It's how sexual selection works in general throughout the animal kingdom. You can teach yourself to behave otherwise, but you're hardwired to behave a certain way.

Humans exist within a fitness gradient and we naturally evaluate other humans according to how they fit within it.

I don't like it, but we're bloody animals.

You're assuming a gradient of only one dimension.

It's a multidimensional landscape, and although people can see it differently, consistent patterns arise within the population.

I wonder how much is genetic and how much is learned or conditioned.