Assuming it has to do with evolution, it would mean that there are clear breeding preferences that where folks with 'smaller brain' mutations' are likely to rep

Assuming it has to do with evolution, it would mean that there are clear breeding preferences that where folks with 'smaller brain' mutations' are likely to reproduce at higher rates than your average person. ( Idiocracy Theory ?) Is it possible that there is long term development of emergent traits in a species, through a process that is not evolution ? I don't buy the domestication hypothesis, because I see no proof that aggression has been disincentivized over what we know about ancient human history. There might be unintended consequences, where those who don't go to war are more likely to live and therefore reproduce, leading to propagation of non warring = low-aggression genes. Lastly: > This may mean that smaller brains are being naturally selected for. Of course, this hypothesis relies heavily on premises that are both not confirmed and highly controversial. When the only reason to reject a hypothesis, is that it is controversial, I am inclined to assign it a higher likelihood.