ABSTRACT
Taking a comparative perspective on human cognition presents an immediate puzzle. Human beings shared an ancestor with their nearest primate relative, the chimpanzee, a mere 6 to 8 million years ago-a very brief time evolutionarily. But the cognitive skills of the two species seem very different. Just to highlight the obvious, human beings have whatever cognitive skills are necessary to create products such as languages, complex cumulative technologies, and social institutions-whereas, to our knowledge, chimpanzees do not. The problem is that there simply has not been enough evolutionary time for very large differences of cognitive processes to have evolved. The general solution to this puzzle must be some small difference of cognitive process that makes a big difference in the cognitive products that may be created.
