I'm quite willing to believe that human brains do Weird Stuff with respect to reusing circuits and development, but I still don't see how they concluded "the skill encourages the brain state" by disproving "the brain state encourages the acquisition of the skill."

It would be ethically difficult to randomly assigned children to groups (A) taught to read versus (B) forced to remain illiterate while ensuring both groups had the same number of people's faces in their social circles.

IIRC the author compares brain scans and recognition abilities of children of hunter gatherers that where sent to school vs same age relatives that were not. I’m bringing this up from memory now and I’m not so sure of this, but this claim stems from some studies of the author