An interesting quote from Havelock Ellis' Man and Woman which ties in to my earlier post on Cranial size and shape:
The measurements of members of the British Association at Bath a few years ago showed that the men were very greatly more brachycephalic than the women; while 18.8 per cent of the women were dolichocephalic against only 12.1 per cent. of the men, only 2.2 per cent of the women were hyperbrachycephalic against 9.1 of the men. There is evidently a fallacy here, and I think it is to be found in the fact that unusual intellectual ability seems to be very frequently associated with brachycephalism, and a brachycephalic head has a greater capacity than a dolichocephalic head of the same circumference; while the men would number of a considerable proportion of individuals of marked ability, the women would more usually simply be the wives or relatives of the men.
On the same topic in Manual of Mental and Physical Tests, by Guy Montrose Whipple Ph.D.
The Criminal, his personnel and environment, by August Drahms: