Locates human cognitive advantage in social knowledge exchange rather than general problem solving alone.
The authors ran two-and-a-half-year-old children, chimpanzees and orangutans through the same battery of tasks, the Primate Cognition Test Battery. Half the tasks cover the physical world: space, quantity, causality. Half cover the social world: social learning, communication, reading intentions.
On the physical tasks the children and the apes scored about the same. On the social tasks the children scored far higher. The gap is domain-specific, which is the whole result.
A general-intelligence account predicts a uniform gap across both halves. This one is concentrated in the machinery for getting knowledge out of other minds. That machinery is what makes a culture able to accumulate anything.