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The primatologist Richard Wrangam once advanced the theory that tribe vs. tribe conspecific homicides - what he called coalitionary killing - are an evolved tra
by OgsyedIE 6mo ago
The primatologist Richard Wrangam once advanced the theory that tribe vs. tribe conspecific homicides - what he called coalitionary killing - are an evolved trait that was selected for in primates by some kind of pro-homicide selection pressures in the ancestral environment (where homicide reliably grants an advantage to the expected relative gene frequency of the perpetrator's genes).
I haven't kept up with biology for years and don't know what the current consensus on the topic is but it's interesting to consider if some environments naturally promote the unlucky inhabitants to harm each other.
- londons_explore 6mo agoIt seems obvious to me - it's the combination of two ideas: 1. When competing for resources, killing your neighbour frees up resources, which you can take. Most species of animal and even plants do this to some extent. 2. By collaborating in a group, you can achieve more than individuals acting alone. This is the idea behind teams, companies, countries, etc. Combine the two ideas, and you get war.
- Sharlin 6mo agoIt's definitely not obvious, given that many, many gregarious species may certainly have inter-group clashes and skirmishes at territory boundaries but no full-scale war. Animals in general avoid violence between conspecifics, for the obvious reason that it's rarely worth the risk of being hurt unless you're very sure you're going to win. Dying for your group is something you almost never see outside eusocial species. Never mind dying in your prime reproductive age!
- ozim 6mo agodying in your prime reproductive age! I guess dying because you think you’re going to impress’s a mate and stay alive is quite common.
- bryanrasmussen 6mo ago>I guess dying because you think you’re going to impress’s a mate and stay alive is quite common. based on my memory of readings in the matter I don't think so, most animal species "impress a mate" is either 1. do mating ritual better than others 2. actually directly compete with rival who has mate to win mate. In the second more rare scenario the actually directly compete with rival tends to be very ritualized, and thus when you lose you don't actually get significantly hurt. In the ritualized combat for mates some species have evolved to points in which accidents become a major problem, for example Stags locking antlers in combat for does. Obviously this is a scenario where you want to impress and stay alive but it doesn't work out, but it is relatively rare in the species that has evolved antlers to the point where it happens, and it is rare for species to have similar problems, generally the one who loses these competitions does not die, they just assume a lower status. So all that said the human tactic of Bob, hold my beer while I impress Cindy by riding this croc, is a pretty rare tactic for getting a mate.
- bawolff 6mo agoIn fairness, i dont think dying to impress a girl is particularly common among humans either.
- bryanrasmussen 6mo agothat's true, but among humans the "impressing a girl" pattern seems to be more open ended as to how you will do it, and thus you end up with croc-riding accidents at times.
- bryanrasmussen 6mo agoI was just thinking, perhaps all the fiction that has this as a plot point chooses it because of the man bites dog nature of the incident.
- esseph 6mo agoI really did some extremely dumb things in my twenties that I'm extremely lucky didn't kill me.
- rapidaneurism 6mo agoDon't think of it as individuals, but as individual genes. A group of 10 with the same genes, that can eliminate a group of 10 with different genes by losing one individual (because they were fighting to the death, while their opponents did not) is 9 copies up. An alternative view is that in groups with alphas that father most offspring, and status is based on the individual's ability to risk death. Genes in an individual of low status are already 'dead' so manufacturing instincts and hormonal responses that increase violence does not have a downside.
- Thiez 6mo agoThe extreme version of this would be insects like ants and certain types of bees, where the vast majority of individuals are biologically incapable of reproduction, and serve the one or few queens that are capable.
- Jensson 6mo ago> Animals in general avoid violence between conspecifics That seems to mostly just be true for oppressed species that doesn't already dominate. For example Orcas attack each other when they get into each other territory, as do ants. Humans dominate most land animals today so they probably lost most of that since humans already kill enough that killing each other is no longer a benefit for them.
- bluegatty 6mo agoYes, but war is worse for all parties generally. Lions murdering prey to eat is a stable equilibrium. Primates fighting each other is not. Murdering for acquisition of a resource is short term advantage. We are strongly, strongly evolutionary oriented away from 'murder' - it's the original sin. It's not something we even argue over. Murder = Bad. No disagreement across cultures. Murder = social cheating. No disagreement there either. Or put another way - the 'self' can gain advantage with murder, but the group and species probably will pay for it long term. I wonder if there are just things that species really have to learn over and over, particularly things like 'active deconfliction' etc..
- mothballed 6mo agoIt might also depend on mating dynamics. If females mostly prefer to all mate within the top few percent of males in a community, there might not be much to lose if some of the lower status males of them take their chances going on a war party to conquer/steal some females.
- actionfromafar 6mo agoI think that’s too narrow. You can also advance your genes by helping your sisters or other close relatives have offspring.
- mothballed 6mo agoSure but you can advance your genes even more by taking a woman for yourself. And if there are already enough other males to ensure the survival of the females and children then it might be worth some of the males going to war to get some females. At some point the marginal utility of warring is better for both the individual and the group than the marginal utility of yet another non-reproducing male hanging around "helping" out their kin while eating the resources.
- missedthecue 6mo agoThis is one theory for crime. You could think of crime as a high variance high risk strategy to improve mating status. You might then expect most criminals to be young men, and for the straight crime rate to be higher than the gay crime rate. And indeed both of these are true.
- the_af 6mo ago> When competing for resources, killing your neighbour frees up resources, which you can take I don't think it's that straightforward. War is usually extremely wasteful for all involved, even the victor. Plus it puts the whole group at risk, if it spirals out of control.
- culi 6mo agoYeah, mycorrhizal fungi, the gut microbiome, lichen, pet dogs, etc. Nature is completely brimming with examples of cooperation. It seems to me that more often than not, teaming up with organisms around you will unlock the ability to use more resources you would otherwise have access to. I would guess that this strategy is much more generative than attacking your neighbors and thereby risk your own security We could hardly eat a fraction of what we eat today if we hadn't teamed up with microbes.
- dontlikeyoueith 6mo ago> When competing for resources, killing your neighbour frees up resources, which you can take. Most species of animal and even plants do this to some extent. If anything, I'd say plants do it more. Everything in the garden is trying to kill everything else.
- adsweedler 6mo agoSometimes they do it in their own species, but much more commonly they do it across species. Eucalyptus will kill all but eucalyptus. Redwood trees will form networks and help each other; even an albino redwood tree (no chlorophyll https://education.nationalgeographic.org/resource/white-wonders/ https://education.nationalgeographic.org/resource/white-wond...) can survive. A plant that killed all offshoots of itself would not survive. But plants much more often make perfect genetic copies than animals do, so the selfish gene can explain this behavior
- JohnMakin 6mo agoorangutans deal with similar and are notorious for being peaceful
- londons_explore 6mo agoorangutans murder eachother too sometimes. Their hand grip is enough to crush another's skull, and occasionally they do so.
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- hetman 6mo agoExcept in this instance the conflict erupted after the population size was reduced due to disease so it's not entirely clear this was caused by the scarcity of resources. Nor is it clear what selective advantage mutually destructive wars would have assuming plenty of resources. The researchers posit group relational dynamics being the primary factor.
- adsweedler 6mo agoScarcity of resources … what if maybe the disease made less “resources” available to these chimpanzees?
- konschubert 6mo agoImportant to remember that we as humans no longer compete for resources. We have more than enough resources to go around for 10 billion people. The limiting factor is in intelligence and dexterity. In other words, we get richer when we are more.
- Thiez 6mo agoWe very much do compete for resources. People die of famine, thirst, exposure, and other lack-of-resources-related causes every day. That we could theoretically feed everyone doesn't matter when people compete for more than their fair share.
- konschubert 6mo agoThese are distribution problems. Usually intentional. There is enough food to feed everybody.
- prerok 6mo agoEmm, what? You are aware of all the wars going on right now?
- konschubert 6mo agoYes and? They are not about natural resources.
- Thiez 6mo agoLiterally about land, oil, rare earth minerals…
- konschubert 6mo agoYou can claim that and it's a comfortable thing to believe but that does not make it true. If you want to convince somebody who actually seeks truth, you have to make an argument how any country who has started a war recently has had a net economic profit.
- jvanderbot 6mo agoThere's a simple energy argument for both predation and war. It is energetically cheaper to take than to build. If you can take with low risk, there is no (energetic) reason to not do so. Collaboration is the exception. That collaboration is everywhere in many forms is a testament to the power of natural selection.
- sjducb 6mo agoNormally there are more than 2 actors, which changes the reward structure. X spends resources to kill Y. This benefits X because X doesn’t have to compete with Y anymore. However Z also gets the benefits because they don’t have to compete with Y either. In addition Z hasn’t spent any resources to eliminate Y so Z wins. The stable equilibrium is 100% strategy Z. Most animals will use violence in self defence, or when fighting over a specific resource. They don’t kill to remove competition. Chimps and humans are an exception to this. Likely it’s because the coalitional nature of human and chimp violence reduces the cost of inflicting the violence to near zero, and the costs are spread across the group, so it’s worth doing.
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- JumpCrisscross 6mo agoI’m trying to find the source, but I remember a primatologist claiming that humans and chimpanzees are the only two species that embark on genocide. Not being satisfied with simply defeating the enemy, but actively hunting them down to ensure they can’t harm you again. In other words, precluding retreat. (Which creates its own game-theoretical backlash: never retreat.)
- nradov 6mo agoEvidence is limited but orcas might also do that to great white sharks. The orcas seem to sometimes work together to exterminate sharks from an area in a way that goes beyond just hunting them for food.
- JumpCrisscross 6mo agoI think the difference is extermination from an area versus exterminating a line. Humans and chimpanzees will exceed their territory to eradicate foes. That, per this primatologist, is a unique adaptation.
- dlcarrier 6mo agoKilling off another species isn't that much like genocide, which involves killing off a rival genetic line of the same species, but orcas do that too: https://pubmed.ncbi.nlm.nih.gov/29559642/ https://pubmed.ncbi.nlm.nih.gov/29559642/
- throwaway290 6mo agoI don't think this falls under definition of genocide > we suggest that infanticide is a sexually selected behaviour in killer whales that could provide subsequent mating opportunities for the infanticidal male and thereby provide inclusive fitness benefits for his mother. I can see gene fitness benefit but mating opportunities, how? "hey, me and maman uh killed your baby, wanna pump out a replacement real quick?"
- Shitty-kitty 6mo ago
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- everdrive 6mo agoBack in the old days people were much more unabashed about such things. What's the purpose of your very small collection of city states? Obviously to expand, and smash any neighboring states. If you succeed, kill all the men and take their women as slaves. This was much of civilization for a long time.
- Epa095 6mo agoTja, IAMNAH, but my impression is that there is much more diversity to history than that. Not all groups attempted to expand, and among those who did there are many who swallowed up close by groups without violence (rather through 'cultural victory' so to say). It might even be the norm historically.
- rcbdev 6mo agoWhat is a "Tja, IMANAH"?
- mike_hearn 6mo agoMy guess: Tja - German for "well". IMANAH - I am not a historian.
- Epa095 6mo agoYeah, you got it! After 30 years on the internet I should know by now whats understandable for others and what's not (I honestly just realized that English speakers don't say 'tja'), but alas.
- lamasery 6mo agoWe have a sound we usually spell “yeah”, which can also be an informal “yes” but can also server roughly the role of a “Well, “. The same spelling is sometimes employed for a cheer that might otherwise be spelled “yay” and sounds very different, though. I can think of at least one regionalism or dialect that has something that I bet sounds similar to yours, that might even be used the same way yours is: “valley girl”. The real tell was the spelling. We don’t usually use “T” to harden a phoneme at the start of a word—we do later, though, as in “itch”—and we don’t use “J” that way. “Ch” is probably the closest we’ve got to what you were going for with “j”. If a native English speaker were trying to reproduce the sound you’re going for in text, they’d not have spelled it that way unless trying to make it appear foreign.
- Culonavirus 6mo ago> primatologist sometimes I feel like that at work
- xg15 6mo agoGiven how easily we can separate people into "ingroups" and "outgroups" and always fall into the same behavioral patterns regarding them, even if the actual markers for the ingroups and outgroups are completely arbitrary, it really seems likely this is biological and not just cultural.
- trollbridge 6mo agoDon't ant colonies also go to war? I've seen that happen before and it's quite interesting - I read a theory somewhere that part of the purpose of this was to prevent overpopulation, so in the long run _both_ ant colonies do better since they don't "cooperate" and end up overpopulating.
- Xiaoher-C 6mo agoWorth adding some nuance to the Wrangham framing here — he's not wrong exactly, but de Waal spent decades documenting the flip side: chimps reconcile, console each other, maintain coalitions in ways that don't fit the "demonic males" narrative cleanly. Both are true, and which one you see probably depends a lot on which population you're studying and under what conditions. Ngogo (which I think this is) is in a fragment under real agricultural pressure. I'd be cautious about drawing evolutionary-psychology conclusions from a group that may be responding to a dramatically compressed territory rather than some baseline ancestral program. Same chimps in intact forest might look quite different.
- griffzhowl 6mo agoGood points, but it any case, it's true that chimps in general treat group members very differently to outsiders isn't it? Those behaviours that de Waal mentions seem probably directed towards group members. Are there any documented chimp populations where chimps aren't violently aggressive towards members of other groups? I remember reading, not sure if it's from de Waal, about chimp "raiding parties", where groups of young males will get excited and loudly vocalise as they gather together and head towards a neighboring territory, but when they get close they all go very silent, and will attack individuals from a neighboring troop if they sufficiently outnumber them. They tend to target the face and genitals when attacking other chimps, a different behaviour to when they're hunting monkeys, for example. I think Wrangham mentions that some chimps will hold the targeted individuals' limbs while others attack. Aside from the brutality, these behaviours seem too cogently goal-directed and sophisticated to just be responses to environmental pressures. There's some deeper reasons involved, imo, even if the severity of the violence is exacerbated by resource and territorial pressures.
- dumah 6mo agoHow are resource and territorial pressures not environmental pressures?
- griffzhowl 6mo agoThey are. I just used different words to refer to the same idea
- kjkjadksj 6mo agoFor whatever reason, bonobos living under similar environmental constraints don’t do this. This suggests to me that the behavior is strongly controlled by genetics. Makes one wonder about the warmongers in our own species if they harbor some warmonger gene.
- Andrex 6mo agoI mean, kill everyone else and you can be sure your genes are the only one propagating. Makes sense to me. However there must have been some opposite instinct that prevented monkeys from just wiping themselves out. I hope so, for our sake.
- dboreham 6mo ago> an evolved trait This is obviously not correct. There's no way to encode "you must hate and kill the tribe next door" into DNA. Clearly this behavior is emergent in the population. Perhaps what's an evolved trait is "have neurons with some mixture of properties, and response to hormones that tends to produce angry homicidal assholes in the presence of competition for resources".