During a perusal of Instapundit, I came across two (seemingly) unrelated items. The first reports that British skulls appear to have grown 20% above the eyes since the times of the plague:

The two principal differences discovered were that our ancestors had more prominent features, but their cranial vault — the distance measured from the eyes to the top of the skull — was smaller.
Dr Peter Rock, lead author of the study and director of orthodontistry at Birmingham University, told the BBC News website: “The astonishing finding is the increased cranial vault heights.
“The increase is very considerable. For example, the vault height of the plague skulls were 80mm, and the modern ones were 95mm — that’s in the order of 20% bigger, which is really rather a lot.”

Then, by sheer happenstance, no doubt, I clicked over to a tongue-in-cheek quip about this picture:

Bushitler “Shrub” types should feel welcome to flock to my serious question (not mentioned in the BBC skull article) whether the size of British skulls might have more to do with the long-term effects of interbreeding with large-skulled, small-featured foreigners than with blossoming brain function on the isle.