Human Cognition

Abstract Approximately 6 to 8 million years ago, a population of African apes began evolving into the species known today as Homo sapiens. The process of speciation resulted in the emergence of a number of unique characteristics along the way, including bipedal locomotion, the loss of much body hair, and the making of stone tools. The most dramatic developments, however, occurred during the latter stages of this period as human beings began to create a bewildering array of cognitive products not seen in other primate species: such things as natural languages, symbolic art, multifunctional technologies, higher mathematics, and cultural institutions such as governments and religions. One of the deepest mysteries in the evolution of primate cognition is how it happened that this particular species came to specialize so dramatically in the complex cognitive processes that are embodied in these products. The basic puzzle is that, although 6-8 million years is a very long time historically, it is a very short time evolutionarily. Thus, H. sapiens is as genetically similar to its nearest primate relatives, Pan troglodytes and P. paniscus, as horses are to zebras, lions are to tigers, and rats are to mice, sharing something on the order of 98% of their genetic profiles (King & Wilson, 1975). Given this evolutionary proximity, any cognitive differences that we observe must be based on a very delimited set of biological adaptations. In attempting to characterize human cognition as a special case of primate cognition, therefore, the challenge is to find a small difference that made a big difference-a small change, or set of changes, that transformed the process in fundamental ways.