Rambling thoughts. See previous.
Artificially elevated levels of dopamine and dopamine addiction lead to a huge edifice of lies and ritual addiction that is hostile to paradigm shifts, and therefore hostile to genius (and honesty in general). Because genuine entrepreneurial activity is a subset of genius (original post, then Ctrl-F for my comment spree), it is also considered dangerous and quashed under the weight of vast maze-like systems of rituals and regulations. These ritual systems, taken as a whole, constitute The Cathedral as described by neoreactionary types.
Neural networks are much more efficient for perception-like tasks. Because evidence-based judgment, honesty, genius, clear perception of the world, entrepreneurial activity, the middle class in general, etc are all necessary for economic and technological superiority, these interlocking systems give rise to the anticipated class warfare of the high and low vs the middle, where the middle would be exterminated if not for the advantage they confer against external nations through liquidity, technology, and individual fitness through k-selection (vs. group fitness via reproduction rate). Empires have no need for increasing superiority as long as their competitors are successfully repressed.
ADHD cognitive style relies on gray matter volume and scales with brain volume because it depends on the number of nuclei, and connectivity needs are minimal. Thal craniums therefore tend to largeness and spherical expansion. Visuo-spatial IQ also scales with cranial volume. Neurotypical cognitive style relies on white matter and scales with surface area, and therefore melon skulls tend to conical shape, and neurotypical brains in general tend to have more and deeper fissures in the neocortex, and greater general interconnectivity between computation modules and in the corpus callosum.