Adaptation and the Brain. Oxford Series in Ecology and Evolution.

What does this tell us about the brain sizes and efficiencies of herring brains as opposed to human brains? The immediate inference is that Neanderthals were smarter than humans - after all, the human brain is hugely bigger than the brain of small, less intelligent vertebrates such as the shrew, let alone the sizes of invertebrate brain. If, in the natural course of things, a shrew can feed itself more efficiently than a human, what then does its smaller brain size signify?. [Extracted from the article]