I'm no anthropologist, but it all sounds like a big succession of unfounded claims following from a single fact (the large skull). Brain size is weakly correlat

I'm no anthropologist, but it all sounds like a big succession of unfounded claims following from a single fact (the large skull). Brain size is weakly correlated with IQ, structure is far more important: otherwise, people with size abnormalities should have been geniuses [1] There are mammalians with huge brains out there --- whales and elephants, and they're behind apes cognitively. Modern processors are laid out in a few square centimeters, and not because we are involuntarily constrained by size, quite the opposite -- we're voluntarily constraining them. Making them bigger is actually inefficient: signals couldn't reach the whole die in a single clock cycle, losses increase, and so on. Many diminishing returns architectural changes are required for scaling up [2]. [1] http://en.wikipedia.org/wiki/List_of_tallest_people http://en.wikipedia.org/wiki/List_of_tallest_people -- most of those are sports players, not mathematicians or whatever [2] http://images.anandtech.com/doci/7003/IntelDieSize_575px.png http://images.anandtech.com/doci/7003/IntelDieSize_575px.png -- die size remains fairly constant through generations