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Study: Chimpanzees Have Evolved To Kill Each Other

sciencehabit writes A major new study of warfare in chimpanzees finds that lethal aggression can be evolutionarily beneficial in that species, rewarding the winners with food, mates, and the opportunity to pass along their genes. The findings run contrary to recent claims that chimps fight only if they are stressed by the impact of nearby human activity—and could help explain the origins of human conflict as well.

41 of 224 comments (clear)

  1. No surprise by msobkow · · Score: 3, Informative

    Most animals fight for mates. The only reason they don't kill each other is it's tougher for them to be lethal about it. But if a moose could head-butt another moose into oblivion to win a mate, I've no doubt it would do it.

    --
    I do not fail; I succeed at finding out what does not work.
    1. Re:No surprise by BlacKSacrificE · · Score: 2, Interesting

      Hell, if I could headbutt another human into oblivion for a mate, I would too. Here's the funny thing folks, humans are animals too! We have all the same urges and evolutionary pressures, we just lucked out enough to have a brain big enough to develop domestic violence, child abuse and random acts of aggression against strangers/the weak (a lot of which can be trace to evolutionary behaviours anyway) to fill the hole that our self abstinence from murder has left. I will be very interested to see how this data fees into human behavioural study.

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    2. Re:No surprise by readin · · Score: 5, Interesting

      You're right. In a one-on-one fight there is some sense in not killing your rival if he's willing to back down so that you don't have to expend extra energy trying to finish him off.

      But when the battle becomes group against group the advantage of mercy is less clear. An enemy left alive has more choices. Rather than accepting that he can't defeat you he may come back with larger numbers. He may jump up and hit you from behind as soon as you turn to battle one of his companions.

      In an environment of tribal warfare, it doesn't make sense to kill your local intra-tribal rival because he's likely to be your ally in the next inter-tribal battle.

      --
      I often don't like the choices people make, but I like the fact that people make choices. That's why I'm a conservative.
    3. Re:No surprise by readin · · Score: 3, Interesting

      "Hell, if I could headbutt another human into oblivion for a mate, I would too. Here's the funny thing folks, humans are animals too! We have all the same urges and evolutionary pressures,"

      As any male should know who went to high school. What do you think all that bullying was about? Guys were showing their dominance to win females. Those same urges were why it was so hard for the guys being picked on to just shrug it off or ignore it - how can a male shrug off being humiliated in front of potential mates?

      --
      I often don't like the choices people make, but I like the fact that people make choices. That's why I'm a conservative.
    4. Re:No surprise by radtea · · Score: 4, Interesting

      War as practised by humans and chimps is fundementally different, it is a coordinated social activity most animals simply don't comprehend let alone practice.

      Two words: "kin selection".

      Humans and chimps are social primates. We live in groups that are relatively close to us, genetically, although humans practice exogamy (mating outside their immediate kin group) a lot more aggressively than any of our cousins.

      So to say "fighting for mates is always one vs one" is to say "kin selection does not exist", which it manifestly does.

      War is mate competition carried out by other means. There is no other rational for it (war is always economically irrational, although this is not generally understood because it "just makes sense" to so many people that war is somehow a good idea.)

      No individual of any species ever under any circumstances kills another member of the same species for any reason other than mate competition, either for themselves or for close kin (this is not quite true, but it should be the starting point of any analysis of deadly interpersonal violence.) Killing has zero to do with hunting behaviour--both male and female bonobos hunt, and don't kill each other. Elk are vegetarian, and do kill each other. Only when reproduction is on the line does the risk of being killed in a potentially deadly fight make evolutionary sense, in humans as well as in other species.

      In humans, war creates all kinds of mating opportunities beyond the simple-minded "conquer the enemy and rape their women" scenario. In particular, it creates opportunities on the home front of all kinds, and that is a very fundamental part of its completely irrational appeal.

      --
      Blasphemy is a human right. Blasphemophobia kills.
    5. Re:No surprise by msobkow · · Score: 2

      To be fair, most animals don't allow multiple males to lead the herd/pack/whatever, so it's harder for them to form an attack troupe like humans or chimps do. Yes, there are exceptions, but when those packs encounter another pack it's just as vicious a battle. And they will gang up on a lone intruder as well.

      I don't think humans or chimps are as "special" as a lot of people would like to believe them to be. We're just tool-using animals at the root of it all.

      --
      I do not fail; I succeed at finding out what does not work.
    6. Re:No surprise by penguinoid · · Score: 5, Informative

      Fighting for mates is always one vs one, winner take all, and yes they are trying to kill their opponent.

      Not true. In many animals, fights are intentionally non-lethal. Much like a fistfight, when both have knives. But if one unsheathes their claws (or whatever real weapon), then the other will too and they both run the risk of being maimed or killed. This works because the non-lethal dominance competition correlates pretty well with what would happen if they were fighting for real.

      --
      Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
    7. Re: No surprise by Anonymous Coward · · Score: 5, Insightful

      There is no such thing as "right" or "wrong" in nature and no delusions of morality can change that.

    8. Re:No surprise by viperidaenz · · Score: 4, Insightful

      What about the bullying that goes on in single sex schools?

    9. Re:No surprise by robbiedo · · Score: 2

      As any male should know who went to high school. What do you think all that bullying was about?

      Homoerotic tendencies?

    10. Re:No surprise by Anonymous Coward · · Score: 5, Insightful

      Here's the funny thing folks, humans are animals too!

      As far as anyone can tell humans have a much greater ability to engage in complex planning: to make decisions based on sophisticated predictions of future consequences from an array of different actions. If you're hanging out with your friend in your living room and he has to go to the bathroom, most likely he'll make some initial assessments of his options, gather more information to increase the accuracy of his predictions: "Would you mind if I used your bathroom? Actually, better use the one off the master bedroom the one down the hall isn't flushing very well these days.", and then act on his predictions. On the other hand, if you have a horse over to hang out in your living room then pretty soon you'll be up to your ankles in horse manure.

      We have all the same urges and evolutionary pressures,...

      Except that with our complex planning it's actually easy to satisfy our evolutionary urges without needing to resort to violence. And we're also able to realize that evolution is a natural law like gravity. That having children in order to be evolutionarily successful is like throwing oneself down a flight of stairs in order to be gravitationally successful - that evolution isn't what should happen - it's what does happen.

      ...a brain big enough to develop ... violence ... to fill the hole that our self abstinence from murder has left.

      No. People engage in violence when they're not able to find any other way to satisfy their (evolutionary) needs. Typically, the people who engage in violence are the ones with the brains that are too "small" - which isn't to say that smart people are never backed into a corner where violence is the only option. But most people who use violence do so because they are unable to make good predictions about all the possible actions and consequences available to them.

    11. Re:No surprise by dreamchaser · · Score: 2

      Mate selection is just one reason. Controlling resources is another.

    12. Re:No surprise by DigiShaman · · Score: 2

      For males, it's about achieving Alpha dominance and hierarchy. For females it's a little more complicated, but the queen bee syndrome comes to mind.

      --
      Life is not for the lazy.
    13. Re: No surprise by PvtVoid · · Score: 3, Informative

      There is no such thing as "right" or "wrong" in nature and no delusions of morality can change that.

      Don't be silly. Traits such as altruism, empathy, and a sense of justice are also evolutionarily advantageous, and have just as much of a Darwinian origin as dominance and brute force.

    14. Re:No surprise by Kielistic · · Score: 2

      Controlling resources attracts mates.

    15. Re:No surprise by PPH · · Score: 2

      Alpha dominance and hierarchy

      Which turns out not to be a great mating strategy. Genetic testing of animal species that live in alpha male/harem social structures has shown that quite a few offspring are fathered by males hanging around the periphery of the group.

      Chimpanzees, bonobos and humans have reproductive strategies and social groupings that make the identification of female estrus and control over their mating at the critical time extremely difficult. So they develop kinship bonds. The children are most probably the offspring of the immediate social group, so all the males have a vested interest in raising them.

      For women, the queen bee syndrome is a bit stronger as a means of controlling food resources. Everyone knows who mothered a child is, so there is more motivation to monopolize a group of males as resource providers. But females can't use sex to hang on to a man while raising a child, so they share the entertainment duties, so to speak, to keep the tribe or pack together.

      --
      Have gnu, will travel.
    16. Re:No surprise by Wootery · · Score: 2

      I take your point, but: the real point here then is giving the appearance of being a high-quality mate. 'Pride' is just a high-level construct of the species, not a fundamental force affecting the success of the genes.

      One cannot meaningfully use 'pride' as an explanation, when we're discussing behaviour from an evolutionary perspective, any more than one can use love, generosity, angry, or envy: they're all just 'implementation details'.

      From an evolutionary perspective, we run from danger to maximise our effectiveness in effecting the propagation of our genes into future generations. To say we do it because we're scared would be a non-explanation.

  2. Recent claims by whom? by Swampash · · Score: 5, Insightful

    What a load of PC "humans are the only baddies in the world" bollocks.

    Chimpanzees have a well documented history of intra-group hierarchical violence, violence against females and extra-group murdering raids. This is nothing new. Anthropologists have known this stuff for decades.

    1. Re:Recent claims by whom? by Anonymous Coward · · Score: 5, Informative

      What a load of PC "humans are the only baddies in the world" bollocks.

      Chimpanzees have a well documented history of intra-group hierarchical violence, violence against females and extra-group murdering raids. This is nothing new. Anthropologists have known this stuff for decades.

      Dolphins too. Including infanticide of a rival's offspring. Raping of females, its a gang thing too as accomplices restrict the females ability to flee.

    2. Re:Recent claims by whom? by Tablizer · · Score: 5, Funny

      Jeez, what a bunch of animals!

    3. Re:Recent claims by whom? by slashmydots · · Score: 2

      And lions eat deer and invasive species commit genocide against native species. That's nature. All the hippies need to get over it and come back to reality.

    4. Re:Recent claims by whom? by Spy+Handler · · Score: 2, Informative

      What the tree huggers will find even more horrifying than chimp warfare is how lions kill baby lions.

      True story. When the alpha male of a lion pride is challenged by another male lion and loses, the new lion takes over the pride. This happens inevitably as the the former alpha lion ages. Now the new head lion will often KILL all the lion cubs in the pride. Not because he's hungry, but because he doesn't like the fact that the baby lions are not his.

    5. Re:Recent claims by whom? by TapeCutter · · Score: 4, Interesting

      Whom? - A suprising number of well educated people are still unwilling to give Jane Goodall's pioneering work the recognition it deserves. These same people tend to belive animals are little more than automata, some even refuse to belive chimps have a mind of their own.

      --
      And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
    6. Re: Recent claims by whom? by Anonymous Coward · · Score: 3, Insightful

      Or something worse. The decline in violence is due to factors like reduced rewards and likelihood of punishment. Remove those and humans go back to their nature. The hippies were deluded fools. Those of them who have not committed suicide out of depression are now unashamed capitalists.

    7. Re: Recent claims by whom? by Concerned+Onlooker · · Score: 2

      It sounds like you just made that up. What evidence do you base that on?

      The good side of humans is part of our nature as well, and according to the trend it is an increasing part of our nature. Did you even bother to look at the article I linked?

      --
      http://www.rootstrikers.org/
    8. Re:Recent claims by whom? by icecoldkilla · · Score: 2

      Lions too. When a new male takes over a pack, many times the cubs are killed. Sometimes by the male, sometimes by the females. If the last mate wasn't strong enough to stay in power, then his cubs are likely inferior as well.

      Not exactly. The new Male lion kills the previous one's cubs to ensure that the pride females comes to heat much quickly and he can distribute his genes before he becomes old and driven out by another new Male.

    9. Re:Recent claims by whom? by jalet · · Score: 3, Interesting

      This works exactly the same with cats. This happened to us one time and 4 out of 5 newborn kittens were killed by an adult male (we arrived before he could finish his job). Surely enough a few days later the female came to heat again and that bastard took his share of it...

      --
      Votez ecolo : Chiez dans l'urne !
    10. Re:Recent claims by whom? by Calydor · · Score: 3, Funny

      It's almost like lions and cats are both felines!

      --
      -=This sig has nothing to do with my comment. Move along now=-
    11. Re:Recent claims by whom? by gtall · · Score: 5, Funny

      Those kind of people have never been owned by a cat. A brain the size of walnut generates the capacity to play, sulking when ownee admonishes it, buttering up the ownee for treats, etc. And then there is the room and board issue, it turns out most cats have a degree in financial services.

    12. Re:Recent claims by whom? by gnupun · · Score: 2

      Not because he's hungry, but because he doesn't like the fact that the baby lions are not his.

      No, he does it so that in the future, when he's no longer strong, and the baby alphas are now alpha, like their papa, are going to do to him what he did to their father. It's simply eliminating (future) competitors so he and his descendants can rule for as long as possible.

      This was quite common when kings ruled around the world -- surprising similarity between kings and lions.

  3. Huh by Zanadou · · Score: 2

    Huh. So, they're more like humans than we first thought.

  4. Known for a long time by Anonymous Coward · · Score: 5, Informative

    You see this from the anti-hunting and lunatic PETA crowd. "Humans are the only species that kill for pleasure or kill for reasons other than survival". Bill Maher (PETA member) said it several times last season of his Real Time show. Yet everything from orca whales to monkeys to domestic cats kills for reasons other than day-to-day survival.

    They kill for fun, for the adrenaline rush, for sport, for territory, and sometimes simply out of instinct or curiosity. Cats leave trophies on their owners' back porches. They'll kill birds and mice and even bats and then leave the dead body for their owner to find. Killer whales just slaughter packs of seals for fun. Often times just killing them and not even eating them. Some animals are so naturally deadly like sharks that they cannot help killing something by simply "test" biting an animal to see if its good food. A shark bites a human but realizes the flesh is poor and there are too many bones, so it backs off for good, yet the human is dead because half his stomach and leg were chewed off entirely by the shark.

    1. Re: Known for a long time by perpenso · · Score: 2

      There speaks a Fox News fan!

      No, a "Real Time with Bill Maher" on HBO fan. Its a great show, the guests/debate often interesting, but fact filled when Bill is speaking -- not quite.

  5. "could help explain the origins of human conflict" by timeOday · · Score: 2, Insightful

    I would like to hear somebody explain logically why they think the behavior of other modern non-human species provides more insight into human behavior, than simply studying human behavior directly.

  6. Re:Not just Chimps and Humans by perpenso · · Score: 3, Interesting

    Wolves will kill members of other packs that trespass on their pack's hunting range. Within a pack killing is extremely rare. The fighting within a pack is dominance and discipline related, it will almost always stop short of serious injury or death.

  7. Chimps... George Bush... by bussdriver · · Score: 5, Interesting

    But seriously, primate research is worthwhile on it's own. You can't directly prove connections between us and them; but that is not unlike a huge amount of science which relies upon observation, statistics and expert judgement calls. When they act similar that can be a clue or merely a coincidence but it warrants further investigation. It's a technique that allows for faster probing of the problem space. BESIDES, if you think that observing chimps influences their behavior (as the "skeptics" denier fanatics always claim) just imagine trying to study humans! Humans are way more difficult to study without influencing their behavior thereby tainting the study.

    The biological connection is obvious; any "insights" they do in the research with a biological connection become useful even if at 1st they seem unjustified. The work can be applied in new ways later on if one proves there is no connection.

    As far as pure human nature study by primate research; well, that is based upon theories which may or may not be proven some day in the future. You have the classic old Feud work on "base desires" which think about the primitive instinctive aspects behind the manifestations; his work in this area is the basis for modern propaganda (WW1 and really big after the Nazis used it so well. Today, it controls most consumers.) Following that success, one could approach further from that perspective - making our relation to primates and their more primitive state ideal.

    Ultimately, I think most the work in the area ends up with the search for biological parallels between us. Say that HATE is really just a manifestation of FEAR; can you ever prove such a thing? nope. not in a hard science way; it's all subjective. But if you can study primates you might find more concrete proof with them on a biological level. A Turing machine is a lame computer nothing like your CPU but it's useful to prove things (the difference being that you can concretely prove the CPU is equivalent to the Turing machine and you can't with a chimp since they evolved differently even if they are nearly the same DNA.)

    As far as evolutionary pressures-- the best theory for human brains was we already made it to the top of the food chain being as primitive as chimps and what made the apes of the plains smart was that they had to war against each other for resources. Just like humans have always done; my tribe and me against you and your tribe. Given how we are the most evolved distance running animals on earth, territorial borders are meaningless. Your group isn't going to give up after running down a lion to exhaustion for 20miles simply because you ended out of your usual turf.

  8. Re:No wonder by Barsteward · · Score: 2

    They are all now in the NRA

    --
    "The hands that help are better far than lips that pray." - Robert Ingersoll (1833-1899)
  9. Re:Wake me when chimpanzees invent smelting by BlueStrat · · Score: 4, Insightful

    {Wake me when chimpanzees invent smelting} ... and cast weapons made of metal from molds that they manufactured themselves, just so they can kill more effectively.

    Hard to tell what point(s) you're attempting to make here.

    So, is killing efficiency your yardstick?

    I don't see how efficiency relates. Heck, there are species of marine life who eat the egg-clusters and hatchlings of their competitors, and that's upwards of tens of thousands or more.

    Or is it the use of tools to kill?

    Chimps and other apes will often pick up a branch to swing at another when they are angry/aggressive. Other examples of tool-use by apes is abundant. Google will supply you with examples.

    Seems in that regard the only difference is the level of sophistication of the tools/weapons related to the differing complex intellectual levels of the two species.

    No doubt if apes had a similar size brain and intellectual capability as humans, the technical level of their weapons would rise as well.

    Many people like to attribute some sort of "perfect moral innocence" to animals while humans are somehow forever separate from animals and that all human effects upon animals are "unnatural" and inherently bad and wrong. They also tend to decry human behaviors that have roots in our animal nature as somehow evil and unnatural.

    It's an emotional response motivated by compassion and I appreciate that. However, humans are just as natural on Earth as deer or whales. Everything will always effect everything else, and species will go extinct and new species arise as long as life exists.

    Since our self-awareness and intelligence and ability to control our environment allows us to avoid natural systems of regulation, we must consciously choose to find a balance between not causing undue harm to animals and nature while not placing undue limitations on the advancement of humanity towards moving outwards into space.

    Earth is not a perpetual-motion machine, and we need to leave the cradle. Humanity cannot afford to hunker down, slow progress, and ration out ever-dwindling resources. That's a recipe for extinction.

    Balance is the key.

    Balance will not be found at the extremes.

    Strat

    --
    Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.
  10. Re:Not just Chimps and Humans by Guy+From+V · · Score: 2

    IMHO wild canid (i.e. wolf) pack mentality and hierarchy is much more complex and nuanced than the primate model, I'd even go out o a limb and say it's probably much more "evolved". Wolves are highly social, even more so than most primates, and exhibit a mosaic of harder-to-describe interaction such as pity, shame, the ability to "agree yo disagree", vastly intricate verbal and nonverbal communication (moreso than most animals) - shown most obviously in the number of different howls ...and practiced deception plus forgiveness and atonement. I don't have a specific link or citing for what I'm saying but I have studied this subject for a few years on and off online and in print. Primate social interaction seems simplistic and lacking comparatively.

  11. Re:No wonder by Jason+Levine · · Score: 2

    No, they need to come up with a triggering mechanism for grizzly paws. After all, don't we have a second amendment right to armed bears?

    Granted, I might need to reread that section a bit.

    --
    My sci-fi novel, Ghost Thief, is now available from Amazon.com.
  12. Re:"could help explain the origins of human confli by Kielistic · · Score: 2

    Humans have a hard time being objective about themselves.