I read an absolutely fascinating paper that suggested a further connection with crime: http://www.lse.ac.uk/collections/MES/pdf/JRP2003.pdf. Basically, the paper's thesis was that males are biologically driven to do extraordinary things when young in order to impress females. For people who have the ability, this can take the form of scientific achievement, or entrepreneurship, or arts or music. For people who don't have the ability to succeed in "socially acceptable" fields, it usually takes the form of crime. The age curves themselves look very similar, and they don't see similar distributions with females.

After a man has children, the odds are significantly lower that he'll contribute some world-changing discovery. This is not because his ability level has decreased - Marc's article suggests that quality of work remains constant. Rather, it's because he has no reason to. He's already reproduced, and likely found a lifetime mate. His children's genetic legacy is set in stone. There's no reason for him to expend the extra energy needed to perform at the top of his game.

Curiously, men that continue to produce at top-of-the-field levels also seem to have multiple successive wives/lovers. Look at Rudy Giuliani, Richard Feynman, Albert Einstein, Benjamin Graham, etc. Perhaps they remain geniuses because they see the reproductive game as not over yet, and hope to continue to impress younger, more beautiful women.