The evolution of taste: biological or cultural?

I reproduce an interesting subject post in the IWC forum (which is open only to subscribers). Tanzer comments:

";As I get older, I find myself increasingly looking for freshness, clarity, complexity AND sweetness of flavor, and I find heavily new-oaky and high-alcohol wines more and more tiring.

On the other hand, I’ve had firsthand experience with some older English tasters (and I mean gents in their 70s or 80s) who told me that as they grew older they gravitated toward increasingly sweet wines (I’m speaking here of ripe fruit, as opposed to residual sugar). But I don’t know whether they were simply looking for wines that required less mental effort to appreciate or whether their taste buds literally changed over time.

Actually, I have a suspicion that the receptors on the tongue for bitter and sour tastes become more sensitive over time, and perhaps those for salty tastes as well. (I believe that Emile Peynaud pointed out that, of the four basic tastes, only the sweet taste is really agreeable.) As the sour taste comes from a wine’s acids, and the bitter taste from a wine’s tannins, it makes sense that as one grows older one would be less tolerant of acids and tannins, and gravitate more toward sweetness, which can mask the effect of sour and bitter tastes.";

(...) ";those who increasingly gravitate toward sweeter wines (which generally correspond to wines with higher alcohol) may be moving in the opposite direction. Based on at least this anecdotal evidence, it would thus seem unlikely that biological change is a determining factor.";

Are you aware of be evolving in one of these directions? A biological factor or an intellectual-cultural one?

Now I am looking more (specially at the table with food) for wines with delineation and clarity, which usually means leaner, but brighter and more vibrant wines (thanks to good acidity and a mineral quality). And, unfortunately, I think most of Spanish high-end wines gravitate now more on the fruit bomb side... lacking delineation and nuance.