but does it explain it away? If you want to design a steam engine, you need to do your design calculations in terms of the concept of pressure. Trajectories of molecules have way too much irrelevant detail. So macroscopic thermodynamic properties, such as pressure and temperature, have micro-foundations.

Uhmmm ... what? on what ever scale you are building a steam engine, you deal with the factors appropriate for it. "micro-foundations", whatever they might be, do not matter. Where ever they matter, deal with them there, right? (are you speaking of plasma? or smaller, like quantum level? Each of those levels are different, and plasma is plasma, so all the steam engine ideas go out the window). It seems like you found a non sequitur to distract you.

You really should not use the word Egregores when you mean culture, and I do think you mean culture. You may not want to deal in supernatural or the psychic but by using that word you are doing exactly that. Some who believe in the supernatural see such forces manipulating people into doing things they don't believe in because they don't believe, whether it is into lying because even if they think it is bad to lie they have to weigh it against keeping their bosses happy or getting away with something big, or into doing far worse things. If you don't believe in it, then reject the vocabulary of it. I assure you there is ample vocabulary for what you are talking about without it.

Have you studied any cultural anthropology? Within that field there are many sub-disciplines and many schools of thought applied to it, like "structuralism", "post-structuralism", "materialism", and so on. I prefer the materialism approach, grounding cultural factors in the day-to-day lives and material survival of the population.

I agree culture is complicated, but two things to bear in mind: they are individual cultures meant to pair a population to an environment which includes neighboring populations and neighboring cultures as well as the geography and technology they have. To many people see some idea in a culture as if it is on an a la carte menu and try to adopt the idea as if they can really use it in their culture. To me, that is the "bad" cultural appropriation, whereas a heavy metal band using Afro-Cuban rhythms (WELL!) is not (but using them badly or in a mismatched way should be punishable, but that's just my opinion).

I don't see your stance as controversial, I just think you have not really looked at the fields of study that already cover these ideas, and are pulling unrelated vocabulary into it because of that. Early humans leading lives dominated by tribal warfare is not exactly the case, only where populations grew and became competing populations or populations out of balance with their resources. In other places, further up your "evolution" of cultures, some populations in stable regions just engaged in child sacrifice to their gods to deal with it. Then some wars appear to have been started to stop that practice. Some think the Etruscan's (source word for Europe I believe, so hmmmm....) and Carthaginians both started as colonies of the Phoneticians who were attacked for that practice and wanted to just kill kids to their gods in peace. If you want egregores, there is where you should be looking, the supernatural.

You misunderstand those who go and fight in very ancient, prehistoric, times because you are overgeneralizing. For example, there are those, well me and others who I stole these ideas from, who see the "viking" age and their gods are reflecting a very real and material reality in far-northern Europe. Fact is that the viking age was a time of a massive population boom related to solar cycles and warming. Land owners and farmers were stable enough and they tended to worship Thor. The "father-god" was Tyr going far back. Look at all the cities with Tyr as a suffix. But, Odin was the god of adventure (to put it loosely. I do not want to type an essay in an essay) and of shamanism. Those young men who had no land of their own had to fight for their place. Tyr was a god of war, but also of self-sacrifice the way a father would for his children. Tyr has one hand which he allowed to be bitten off by a massive wolf as the others subdued it, he gave the hand as a sign of trust to distract it actually. But, that's Tyr. Odin was also a god of war, but of the glory of it and conquest, not of the defense of one's farm or home. So, different times and different people seeking different ends make different god, or raise up different ones. The young men who needed riches and wives and food needed to go and get the means to purchase it, or to immigrate (hello British Isles, then Normandy, and eventually Iceland) new lands. (The Immigrant Song is about that) The young men who needed to do that to survive, because over population in farmable Scandinavia forced them into it. They did not choose child sacrifice that I know of, but did sacrifice slaves and adults, but not on a scale that would deal with the problem. Those young men went raiding and either died or stayed or came home rich enough to buy food and shelter until they needed to go do it again. Dying in battle was an honor because coming back empty handed and defeated was almost as much of a death sentence, but generally (danes especially) never thought of dying for the sake of going into valhalla when they could retreat, regroup, and find an easier target. Heroism was always secondary to pragmatism.

The biological basis you look for is probably hungry mouths to feed, and you should not need egregores when material reality suffices. You need propaganda to get people to fight the way you have them fighting. The people atop those fighting forces who will never risk getting hurt, (so not Richard the Lion-hearted, Alexander the Great, etc. Different processes at work there, but overpopulation in specific local areats is at work there too) do believe in egregores or at least the supernatural even if they do not use such words. That's why they enforce rituals on their populations every where they can from schools to courts to political events. You can not believe in the supernatural and still study the use of egregores as the word is correctly defined because those who use them think they are real. But that is separate from culture. Most of what you talk about is culture.

Honestly Christianity, with it's stance that "Love" is the will for another's best well being without regard to the self and lust and sexual attraction is a disordering of love such that it wants from the other a kind of sexual devouring and satisfaction of a sexual appetite that at best is mutual satisfaction that should only be used for reproduction and not satisfying of urges. It's no different than to eat to survive not to be a glutton. It pulls the rug out from under your war ideas and your "tribal" war. Materialist approach to cultural anthropology explains your war, and Christianity attempts to deal with the drive towards those material problems without mass child sacrifice.

You can't really talk about surrendering agency without considering what is gained in return. Kids who repeat what teachers say unquestioningly give up agency to receive approval (ego-strokes in the transactional analysis approach to pysch). Plenty of adults do it for money or security. Whole generations of female sci-fi writers wrote of characters without agency because they grew up in a culture that forced women to give up agency for security (for food, for shelter, hopefully from violence) and be home-makers. You can kind of tell when someone is writing based on the characters they write. No egregores needed to understand tossing away agency in a deal with ... someone anyway.