Under crowded conditions the friendly social interactions between members of a group become reduced, and the destructive and aggressive patterns show a marked rise in frequency and intensity.
We never stop investigating. We are never satisfied that we know enough to get by. Every question we answer leads on to another question. This has become the greatest survival trick of our species.
...In little more than a single century from 1820 to 19450, no less than fifty-nine million human animals were killed in inter-group clashes of one sort or another.... We describe these killings as men behaving "like animals," but if we could find a wild animal that showed signs of acting this way, it would be more precise to describe it as behaving like men.
The idea that it is funny to see wild animals coerced into acting like clumsy humans, or thrilling to see powerful beasts reduced to cringing cowards by a whip-cracking trainer, is primitive and medieval. It stems from the old idea that we are superior to other species and have the right to hold dominion over them.