[ZenGum]

I think there *might* be an explanation in the following:

*disclaimer* human behaviour may be affected by genetic factors but it is very flexible and malleable, both by environmental/social factors and self-imposed decisions. It is very unlikely to be "hard wired", except maybe for the heartbeat, and maybe not even that. I'll use the term "programed to" but what I really mean is "born with a tendency to behave generally like this".*

It would make sense for male humans to be programed to want a nice, healthily padded female as a breeding partner. What Flint said.

But! ideally, she should also be just ending puberty. That way she will be a breeder/mother for many years and also probably isn't already breeding with someone else.

A female of the ideal breeding body shape will be somewhat lean at the end of puberty, but voluptuous in the right places. She will fill out as she lives.

So what males are programed to find attractive is that curvaceous youngish female who is still a little slender in places.

Yet, as time goes by, life and motherhood have their consequences, and she is still curvaceous, but no longer has the youthful sparkle, and the slenderness has long gone. Males lose interest (the shallow pigs).

I hazard the guess that this is the source of modern women's urge to look young and of just the right body shape. Society and especially business (beauty industry) run with this and it grows beyond all sense or reason. It has pushed beyond the natural ideal to an even younger, thinner appearance. Hence the current obsession with thinness.

*Important disclaimer* This is all written focusing only on humans as creatures with biological urges. We have become far more than that. We do things for reasons, not urges, we have culture and knowledge, our societies have developed rules of behaviour. Anyone who lives by the rule of "Indulge biological urges whenever they arise (aka penis does what penis wants)" is falling well below the standards of being a "person". It is this reasoned behaviour according to social conventions that makes someone a "person" and gives them greater rights and moral worth than,say, a cow. IMHO.

So, chaps, just because your genes make you want to go and chase buxom young college chicks, doesn't make it necessarily okay to do so. But there's no need to hate yourself for having the urge.