DD has been 90% height, 95% weight, 164% head circumference for a long time. I was heartbroken when we'd go out and hear *every single day*, "What a beautiful baby BOY!" to my DD, even when dressed in pink from head to toe. She looked like Charlie Brown until her hair grew in. :-(

The autism link is well documented for babies with smallish heads that suddenly grow to a giant size.

Here's another study on head circumference and IQ:

http://pediatrics.aappublications.org/cgi/content/full/118/4/1486

Published online October 2, 2006
PEDIATRICS Vol. 118 No. 4 October 2006

The Influence of Head Growth in Fetal Life, Infancy, and Childhood on Intelligence at the Ages of 4 and 8 Years


Of couse it can just be hereditary, like big feet...

P.S. My FIL had a notoriously monster cranium through adulthood. He had to special order a motorcycle helmet which looked quite a bit like those original, old scuba globes. For what it's worth, he did have the highest score ever recorded (at the time) on his specialty medical board exams. He also definitely fell into the category of "clutter prone and easily frustrated." LOL!