Human and animal cognition: Continuity and discontinuity

Microscopic study of the human brain has revealed neural structures, enhanced wiring, and forms of connectivity among nerve cells not found in any animal, challenging the view that the human brain is simply an enlarged chimpanzee brain. On the other hand, cognitive studies have found animals to have abilities once thought unique to the human. This suggests a disparity between brain and mind. The suggestion is misleading. Cognitive research has not kept pace with neural research. Neural findings are based on microscopic study of the brain and are primarily cellular. Because cognition cannot be studied microscopically, we need to refine the study of cognition by using a different approach. In examining claims of similarity between animals and humans, one must ask: What are the dissimilarities? This approach prevents confusing similarity with equivalence. We follow this approach in examining eight cognitive cases - teaching, short-term memory, causal reasoning, planning, deception, transitive inference, theory of mind, and language - and find, in all cases, that similarities between animal and human abilities are small, dissimilarities large. There is no disparity between brain and mind. © 2007 by The National Academy of Sciences of the USA.