I must be missing the point, but isn't programming literally cognitive performance?
As you age, your speed and ability to learn new things gradually decline ("fluid intelligence"), but what you've already learned and mastered ("crystallized intelligence"), can remain very strong until the end :)
But have heart! Many people have demonstrated that complex skills (playing musical instruments, and even reading and writing) can be learned well past the age of retirement.
This isn't responsive to my comment. One helpful thing to do is to paste a quote you disagree with or want to ask about.
I think you're asking "Since programming is cognitive performance, is it reasonable to discriminate against those who can't do the work?"
My answer would be yes, if they can't do the work. But out of all the old people I've worked with, only one was a detriment to the team. How many of your coworkers were? How many were old?
The problem with discrimination is that it's easy to believe. People want to believe it. That's why it's easy to say something glib like "don't be afraid, you'll still be able to learn complex skills." That seems rather like saying don't worry, you'll still be able to be a person, since people learn complex skills.
Here's a riddle: How old do you think Satoshi was? He was writing oldschool C++ in 2008. That means he probably learned his trade in the 90's.
As you age, your speed and ability to learn new things gradually decline ("fluid intelligence"), but what you've already learned and mastered ("crystallized intelligence"), can remain very strong until the end :)
But have heart! Many people have demonstrated that complex skills (playing musical instruments, and even reading and writing) can be learned well past the age of retirement.