Paul Manger of Johannesburg’s University of the Witwatersrand says the super-sized brains of dolphins, whales and porpoises are a function of being warm-blooded in a cold water environment and not a sign of intelligence. “We equate our big brain with intelligence. Over the years we have looked at these kinds of things and said the dolphins must be intelligent,” he said….
They are widely regarded as one of the smartest mammals. But Manger, whose peer-reviewed research on the subject has been published in “Biological Reviews of the Cambridge Philosophical Society”, says the reality is different. Brains, he says, are made of neurons and glia. The latter create the environment for the neurons to work properly and producing heat is one of glia’s functions. “Dolphins have a superabundance of glia and very few neurons … The dolphin’s brain is not made for information processing it is designed to counter the thermal challenges of being a mammal in water,” Manger said.
As a couple of Randy’s commenters note, other measures of intelligence seem to tell a different story.