Humans can be exceptionally kind, compassionate, and cooperative. And they can also be cruel, competitive, and the nastiest SOBs it will ever be your misfortune to meet. Is this a paradox? I used to think so when I was (much) younger, and apparently some people still do. Richard Wrangham, a professor of Biological Anthropology at Harvard, attempts to explain it.
I’ll try to summarize his position here:
The seeming discontinuity in human nature is due to innate aggressive proclivities that evolved over time, not just in humans but in several species. Wrangham distinguishes two types. Reactive aggression is the spur of the moment, lose your temper type of anger, the kind that (after things calm down) we’d probably view as an overreaction to some minor provocation. Proactive aggression is the cold, intentional type, the kind of aggression that takes a bit of advance planning or at least some prior consideration—like deciding you want someone else’s banana and laying a trap for the previous owner in order to relieve him of it. As a subset of this, he identifies coalitionary proactive aggression, which simply means that a bunch of people (or apes or prehumans or whatever) get together, pick a victim, and subject it to a very bad and often final day. From this come wars.
Humans, he says, have self-domesticated by breeding out extreme reactive aggression while breeding in a capacity for proactive aggression. This wasn’t intentional, of course. There were no prehuman eugenicists or alien experimental biologists behind it, although the effect was not unlike when humans intentionally manage breeding in order to domestic animals. (There is some interesting stuff about domestication syndrome that I won’t go into here because it would take a while, and it’s sort of beside the main point, but it is why dogs are cuter and cuddlier than wolves.)
In any population there will be some individuals who are bigger and meaner than others. Depending on the species, the biggest and meanest of them will become the alpha male. (Not being sexists here, but it’s pretty certain that our early ancestors were.) This male scores high on the reactive aggression scale, responding, well, aggressively to others who he instinctively views as challengers and competitors. Also within that population, there will be individuals who are less volatile, less competitive. They have a capacity to cooperate and eventually some of them do. They decide that they don’t like the alpha male getting all the best fruits and females, so they get together to change the situation. The ability of these conspirators to cooperate and tromp on the alpha male signifies lower reactive aggression while, at the same time, demonstrates higher proactive aggression.
Over time, genes for reactive aggression are bred out, while genes that promote cooperative behavior, and hence proactive aggression, are favored. After several thousand generations, individuals with instinctive dispositions for nasty and brutish behaviors are reduced and those who possess a greater capacity for cooperative and scheming behaviors become the norm. This brings us to today and a species that usually gets along well with others but can, at times, excel in cruelty and sadism.
That’s the in-a-nutshell version of the author’s point, as I see it. I’m not sure I totally accept his argument or his definitions, and I’m quite sure that the subject of human competition and cooperation is far more complex than this, but it’s a good start at an explanation.
(I’m tempted to write more about this because it’s a fascinating subject, but I have bills to pay and other mundane things to do today.)