Yes, indeed. A couple of years ago, I had occasion to go back through a large set of pictures taken in the mid-sixties, for a fortieth reunion of my high school class. Mostly just snapshots, but also pictures made for the school newspaper, yearbook, and some promotions sponsored by the local city paper. It was amazing just how attractive the average student was in those pictures, and how generally unaffected the postures and demeanors were.
My guess is that folks nowadays are too heavily influenced by the mass media; a large proportion of them seem to regard their self-images in relation to the extent that they either do or do not resemble one or another celebrity.
Another factor is perhaps that "just normal activities" aren't photographed as much any more; every picture is assumed to be some sort of portrait (hence the posing) and "if you own a camera, you are a photographer" so there is an obligation on the part of the subject to "perform".
Too bad, really; when all of the unstable color snapshots from the seventies have faded into oblivion, and most of the digital pictures have been lost to obsolete media, our grandchildren will probably assume that life today was exactly like it is shown in television, the movies, and glossy magazines.
(And yes, at forty-odd years out of high school, I'm a bit older than 32!)