That's an interesting observation.
Let's take a sport.
Say tennis.
let's take competitive tennis, played by professionals.
At the world level, tennis is both a physical and mental game where you are trying to outguess your opponent in the context of a rally.
Roger Federer, who is now 36 is a rare exception in his ability to stay on top at his age.
The sport requires intense focus, both mental and physical.
This focus does goes down beyond a certain age.
You could argus that there is a difference between physical and mental focus ...
> You could argus that there is a difference between physical and mental focus ...
Not only that, developing software is generally a "slow" task, not constant decision making in spans of milliseconds like in a "fast" sport you mentioned. If you want to compare, try a "slow" sport like golf, does your observation still hold true?
In engineering tasks you also gain a lot of productivity (at least if your metrics aren't crap, might be often a problem here) from years and decades of building up experience and knowledge. Moreover this doesn't get lost to a huge degree if you pause 1-2 years, not like physical training which goes away quickly and is hard to build up again.
I think what could play a role here is that older people may often be less focused on the job because that focus shifts to other things in life like e.g. family.
I have to say I have more than just some experience here... Quick decision times decline VERY slowly; that is to say the amount of time it takes to make the correct decision as opposed to just reacting to a situation. You are confusing the amount of strength it takes to play at the top level and still have enough in the tank to not lose focus.
FWIW I'm not talking out of my hat here, I "played" a very thought intensive sport in my younger day and was one of the top guys in the US on any given day. I still have ridiculously quick decision times and the concentration of a Monk with ADD when I drive, But there's no way my bod could compete with a my former self of 20 years ago. I'm in pretty good shape now but I'm not a World class athlete anymore.
Aging and tennis (and sports in general) reflects real, physical deteriorations that aren't in play -- at least not in the same domain -- with mental processes.
