[jedbrown]

Historically, it would seem like 30 is almost a "sweet spot" for language creation.

* Dennis Ritchie was 27 or 28 in 1969 when C got going.

* McCarthy was about 30 in 1958 for Lisp.

* Sussman was 28 and Steele was 21 in 1975 for Scheme.

* Alan Kay made Smalltalk between 28 and 31.

And while it used to be true that lots of game-changing mathematics was done early, I don't see much of that lately. A huge amount is done by junior faculty and postdocs, but that's usually late 20s and 30s.