"I read the same about the early people found on the Canary Islands. Cro-Magnon had a larger brain than all humans today. (Did they have a higher IQ?)"
My head is huge and (judging by an MRI) so is my brain. Unfortunately for me that does not = high IQ.
I just have a huge freekin' cromag noggin. :)
The CroMagnon skulls on average are larger than human average today, but so are those of Neandertal. Obviously there's a great deal of overlap, and the number of samples of the non-extant drifts are small. :')