Is that chart on the bottom of the profile his performance improvement over time? That would be pretty cool, like 3 years ago he was just a normal programmer (a 13 year old programmer, though)... Or is it accumulated points?

It's the former.

I really don't find it insane. Young people have much more powerful brains, they just have to learn programming at a younger age. I did it, and I find myself (and others who learnt programming as kids) better programmers than those who learnt in college.