Subject: Do children's heads stop growing at age three?

I have a good friend whose daughter (aged 5 1/2) has a very small head. She is
quite petite over all, so her head fits her body. She is bright, energetic, and
full of ideas and opinions. However, my friend's husband worries constantly
because of her small head. He is convinced that our heads stop growing at age 3
and that she will end up a "pin-head" with a learning disability (worse case) or
at least will be teased for life because she will be out of proportion. We have
been unable to disabuse him of this idea, although just looking at most adults
has me pretty convinced that our three-year-old necks would have snapped if our
heads had reached full size at that age. He is basing this idea on something he
heard or read somewhere. I did find one reference that said that "the head
reaches almost its entire size by age 1."
(http://www.chop.edu/consumer/your_child/wellness_index.jsp?id=-9390) 
I'm wondering what they mean and how they define that.  Thanks for your help!

Re: Do children's heads stop growing at age three?