This is ONE OF 4 responses to VC 17 John 9 ("Living in ruts")...
Hopefully I can bring that 95% agreement rate up a little higher by clarifying what I meant when I started discussing the lack of personality change after the the age of 20 for MOST people because of a lack of stimuli.
Perhaps I wasn't clear enough - but when I said stimuli I meant variety of stimuli. I go back to the small town in which I grew up, and the people that I went to high school with who have remained in that small town are still very much the same people, while those from my high school class who had gone on to college or travelled extensively, have definitely changed from who they were in high school.
I attribute this to the fact that those people who have lived in this small town all their lives are surrounded by the same stimuli all the time. They may have been exposed to the same quantity of stimuli throughout their lives as those people who have gone out in to the world (so to speak) but the variety of stimuli is very much constrained. I believe that this constant exposure to the same stimuli all the time is what puts people into a personality rut.
[Editor's note: For my response, see VC 18 John 13.]