Appearance Variation is useful for detecting Cuckoldry

I've often wondered, if heritability really is as high as they say for important traits, why women don't take advantage of this to improve the genetics of their children more? There are obviously evolved behaviors towards this - i.e. "attraction" is how the desire for quality genetics is expressed in both sexes. But it's not really a systematic thing - it's more emotional or instinctual.

It seems like being able to make more conscious decisions about this (for both sexes) would have a huge possible benefit, given the existence of big differences in genetic contribution when those kind of choices are being made.

So why doesn't it happen more? Cuckoldry rates according to historical testing are low, just a few percent.

One obvious reason is that men try to prevent this from happening to them; one way to detect it is to notice visual differences in how children look.

If this is the main detection method, then we'd expect increased cuckoldry in more visually homogeneous populations. So from a genetic perspective, women have an incentive to increase homogeneity, to broaden the number of potential fathers they can choose from while being undetected, and men have the opposite incentive, to be more genetically visually distinctive to limit female choice.

Longer term, we should expect some women would eventually set up a system to take advantage of this by finding a way to greatly improve the genetic quality of their children directly, through conscious action. There has been some effort towards this with nobel prize winner sperm banks, and some high profile cases, but it isn't common at all. If heritability is true, this is a huge, fairly easy gain that's not being taken, which is suspicious. I would expect it to eventually be figured out and start happening. It'd be interesting to examine what kind of mental/cultural changes would be required to do this, and find out if they have started to change, or if there are any sub-cultures that have begun behaving this way.