Almost certainly, it is something biological and genetic. And my guess is that the greater proportion of men at both extremes of the IQ distribution is part of the same pattern. Nature rolls the dice with men more than women. Men go to extremes more than women. It’s true not just with IQ but also with other things, even height: The male distribution of height is flatter, with more really tall and really short men.

Denis Dutton Saturday, February 22, 2014 @ 2:48pm