The Self-Domestication of Humans
In an essay adapted from his forthcoming book, The Goodness Paradox: The Strange Relationship Between Virtue and Violence in Human Evolution, anthropologist Richard Wrangham says that before humans domesticated dogs, cows, and pigs, we domesticated ourselves.
No other mammal has the brainpower to organize capital punishment. When language became sufficiently sophisticated, our ancestors’ ability to conspire led not only to a more peaceful species but also to a new kind of hierarchy. No longer would human groups be ruled by the physical force of an individual. The emergence of capital punishment meant that henceforth, anyone aspiring to be an alpha couldn’t get away with just being a fighter. He had to be a politician, too.
The result of generations of such selective pressure is that human beings are best understood as an animal species that has been domesticated — like dogs, horses or chickens. Recent archaeological evidence suggests that humans became increasingly docile and less reactively aggressive around the time of becoming Homo sapiens, a process that started about 300,000 years ago.
Markers of domestication show up in the fossil records of domesticated animals and they are present in human fossils too:
Dr. Leach listed four characteristics of the bones of domesticated animals: They mainly have smaller bodies than their wild ancestors; their faces tend to be shorter and don’t project as far forward; the differences between males and females are less highly developed; and they tend to have smaller brain cavities (and thus brains). As it turns out, all of these changes appear in human fossils. Even our brain size fits the pattern: While the human brain grew steadily over the last two million years, that trajectory took a sudden turn about 30,000 years ago, when brains started to become smaller.
The essay is from the WSJ and might be paywalled…here’s an article from Big Think early last year that goes over some of the same material. I couldn’t find a definitive paper that Wrangham has written on the topic…feel free to browse through his published papers on Google Scholar.