Edge.org has a fascinating article by Michael Gazzaniga, Professor of Psychology and the Director for the SAGE Center for the Study of Mind at the University of California Santa Barbara. The first part of the article appears to be taking from his upcoming book, Human: The Science Behind What Makes Us Unique. It’s a grand celebration of humans and their capabilities. It’s an uplifting read for anyone who, like myself, loves our species.

If that weren’t enough, Gazzaniga goes on to make a case that brain size isn’t everything when it comes to intelligence. This belief is a recent phenomenon. Much of cognitive science is built on the the size-intelligence assumption. But more evidence indicates that structural differences in brains also play an important role in intelligence.

This fact should be somewhat obvious since some species of whales have much larger brains then humans, but don’t display as much intelligence. The reason this was overlooked is because the size assumption was modified to account for body size. This accounts for the relative difference between humans and whales (2% and 1% of body weight belonging to the brain, respectively), but not for the fact that mice brains account for five times the percent of body-weight compared to humans. It is clear that structure plays a role.

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