This is average people in a statistically (hopefully) relevant study.... average people are not creatives. Average people get locked into world views and ideology as they become adults. Average people don't take creative jobs.

Creative people-- that would be an interesting group to study.

As an older engineer, I'm not less creative. I'm slower at writing code, but I need to write a lot less code. In the end I execute at the same speed or faster than younger engineers (Who often seem to take off writing code before they've thought thru the problem and end up shooting themselves in the foot more often than coming up with an idea I hadn't considered. Not that there's anything wrong with them on the balance, just not a slam dunk that younger programmers are more productive.)

I don't see this declining with aging, though my patience with people who can't respond to logic and facts is declining rapidly.