Herrmann.
Chimpanzees and orangutans are among the great apes. Chimps are considered the closest genetic relatives to people, with orangutans a bit more distantly related.
The researchers found that the children were far more advanced than the chimps and orangutans in understanding nonverbal communications, copying another person’s solution to a problem and understanding the intentions of others.
The apes were closer to the toddlers in some other tests like those measuring "physical cognitive skills" involving things like quantities and causality, the researchers found.
"Young human children who had been walking and talking for about one year, but who were still several years away from literacy and formal schooling, performed at basically an equivalent level to chimpanzees on tasks of physical cognition, but far outstripped both chimpanzees and orangutans on tasks of social cognition," they wrote in the journal Science.
"We may thus think of 2-year-old children’s cognitive development in the physical domain as still basically equivalent to that of the common ancestor of humans and chimpanzees some 6 million years ago … but their social cognition as already well down the species-specific path."
The apes performed the tests in animal sanctuaries in Africa and Indonesia.
In another study in the same journal, other researchers said they showed that apes and monkeys do possess skills like figuring out the intentions of others. They studied cotton-top tamarins, rhesus macaques and chimpanzees.