when you referred to facial symmetry being considered "beautiful", it reminded me of a PBS show I saw a few years ago which examined media models and western cultures perception of physical "beauty".
the show, quite rightly, stressed that this perception of physical "beauty" was continually perpetuated by the media and is subjective, associated with western culture.
Symmetry is supposedly easier on the eye, according to this PBS show I saw, but the eye is trained by the media to accept certain appearances as beautiful.
Your definitions os Pretty, Cute, and Hot are your definitions.... the words you used to describe these subjective traits come from your perception and what you consider pretty, cute or hot..... as you so rightly said.
I find it interesting that you think Pretty and Cute fade, but not Beauty.
you also said that "Hot" was a "rather new euphemism" but I've been called hot for many years... er, i mean, i've been calling guys hot for many years.... er, dammit... i mean, i've known that term for a long long time. '-)
at any rate, my take on it is the cliche... "beauty is in the eye of the beholder"
What you think is beautiful, another may not. What I find attractive, another may not.
I don't think it has anything to do with symmetry – nor do i think beauty or attractiveness or cuteness or prettiness or hotness (to coin a word) fades.... on the contrary... I think as people become more mature and more self confident, all of these attributes increase, rather than decrease.
Outward appearance is greatly effected by inward attitude –– To me, a self assured, self confident, person is much more beautiful than one who doesn't like his or herself very much. It also has to do with energy. Energy, to me, is sexy. Whatever is in the inside, shows on the outside....
Of course, it helps when they brush their teeth, too.