There's also a correlation does not imply causation in this. People get worse at acquiring new skills compared to a younger person but there's lots of things th

There's also a correlation does not imply causation in this. People get worse at acquiring new skills compared to a younger person but there's lots of things that change with age outside of physical fitness. For instance, a kid delegates all worries outside of studying and games to the parents. Experts at fields might also underperform in some school subjects in favor of focusing in those they enjoy the most, so they can optimize their time even further. And then we come to the society component. Anyone seeing a 12 year old shipping an app in the app store will omit the fact that the kid might be receiving training from an expert (maybe even a family member) since the age of 4. They won't judge it as "a person who learned programming for 4 years and shipped an app" but "a 12 year old that shipped an app". You might think the difference is semantic but if I were to told you that I was learning programming for 4 years and shipped an app you'd be like "what do you want now, a cookie? You're 30". People who believe that over a certain age you're not gonna do anything good might consider suggesting software development as an activity to a 40 year old as a hobby, not as a profession. I cannot imagine them telling the same thing to a child. Don't get me wrong. I do believe that physical change exists and that my 15-year old self would run circles around me. But everyone gives advice on the grounds of seeking masters, not professionals. Translate that belief to the hiring process and it's easy to see where ageism starts. Someone might say that hiring a 40 year old who wants a junior developer position is "settling for less" in spite of the fact that your product can be shipped just as efficiently.