Interesting, and surprising, because most scientists in modern times are still just implementing their advisors' ideas at 27.<p>I'd believe that they peak in "freshness" in their late 20s and early 30s, but I think the peak of competence is later. This is how art works, as well. For example, Shakespeare presumably developed his fame shortly after Richard III, which he wrote at 28; but he did his best work (the "five tragedies", and his better comedies) in his late 30s and early 40s.