It was popular during the XXth century to say that most scientific discovery are done by young scientists (under 30). The implicit assumption was that the brain decayed over time, like an apple left to rot. The most recent research contradicts this unavoidable decay. While it was once believed that we progressively lost brain cells as we grew older, we now know that we do grow new neurons all the time (Shors et al., 2012). While some people lose their intellectual edge over time, many older individuals do not experience any intellectual decline (even at age 80). In fact, over the 20th century, older people have taken a greater and greater share of the discoveries (Jones, 2005):
Whereas early research typically showed a decline in productivity after the ages of 40 to 45 years, this decline has been absent in more recent studies. (Stroebe, 2010)
It does seem that older scientists are less likely to come up with new paradigms. But this may have nothing to do with biological decay:
(…) at a relatively early stage both the accumulation of knowledge and the establishment of fixed habits of thought may begin to reduce the ability to create radical new abstract ideations that is key to important conceptual innovations. (Weinberg, 2005)
It seems to me that you have options if you want to plan to be an older intellectual:
- As you grow older, seek to best exploit your existing knowledge: leave radical new ideas to the younger generation.
- From time to time, drastically change your intellectual habits to keep your brain young.