The human advantage: a new understanding of how our brain became remarkable

This difference reflects what I have called the “primate advantage”:’ because of the way a primate brain is put together, a much larger number of neurons fits into a cerebral cortex of similar size to that of a rodent—which is a major asset when volume is at a premium, as we’ll see later in this chapter.

The human advantage, I would say, lies in having the largest number of neurons in the cerebral cortex that any animal species has ever managed—and it starts by having a cortex that is built in the image of other primate cortices: remarkable in its number of neurons, but not an exception to the rules that govern how it is put together. Because it is a primate brain—and not because it is special—the human brain manages to gather a number of neurons in a still comparatively small cerebral cortex that no other mammal brain, that is, still smaller than 10 kilograms, would with a viable be able to muster.

As it turns out, there is a simple explanation for how the human brain, and it alone, can be at the same time similar to others in its evolutionary constraints, and yet so different to the point of endowing us with the ability to ponder our own material and metaphysical origins. First, we are primates, and this bestows upon humans the advantage of a large number of neurons packed into a small cerebral cortex. And second, thanks to a technological innovation introduced by our ancestors, we escaped the energetic constraint that limits all other animals to the smaller number of cortical neurons that can be afforded by a raw diet in the wild. So what do we have that no other animal has? A remarkable number of neurons in the cerebral cortex, the largest around, attainable by no other species, I say. And what do we do that absolutely no other animal does, and which I believe allowed us to amass that remarkable number of neurons in the first place? We cook our food. The rest—all the technological innovations made possible by that outstanding number of neurons in our cerebral cortex, and the ensuing cultural transmission of those innovations that has kept the spiral that turns capacities into abilities moving upward—is history.