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Do humans kill each other because it’s in our blood or is it all based on our environment? Philosophers and scientists have batted around theories for centuries. But an extensive climb through the evolutionary tree of mammals brought scientists to a fresh vantage point. From there, the answer seems to be: a mix of both, but mostly, it’s our blood.
After carefully compiling more than 4 million murder records across 1,024 mammalian species, evolutionary biologists at the University of Granada found that humans are more vicious than most mammals, but, generally, on par with our primate lineage. And this jibes with the rest of evolutionary tree, in which species tended to bunch as either murderous, slightly savage, or peaceful. Being territorial and social were big determinants of those bloodthirsty bunches, the authors note. Overall, the finding, published this week in Nature, offers solid support for the argument that homicidal urges stem from evolutionary roots.
However, when the researchers tracked the murder rates of human populations from 50,000 BC forward—capturing hunter-gatherers to bands, tribes, chiefdoms, and states—they noted that murder rates jumped around a lot. And the time-spans for those fluctuations in ferociousness are too swift for a genetic explanation. Societies, it seems, can modify our killer instincts.
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Source: Ars Technica – Controversial study pins humans’ murderous ways on our primate ancestors