Were bigger brains really smarter?
Bigger is smarter is better. That’s the conventional wisdom for why the human brain gradually became three times larger than the ancestral brain. “But bigger brains were not generally smarter brains,” said neurobiologist William H. Calvin at the American Association for the Advancement of Science meeting in Washington, D.C. on Friday, Feb. 18. “Thanks to the archaeologists, we know that our ancestors went through two periods, each lasting more than a million years, when toolmaking techniques didn’t gradually improve, despite a lot of gradual brain size increase.”