I guess with the concept of an upper age limit, there are some things to think about. Not everyone mentally declines at the same rate or even at all. The same with physical issues.
I know people much younger who make me wonder how in the hell they found their way out of their house in the morning. Yet my grandmother was into her 80s and sharp as a tack. An aunt I recently visited is in her mid-80s (and physically quite unwell) and I would put her memory and intelligence up against almost anyone. She's been blind for decades so her memory is super important as is her attention to detail.
There will always be outliers. Younger and older. But as for age alone being the determining factor, I am not real good with that.
I know people much younger who make me wonder how in the hell they found their way out of their house in the morning. Yet my grandmother was into her 80s and sharp as a tack. An aunt I recently visited is in her mid-80s (and physically quite unwell) and I would put her memory and intelligence up against almost anyone. She's been blind for decades so her memory is super important as is her attention to detail.
There will always be outliers. Younger and older. But as for age alone being the determining factor, I am not real good with that.