I'll take the contrary position to Yarvin here. Measuring intelligence and athleticism are both good proxies for "spiritual worth" within a given group. This only fails totally when you mix groups that were selected for the traits in question - Goodhart's law. https://twitter.com/Indian_Bronson/status/1273580795794526210 …
The mechanism is that within a group all those traits cluster together - the group has all the smartest, best looking, most athletic people is recognized by everyone and looked up to. This is normal and natural hierarchy.