From Scientific American:
Does creativity decline with age?
This question has attracted scientific research for more than a century. In fact, the first empirical study of this issue was published in 1835. Thus, I can offer a confident answer: not quite! At least not if creativity is assessed by productivity or by making original and valuable contributions to fields such as science and art. By that measure, output first increases in our mid-20s, climaxes around our late 30s or early 40s, and then undergoes a slow decline as we age. A person’s single best work tends to appear at roughly the same age as their output peaks. But their expected creative productivity at 80 will still be about half of what it was at that high point. Whether you view that as a significant drop or not depends on whether you see the glass as half empty or half full.
. . . .
First, the precise relation between age and creativity depends on the domain. Some creative types—such as lyrical poets and mathematicians—tend to have early peaks and relatively rapid declines, whereas others—among them, historians and philosophers—are prone to later peaks and gradual, even negligible declines.
Second, creative people vary greatly in total lifetime productivity. At one extreme are the one-hit wonders, who make single contributions; their creativity is almost over before it begins. At the other end of the spectrum are highly prolific creators who make dozens, if not hundreds, of contributions and who are often still going strong well into their 60s and 70s, if not beyond.
. . . .
One striking implication of these results is that it seems unlikely that creative declines are caused simply by aging brains. If that were the case, it would be hard to explain why the creative path differs by domain, lifetime output, or the time someone embarks on his or her career. After all, late bloomers reach creative peaks at ages when early bloomers are past their prime.
Link to the rest at Scientific American