The Tyranny of the Left

[Maxmars]

...

I saw a study suggesting that an explanation for the thicker corpus callosum in women might be due to the smaller brain size. I'm not sure why that would be though.

Perhaps it's as straight forward as skull 'total volume' .. but I bet that's overly simplistic.  I've never really dug into this before. I had heard that there is considerable variation between people in exactly how the brain "sits" in the brain pan, some have use more room, others are not so jam packed - and all that without significantly impacting mental function.  But I'm really only recounting what I may be misremembering.