What I'm about to post isn't proven fact, but theory, so don't assume it's all correct.
At the University of Pennsylvania (this info is from some time ago) researchers claimed they could identify distinctly two types of left handed
people. There's lefties that mimic the way right-handed people write, and then there's (about 60% of the lefties) the ones that kind of hook their
hand around the pencil so that it points towards the bottom of the page when they write.
Anyway, I'm sure you've all heard of contralateral neural control, in which the left side of the brain controls the right side of the body and the
right side of the brain controls the left side of the body.
Anyway, in most people, the part of their brain that controls language is usually opposite of that which controls writing.
But with the hook-writing lefties, studies have shown that both writing and language are organized on ONE side of the brain, meaning that one side of
the brain is compensating for both sides of the body. This means that hooking lefties neurological organization is different than most other
This extra load for one side of the brain forces hooking lefties brains to work harder than usual, which usually makes their brain fairly capable of
more things (i.e. intelligent), or too weared out (i.e. not so smart). This is one simple explanation, and I have to give credit to Cecil Adams, I
mostly paraphrased his article at www.straightdope.com...
on the issue. I encourage you to visit there for a delightful
array of topics.
-- Zach Jankowski