13.04.2023
first relevant thing is mutations - generally speaking, some (very few) mutations are positive for the individual, but vast majority (like 99%+) are negative, because if something already works there's thousands more ways to break it than to make it better. if some genes are a result of generations of evolution and you make a random change then the probability of ruining it is muuuch higher than the probability of making a new cool thing. yknow, like when you change a random symbol in code with a bug, the probability of accidentally fixing it is much lower than the probability of now having 2 bugs. humans have 1,4 to 3 harmful mutations that they parents didn't have per generation; these happened during production of gametes or very early in embryogenesis. which is generally speaking nothing cause we have 80k genes but eliminating these before they layer up is mostly what sexual reproduction is for, as when we have 2 copies of each gene with one being broken the other tends to still work and when we have a broken gene half of our offspring won't have it. we're wired to look for "the best genes" (best is relative but yeah) cause the goal is our offspring having less harmful mutations than populational average. second relevant thing - the rule of costly signalling. a game theory thing (originally from economics) which says the only way to prove that you have a lot is to invest a lot, i.e. buy a very costly engagement ring to prove you're rich or bet a lot of cash in poker to prove you have good cards. the more you can accept losing the more you must have
now to peacock tails. let's say female peacocks like colorful tails. why, just randomly their eyes have the preference for gaudy colorful things. the most colorful male bird will have the highest number of offspring, so the mothers who picked him will have colorful sons and daughters who like colorful things even more than the average female, they'll inherit both the father's tail and the mother's preference. it creates a feedback loop. that's something fisher has proven happens in evolution
but. as peacocks grow bigger, more colorful tails, the cost of having these tails also grows. why, tail needs a lot of nutrients to grow big and colorful (even if you have genes for it, if you're starving it won't grow to its full potential), so you have to be well fed to grow it. makes you visible - attracts predators, if you can't avoid them you'll die before procreating. if you have parasites or are sick the tail withers. the cost of keeping an attractive tail is absurdly high at this point
therefore, it starts playing the role of so called indicator of fitness. so that's an additional pressure, on top of the feedback loop - if you don't, on top of genes for gaudy tail, have genes that allow to actually grow the gaudy tail and keep it in good condition - genes for immunity, physical fitness etc - then you don't reproduce; if you barely have enough energy to survive you won't grow the gaudy tail, which is a giant waste. there clearly starts a corelation between gaudy tail and fitness otherwise. the more you have the more you can invest in that bullshit
so the more the tail grows and becomes more colorful, the more genes the peacocks develop that have to do with the gaudy tail directly or indirectly. right so: mutations. notice, the gaudy tail is complex. symmetrical. on something like that, one gene going wrong can ruin the patterns super easily and make it negatively stand out. so: you need few mutations in the genes responsible for the tail to have a complex, gaudy tail. statistically, you'll have about as many mutations in the tail as elsewhere, so that indicates your general "ratio. many genes for tail = big sample of your genotype
the book i'm reading essentially argues that the human brain, beyond being useful i.e. for spatial orientation, memorising faces and social hierarchy, gathering and hunting food and whatnot, grew much bigger and more complex than in other primates for the reason being the feedback loop of all these aspects of sexual selection worked for it to develop a ton of "useless" qualities like the ability to make art, creative intelligence, spirituality and so on.
humans have mutual choice between sexes (unlike peacocks), so the offspring of both sexes would inherit both an appreciation for art and ability to make it. the brain, at only 2% of body weight, consumes 15% of its oxygen, 40% of its blood sugar, and 25% of its energy. it's a giant "waste" of resources on things useless for survival - like art - that other primates easily survive and reproduce without. it's also incredibly complex, so every little thing going wrong takes away from its abilities. the human brain has about half of the human genes involved and up to 1/3 is speculated to work strictly in there, so it's a good sample
so essentially speaking, poetry is something your brain can do in order to prove your body in general has few mutations and that your other genes are good enough you have energy and other resources so you can sit on your ass and write poetry. as it's a trait evolved very decidedly in sexual selection, it does so in order to charm a potential mate.
additionally on the role of confidence as a selection factor.
if you're attractive - you know you're hot and a keeper, getting partners and social status comes easily to you, etc - then it makes you confident so
1. at least in theory, someone being confident is a subconscious indicator that they have something to be confident about / don't have reasons to be insecure as we know, tho, animals often try to cheat evolution, so humans grew the annoying trait of being confident with nothing to show for it - but confidence already evolvled to be an attractive trait in itself if confident individuals had enough to show in the past so it often works, and also
2. confidence indicates they have luck with sexual partners cause that's what makes you confident. and luck with sexual partners means you're attractive. and attractiveness is attractive
sounds like tautology but actually no. fisher's loop. if you pick the mate who's seen as attractive then chances are (well fashion changes, hence populational variety) that your children will also be seen as attractive in the same population, therefore you'll have many grandchildren. so being considered attractive even in isolation is a desirable trait in sexual selection... hence why people are more likely to be attracted to someone if someone else around is already into them.... and confidence is something that normally follows being seen as attractive
like a feedback loop yknow individual is confident -> others subconsciously assume they're seen as attractive -> that's an attractive trait so they become attracted to them -> other people see that many are attracted to them, also become attracted to them even if otherwise wouldn't, and etc
then there's another aspect: attractiveness is attractive cause your children are likely to also be seen as attractive but also cause being chosen by an attractive person (as in widely considered such) proves your own attractiveness. cause you beat the competition, and that makes you considered more attractive and can get you more partners + makes you more confident, which....et cetera