Morris Berman:

Even the anti-chic can be made chic. A Canadian magazine, Adbusters, became somewhat famous for ridiculing the need to be chic. It is now one of the chicest journals around–“underground chic,” as it were. If you are not aware of this publication, you are definitely out of it, and not as good as the people who are aware of it and read it on a regular basis. You are leading a diminished, unchic life.
This brings us to the causes of chic. If it really is as frivolous as it looks, why are we all doing it? Why does all of life finally boil down to high school? Alfred Adler, the psychoanalyst whose major concepts were “superiority complex” and “inferiority complex,” argued that the two were intimately related: the desire to be superior masked a deep sense of inferiority. If I care that much about being chic, it must be because I know, on some level, that I am terribly unchic. And this feeling of being inadequate, which dates from infancy, can finally never be overcome; which means that chicness is infinite: you can never be chic enough. Malraux was right: we never grow up.
I had just the other day mentioned a book by Joseph Heath and Andrew Potter that examined this topic in detail (even criticizing Adbusters as well). In a nutshell, their argument was that while we typically condemn profligate consumption as something the mindless sheeple do to try to be like everyone else, the driving engine of it is actually the urge to differentiate oneself from everyone else by having different, cooler stuff (which always has to be replaced as the bovine masses eventually lumber onto what was once your exclusive territory). But buying more stuff, whether it be off-brand tennis shoes from Walmart or anti-name-brand shoes from Adbusters, only reinforces the idea that our personalities are defined by the stuff we have (or lack), an idea that the neo/post/whatever/capitalist system we have is perfectly placed to exploit.
That said, I also think the image of the perfectly self-contained, self-aware, unflappable person is largely a myth. Perhaps a useful one to hold up and strive to emulate, but a myth nonetheless. We’re social creatures who mostly derive our pleasure from the earthiness of our social environment, not the thin air of life on an intellectual mountaintop. Not many of us are rugged enough to stand being completely out of step with our friends and peers; most of us would feel twinges of insecurity and self-doubt if we couldn’t find reassurance and agreement somewhere. The attempt to wean ourselves off of defining ourselves by our material possessions is difficult enough; that of trying to consistently value intellectual principle over social acceptance is almost certainly a pipe dream.