100 years without a pandemic has made us stupid. Itâ€™s made me stupid, anyway.
So many questions about human nature that puzzled me, I now see answered. Why are we so tribal? Why does language change so quickly? Why are we so xenophobic – so fearful of people who look different from us even slightly?
Answer: communicable diseases.
The Andaman IslandersÂ had the right idea. They may or may not have known the missionary attempting to evangelize them was full of contagions that could kill them; but they had instincts, and culture, that protected them from infection.
Doesnâ€™t it make sense, evolutionarily, that groups survived that shut out/fought off/killed outsiders? Doesnâ€™t it make sense that language would fracture rapidly, to make ingroups and outgroups develop quickly? The fracturing of humanity protects it from diseases. â€œCivilizationâ€ doesnâ€™t like that, but biology does. And our innate cultural instincts (like language) assisted us biologically.
Deadly communicable diseases are a part of life weâ€™ve been alienated from in the 20th and 21st centuries. Antibiotics especially have transformed the world, allowing human population to explode, and also permitting factory farming on a grotesque scale. We know that antibiotics have a limited life that is ending soon, and our current viral pandemic is just a tiny taste of whatâ€™s to come once bacterial diseases return in force. But for over 100 years, weâ€™ve merrily reproduced and exploited without the natural constraint of disease that was a former bedrock of biological reality.
Xenophobia is maladaptive for global civilization, but itâ€™s perfectly adapted for keeping tribal cells of humans hygienically sealed off from each other. â€œRacismâ€ is only a thing in Civilization, in which humans enslave each other for commerce and power. Without slavery and exploitation, thereâ€™s no racism, because thereâ€™s nothing pushing diverse groups of humans on top of each other. Thereâ€™s only â€œothers,â€ the in-group and the out-groups. The xenophobic aspects of human nature seem appalling in Civilization, but must have worked very well in prehistoric tribal life. Groups were no larger than 150 humans, and most much smaller than that, each with their own dialects, and similar physical traits.
Of course humans would mate outside the tribe, to prevent inbreeding, so curiosity about the â€œexoticâ€ is another adaptive trait. The exotic is SEXY. Sexy, exploitable, and sadly aiding and abetting racism when repurposed in Civilization. But my understanding is that tribes had very rigid protocols governing permeation through inter-tribal breeding. They were not cosmopolitan. From a biological standpoint, cosmopolitanism = death. But Civilization loves cosmopolitanism: diversity means more markets and an extension of power. Open borders are a boon for global capitalism, but tribal intermarriages were anything but that.