racists!
just kidding.

Not to beat a dead horse- but I agree its because of the enviroment.
Japanese people don't have bigger brains- they are just conditioned to learn. They usually have stricter parents who get them involved in a lot of stuff.
I remember all the piano competitions I've been to. The most trained players are ALWAYS asian.
These are 10 and 11 year olds who play complicated stuff...but then again their parents make them go to lessons 3 or 4 times a week....