I have always been clean shaven (and short-haired - even before it started to recede and thin) - a typical Roundhead Puritan in fact - and this description probably fits fairly well with my natural disposition.
But it has always seemed surprising that to be clean shaven has been the norm for the past several generations.
Surprising, too, that beards fall into two main categories: the patriarchal and the anti-patriarchal (or Leftist) beard: these seem to be perennials.
(I leave aside temporary fashions for sculpted facial hair - moustaches, goatees, long sideburns etc - I focus on the full beard in its natural more-or-less natural form.)
It is notable that the full beard is worn by patriarchs such as Orthodox Jews, Muslim clerics, Eastern Orthodox Priests, Amish (well, this shaggy rim-beard is a bit more of a tribal symbol) - the beard apparently signifies maleness and authority.
But a similar beard may be sported by beatnicks, hippies, feminist men, communistically-inclined scientists, health food shop owners and the like - where it signifies something near the opposite: gentleness, pacifism, abstraction?...
There are patriarchal religious exceptions. Roman Catholic priests, who are of course not strictly patriarchs, seem never to be bearded (maybe they are forbidden?) and nearly all Mormons seem clean shaven (Orson Scott Card has a goatee).
I accept that men are supposed to be bearded, and there is something a bit warped about the norm of being clean-shaven - it probably signifies some kind of narrow fanaticism (certainly it does in my case...).
But then why the anti-patriarchal beard?
Best guess is subversion. Look like a patriarch, behave like... something very different - hence destroying the power of the beard as masculine symbol.
Any better ideas?