Hypothesis: Reason vs. Anger
I've been developing a hypothesis in the back of my head for some time now:
Evolution developed anger as a countermeasure to reason.
That anger and reason are forces in opposition is obvious to anyone with an IQ over 75. That's not what I'm talking about. What I'm trying to explain is how anger came to be. And with so much else in my recent research, it all comes back to tribalism.
We evolved from killer apes, and from killer apes we inherited a peculiar but very effective survival mechanism: the tribe. Tribes are an interesting piece of biological machinery. They're actually genetic amplifiers for what we now call "alpha males," and the idea is to select for the genes of the meanest badasses in the neighborhood, so to better compete with the badasses living on the other side of that hill over there.
While we were killer apes and primitive hominids, it worked very well. Evolution is always trying new things, however, and a few tens of thousands of years ago something new appeared: abstract thinking. On an individual level it was a big win. Hominids who could think their way through a sticky situation would leave more children than hominids who just followed their killer ape instincts. But on a group level, it tended to erode the much older tribal mechanism. Let me demonstrate what I mean with thirty seconds of drama:
[Foot Soldier:] Boss, out on the front lines, we've been thinking. Ten of our guys took a spear in the guts this week alone. The yukfoos have some newfangled spear-thrower thingie that works way better than bare hands. If we keep this up sooner or later we're going to run out of foot soldiers.
[Tribal Leader:] Nonsense, my friend! The yukfoos are pure evil! If we don't fight them to the last man they'll steal our women! They'll steal our food! They'll slit our throats! They'll destroy everything we stand for! Get out there and kill! Kill! KILL!
[Foot Soldier:] Yeah, I keep forgetting! Arooo! Ngrglar! [Runs off waving spear.]
[Tribal Leader:] Damn, that was close. [Turns.] Hey, Jeeves, run down to the village and drag me up a woman, willya? See if you can find one I haven't had in awhile. If her husband objects, just slit his throat. Oh, and if anybody down there has any meat, grab it while you're at it. Cut off a chunk for yourself if you want, but bring me as much as you can. Man, I haven't eaten for an hour and a half!
There's nothing worse than tribal foot soldiers who begin to think about their situation in the abstract. They might just quit the game, run off and start a new tribe somewhere else, or possibly sneak back with one of the yukfoos' spear-throwers and nail the tribal leader through an eye socket. This would bode poorly for the continuing success of the tribal mechanism. So the blind watchmaker tries lots of things, and what works is a way to amplify tribal loyalties and cloud the emerging rational mind. This new countermeasure is anger.
From my readings in ethology and anthropology, it seems like anger is a fairly recent tool in the kit compared to the tribal mechanism. Animals seem blase about killing, as do most of the newly contacted primitive tribes that Jared Diamond studied decades ago. It's very much a "nothing personal, Mac" kind of thing. What we call psychopaths may simply be throwbacks. They don't get angry. They don't even get worked up. When they feel so moved, they don't think about it. They just kill. The possibility that they themselves may die in the attempt doesn't seem to bother them.
Anger makes it possible to bypass abstract thinking in ordinary people and make them do stupid and damaging things, ideally directed against other tribes. It can be triggered by a number of things, sexual jealousy in particular. Still, nothing seems to rev it like the notion of Us vs. Them.
Killing members of other tribes is now illegal in the developed world, but tribal leaders still stoke the fires of tribal anger to keep their omegas outward-facing and loyal, and damaging opposing tribes whenever possible, through the ballot box if not through the eye sockets. The end result is that the tribal mechanism remains very much alive, and very much at work transferring wealth and sexual opportunity up the turtle pile to tribal leaders at the top. Why anybody plays the game is a puzzle, unless it really is genetic and those who do it really can't help it.
Note well that this is a hypothesis. I'm not a sociologist, psychologist, or anthropologist, and I have no idea how one proves such things. I'm guessing it can't be proven at all. But man, that's how it looks from my window.