Before the advent of cities and civilization–a word which actually came from the Latin word for city–people lived in small settlements. Before that, they generally lived in roaming bands.
Such an existence sounds quite peaceful. Low population levels meant people had plenty of room to roam. There was enough for everyone.
Except that is not how it would have been at all. People roamed across large territories and scarcity could hit at any time. And you would never be truly safe because people are inherently dangerous to each other. Chimpanzees kill members of neighboring groups if they start encroaching on their territory. Human beings are certainly no less violent.
The desire for power and control also runs strong in human beings. Competition to lead even a small group can be quite intense, especially if decisions are literally a life and death matter. The more critical the situation, the more dangerous your opponents become. In times of plenty, disagreement is acceptable. In times of real crisis, disagreement can become a justification for murdering the leader or his allies.
I actually believe that the danger hominins posed to each other was a critical factor in the development of human intelligence. In my view, intelligence is similar to size and speed: animals become larger to compete with other animals, as a defense against predators, or as an advantage against prey.
The same is true of speed, of course. I once read about a deer or antelope species in North America that is extremely fast, faster than it ever needs to be, since no predators can even come close to catching it. Biologists speculated that there must have been an equally fast predator chasing the animal in the past. They finally found fossils of one and the mystery was solved.
I suspect that human intelligence must have also developed in response to some threat or danger. It has also seemed to me that that danger must have been other human beings (or rather, other hominins, since so much of the increase in brain size occurred before our species existed). What else besides people could pose a danger so complex that humans would need such a high level of intelligence to stay alive?
I am aware that evolutionary biologists speculate that it was the difficulty of living in harsh, rapidly changing conditions that drove the development of human intelligence, or that human intelligence developed simply because it could, when human predecessors started eating meat or, perhaps, tubers. I find these explanations unconvincing. The first seems too unique and unusual a response to conditions that affected thousands of species. The second explanation seems to say that a new physical characteristic developed simply because it could, rather than in response to a specific need. In my speculations, the reason human beings became so intelligent was so they could defend themselves from other human beings: they and their predecessors were engaged in an intellectual arms race with other members of their own species.
Perhaps I am giving the impression that I believe human beings are still this dangerous. I don’t. I think modern human beings are the result of a long taming process and that they have ceased to be as dangerous to each other as they once were.
I have read recently that ancient hunter-gatherers actually had larger brains than we do. The author of the article I read speculated that this was because human beings had to keep track of so much more information in order to stay alive: poisonous plants, dangerous animals, and other critical information they needed to stay alive in a world that continually challenged survival.
I googled this today and found that this decrease in brain size really did happen–our brains are about 10% smaller than the brains of people who lived 20,000 years ago. I also learned that some scientists do link it to the taming of the human race. The scientist quoted in the article I found today suggested that smaller brains create more tolerant people, since a smaller brain size is typical of domesticated animals. I speculate that the human brain might have shrunk because people are no longer so dangerous to each other. Rather than a smaller brain aiding domestication, I think it is likely that a larger brain simply becomes unnecessary in a safe environment.
I can’t say when the human taming process began, but I have now learned that the decrease in brain size happened after the big leap in human culture 30,000 years ago or more, which included signs possible religious rituals. Those cultural changes might have lessened the danger people posed to each other. Humans being what they are, any evolutionary pressure on them has two results: rapid cultural changes and slow genetic ones. We adapt our cultures to new challenges. Then if the new situation remains in place for enough generations, our genes adapt to it as well.
Cultural changes include new social rules, philosophies and religions. I believe they all are constantly evolving to ensure that human beings allow each other to survive. Please note that this idea does not rule out the possibility that there is a God who reveals helpful information to people when they ask or when they are ready for new truths, any more than evolution through random genetic mutations rules out the possibility that a God drove part of the process. After all, a mutation caused by God will not bear his signature.
The taming of the human being has seen some horrific breaks, but it has been going on for some time and it is likely to continue. As hard as it is to believe, people are less likely to die in war than they were only a few decades ago. It seems reasonable that this trend will continue. At least, pretty much everyone hopes it will, which is a very good sign in and of itself.