Sometimes in an argument, an older opponent might claim that perhaps as I grow older, my opinions will change, or that I'll come around on the topic. Implicit in this claim is the assumption that age or quantity of experience is a proxy for legitimate authority. In and of itself, such "life experience" is necessary for an informed rational worldview, but it is not sufficient.
The claim that more "life experience" will completely reverse an opinion indicates that the person making such a claim believes that opinions from others are based primarily on accumulating anecdotes, perhaps derived from extensive availability bias. It actually is a pretty decent assumption that other people aren't Bayesian, because for the most part, they aren't. Many can confirm this, including Haidt, Kahneman, and Tversky.
When an opponent appeals to more "life experience," it's a last resort, and it's a conversation halter. This tactic is used when an opponent is cornered. The claim is nearly an outright acknowledgment of moving to exit the realm of rational debate. Why stick to rational discourse when you can shift to trading anecdotes? It levels the playing field, because anecdotes, while Bayesian evidence, are easily abused, especially for complex moral, social, and political claims. As rhetoric, this is frustratingly effective, but it's logically rude.
Although it might be rude and rhetorically weak, it would be authoritatively appropriate for a Bayesian to be condescending to a non-Bayesian in an argument. Conversely, it can be downright maddening for a non-Bayesian to be condescending to a Bayesian, because the non-Bayesian lacks the epistemological authority to warrant such condescension. E.T. Jaynes wrote in Probability Theory about the arrogance of the uninformed, "The semiliterate on the next bar stool will tell you with absolute, arrogant assurance just how to solve the world's problems; while the scholar who has spent a lifetime studying their causes is not at all sure how to do this."
I am not sure what to make of this, because I do think that many times the "When you get to be my age..." argument is often used to shut down an opponent. But... I also think that at times it has merit.
For instance, I don't know of a single one of the fellow art students who could understand the argument for needing to do 500 tracings a week when the instructor told us "At the end of the semester, you will understand why you needed to do them. At least, those of you who do them will understand why"
And, he was right, yet most of us were angry that he could have communicated this more effectively had he tried. However, if he had done a better job of telling us why we needed to do 500 tracings a week, it is likely that fewer of us would have done the 500 tracings a week (also supported by past evidence of when he used to give a fuller explanation to his classes. We could see in both the grades and the classes' work that they had not put in their time)... So, in that case, there was a motivational factor to have us gain the experience on our own, instead of trying to gain it through proxy.
BTW, the reason that we did 500 tracings a week was much like the whole Karate Kid "Wax On", "Wax Off" thing... So that our bodies would learn the motions of drawing, leaving our brains free to think about composition or morphology of the image on which we were working. Except that it was long before the movie ever came out.
I would love to get some examples on how "life experience" in general is necessary for an informed and rational opinion on a subject. The examples in these comments seem to relate to not "life experience" but specific experience (i.e. doing tracings, playing chess, etc.) Yet people seem to think that "life experience" in general adds "something" and that further conversation on the subject cannot substitute for it.
As someone whose peer group is generally much older than me, I can say from comparing myself to others t... (read more)