Stile writes:
The initial question is "does a person lose objectivity as they grow older?"
Absolutely. I've seen too many examples of the elderly being irrational while being confronted by evidence. It's kinda sad to think I'll be like that one day.
More commonly described as "becoming senile," losing objectivity seems to happen more to the elderly.
You don't need to be senile to lose objectivity.
Let me tell you a short story about my own experience to tell you what I mean. When I was in college, a professor approached me and told me he was going to spend the summer in England teaching a summer class at a university there. His wife, a retired science teacher, didn't seem to like the idea of couple of young people staying in her multi-million dollar home. Fair enough, I thought. My friends and I needed a place to stay in the summer to do our research and save up money. We assured them that we would take care of their home. And we did. Long story short, there was one incident that shows how one could lose objectivty.
My friend, a body builder, and I were cleaning the basement. We thought we'd clean up the place for them. Anyway, while we were cleaning, a big black man busted through the door right in front of us. We stood there for a couple seconds staring at him. He then said "oops, wrong house" and ran out. After the ordeal, we fixed the door and installed a new locking mechanism that made the door 10 times more secure out of our own expense. When they came back and we told them what happened, the wife was furious. She blamed the attempted burglary on our presence in her home.
Let's step back for a moment. If we hadn't been there, that burglar would have cleaned the house out. We tried to explain this to them that the attempted burglary had nothing to do with us being there and that we actually saved the place from possibly being vandalized. They wouldn't hear anything of it.
The point is I've noticed all my life that when an elderly has made up his/her mind about something, it requires an act of god to change his/her mind. It doesn't matter how logical your position is or how much evidence you have, they seem most reluctant to be swayed.
I also fully admit I don't have any number to back up my position. All I have are personal experiences with the elderly.