Tots top chimps in social abilities

Study: 'Cultural intelligence' sets apart humans

Toddlers as young as 2 1/2 years old have better social skills than their nearest primate relatives, chimpanzees, and display an innate "cultural intelligence" unique to humans, according to a study published Friday in the journal Science.

Lead author Esther Hermann of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said the research showed humans had distinctive abilities to understand non-verbal communication, imitate another's solution to a problem and to read the intentions of others.  These skills were necessary for people to acquire mathematics and language, and to participate in cultural groups with institutions and practices, she said.

The report said the toddlers' superior performance on a battery of tests provided fresh insight into the evolution of human cognition, suggesting the demands of living in a complex society drove development of the human brain.

Humans have brains roughly three times larger than those of chimps, and scientists have long tried to understand the forces that caused the two species to diverge 4 million to 7 million years ago.  One theory holds that larger brains endowed humans with a greater memory, faster learning abilities and an improved capacity for planning.

Such skills might have allowed early humans to better forage for seasonal berries and fruits.

But many biologists and anthropologists consider that explanation incomplete.  They believe that brain size correlates to a species' need to manage social relationships with family members, allies and rivals.  Recent studies have found that apes and monkeys -- whose brains are large relative to their physical size -- share a range of behaviors with humans, suggesting that such traits as cooperation, empathy and using simple tools go back to a common ancestor.

Outdone by apes

Apes and children fared equally well on tests of how they understood their physical world.  Occasionally, apes did better.  For example, chimps and preschoolers could tell at a glance which dish contained a few more raisins.  But when the dishes were covered and extra raisins dropped in, the apes kept better track of which dish had more.