Well, duh. No, I'm not going to oppose the conventional wisdom on this. In some sense, the answer has got to be "yes." But I've been thinking about David Mamet's turn, and an interesting little article in the the UK's Independent about famous right-faces (here you see William Wordsworth, grandaddy of them all), and I'm wondering what this phenomenon really amounts to.
I keep coming back to a little book by Thomas Sowell, A Conflict of Visions. Of all the things I 've ever read, it comes closest to making conservatism sound like an intellectually coherent position.
Sowell speaks of two different visions of human life: the unconstrained (or Utopian) and the constrained (which he calls the Tragic).
I would add that there are two elements of the constrained view: your world can be naturally constrained (Sowell's main concern) or it can be morally constrained.
The naturally constrained vision would go something like this: It might be nice if everyone could live in mutual love and caring, like one huge nuclear family, but human nature does not allow it. People really care about themselves and a very small group of family, friends, and colleagues (ie., they are "narrow," "selfish," "sinful"). Also, there are insurmountable practical problems (insufficient knowledge, coordination problems, etc.) involved in achieving the Giant Happy Family concept.
The morally constrained vision would be something like this: It might be nice to force people to serve the Giant Happy Family, but you would be violating their rights to do so. Without your leadership, people will devote their lives to narrow, petty pursuits, but they have a perfect right to do so. Their lives are theirs, not yours, to dispose of. Maybe you would spend their money on the Greater Good, and they will just spend it on themselves and their families, but that's tough. It's their money and you can't have it.
If your view is naturally constrained, you are a conservative (like Sowell). If it is morally constrained, you may be a libertarian. (Other morally constrained visions include pacifism and vegetarianism.)
Maybe what happens as you get older is you come to appreciate constraints more. You stumble over those natural constraints. You see Utopian dreams turn into Stalinist nightmares. You see moral constraints enabling hopelessly diverse people to get along peacefully. And maybe, as Mamet suggests, you also find that the constrained system really doesn't work out so badly after all.
Added later: I just found an article that describes a study that supposedly shows that people become more liberal, not more conservative, as they get older. You will find it here. Before you figure they must be right, notice that among the synonyms for "conservative" these people use is "rigid," "stuck in their ways of thinking" "not open to new information." They also seem to use racial prejudice as an index of conservatism. Wow. How many different things are wrong with that? Would you trust these guys to do a careful, unbiased study of ... anything?
Added still later: Jonah Goldberg has found more examples of this if-you-are-not-a-left-liberal-like-me-you-must-be-narrow-minded phenomenon. Given that this attitude, in itself, is a transparently obvious example of narrow-mindedness, I find it actually pretty funny. To paraphrase Saint Oscar, you'd have to have heart of stone not to laugh at it.