the idea that beauty is a proxy for reproductive fitness because it is a proxy for health eg. by revealing low mutational load and low parasite load etc. overlooks the fact that beauty is also a proxy for reproductive fitness purely because of runaway sexual selection, “people find this hot because people find this hot”
Somehow it never occurred to me that this is a two-sided optimization process.
I knew it used questionable proxies for fitness, but totally missed the part where optimizing “be attracted to fitness signifiers” points in a different direction from optimizing “possess attractive traits”.
You see this really strongly in many bird species. Peacocks with larger, prettier tails are generally more physically healthy birds. But the tail itself is nothing but a drawback – it gets in the way as they move, it attracts predators, and it literally has no practical benefit whatsoever. It’s only purpose for the male is to attract a mate.
as Greg Egan said, the optimal swimming eel would lack gonads.
On a long enough timeline, all beauty contests are Keynesian beauty contests.
dammit that’s too clever