[ELI5] How do the wrinkles in the brain influence intelligence?

Question

Why smoothness =less intelligent

In: 0

Answer 1

Other people have explained the grey matter part, but the reason why the wrinkles form in the first place is because the skull is only so big. It can only hold so much volume.

So if you want more surface area on something constrained within that volume you need to wrinkle the surface. And that’s what the evolutionary process ended up doing.

You could make the skull bigger, to accomodate a larger smooth brain with a surface area equal to a wrinkled brain. But brains use a lot of energy and need a lot of protection. That would have to be factored in. And then there’s the increased weight of a bigger brain and skull which would mean changes to the neck and musculature. The easiest path is wrinkles.

Answer 2

Other people have explained the grey matter part, but the reason why the wrinkles form in the first place is because the skull is only so big. It can only hold so much volume.

So if you want more surface area on something constrained within that volume you need to wrinkle the surface. And that’s what the evolutionary process ended up doing.

You could make the skull bigger, to accomodate a larger smooth brain with a surface area equal to a wrinkled brain. But brains use a lot of energy and need a lot of protection. That would have to be factored in. And then there’s the increased weight of a bigger brain and skull which would mean changes to the neck and musculature. The easiest path is wrinkles.