Sunday, November 14, 2010

Moral Evolution

Having dabbled last time in why some have difficulty with human evolution, I thought why not jump into the lake with both feet? Like Janet in Rocky Horror, "I've tasted blood/Now I want more." I'll have to make do without a chorus chanting, "More. More. More."

One of the defining characteristics of human beings is an inherent disposition to morality.

For my purposes I'm going to define morality as a set of principles that are intended to apply to human behavior. I want to differentiate morality from sentiment-- where one might do the right thing just because it makes us feel good. Moral codes are defined not by what feels good but by how we make hard decisions. A moral decision without cost is no moral decision at all.

What's interesting about human beings is how various we are. Even with that broad diversity there are some features that appear to be present in some for in all human societies: gender roles, rules regarding pair bonding, religion, parentage, music, morality and dogs. I think we can be on fairly safe ground that when we find a feature common to all groups of human beings we can define it as a part of our common biological heritage.

Note that I did not specify the nature of the different rules regarding pair bonding, etc. Just their presence.

Franz De Waal, one of my personal heroes, has spent a great deal of time finding common ground between humans and chimps. The first book of his I read, Chimpanzee Politics: Power and Sex among Apes, was a brilliant case study of the rise to power of an alpha male, his fall before a rival, the building of his supporting coalition and his return to power. If chimps are that close to us in one arena, why should they be so far from us elsewhere?

De Wall goes on to discuss the presence of empathy across the animal landscape. (See here.) But empathy and sentiment are not morality. While the underpinnings of morality, the recognition of fairness, the ability to sympathize, altruism, appear to be present in several disparate species (not all of them primates) other animals do not appear to codify these qualities into morality. Moral thinking requires being able to abstract from personal judgment to judgment for the group-- to go from "this is good or bad for me" to "this is good or bad for all of us". It's not at all clear that other animals have been able to make that jump.

Not to mention that humans often follow moral rules when there is no one present to observe. Morality works when nobody is around. As Emilio Lizardo said, "Character is what you are in the dark."

Darwin thought that a moral sense was inevitable given the right circumstances. He thought that any social animal "...would inevitably acquire a moral sense or conscience as soon as its intellectual powers had become as well developed... as in a man." While I think this is probably true as far as it goes, I think it doesn't recognize any role morality might have played in the animal developing those intellectual powers.

One of the interesting facets about evolution how it self-modifies over time. Humans developed upright posture long ago. But the act of beginning to develop our upright posture also had effects on our diet, our gait, our ability to run from predators, etc. These changes then also modified our bodies regarding our upright posture. A selection for one trait doesn't just work on that one trait. It works on the rest of the organism-- which has a knock on effect on that one trait. Everything is connected.

Human brains are difficult to figure out. Not only because they are so complex but because they are difficult to take apart. How a femur fits into a hip is fairly straightforward. Teasing apart the musculature that makes it work is somewhat more difficult but not terribly so. But when you open up the skull of a mammal you find some jiggly misshapen structures that appear to be made of a stiff gray good. When you cut it open you get more gray goo. It takes a fairly sophisticated technology just to be able to see all of the cells at all much less how they talk to one another. The technology is barely a hundred years old. (And is the discipline two of my heroes: Ramon y Cajal and Sir Charles Scott Sherrington.)

However, we know it took quite a while to transform monkey to man in terms of upright posture, hands, feet, shoulder and size of brain. It seems unreasonable to me to then suggest that the brain organization, which surely must be the basis for our moral sense, took any less time for an equally significant change. While we must recognize that our ancestors from a million years ago were not us, we must also recognize that they did become us, with all our foibles including our moral sense. It must have evolved, feeding back into the rest of our evolution, just as the growth of our thumbs, the reduction of the shoulder and the lengthening of our femur. And with all of the wrinkles, warts and discolorations that are the hallmark of the ad hoc nature of evolution.

So, given that assumption, we are pushed into the corner of an evolving moral sense that at worst was benign and at best aided our formation.

We are left, then, with wondering why we would have need of a moral sense and how it could possibly be selectively advantageous.

Most of the speculations I've read have to do with the invention of altruism, concern and action for the welfare of others that do not directly benefit the self.

Robert Axelrod wrote a book, The Evolution of Cooperation, suggesting that altruism came about in part as a mechanism to defeat the Prisoner's Dilemma. The game is boiled down to a situation where you and your partner execute a crime and your caught. The police grill you separately. Here's the deal. They don't have enough to convict you both outright but they have enough to send you both up for one year. However, if one of you turns on the other then they can free the defector and put the other one up for ten years. The best outcome for both is neither of you squeal and the two of you do your time. However, there is a significant advantage in defecting for the one to do it first. Remember, the two of you have been separated so it can't be discussed. If you're both "moral" (adhering to a code) and neither sticks it to the other guy, both of you have a better outcome together. But if you cheat you might get a better outcome alone.

To reframe it, you and your partner civil rights worker are caught in marching in Selma. Bull Conner takes you to jail and puts you in two cells so neither of you can communicate. Bull goes to each of you and says he wants a confession. First one who confesses gets out free and he'll beat the other one to death. And he'll keep beating on you until he gets tired. The rational, non-altruistic person gives in immediately, signs the confession and walks out of jail. The altruist takes a deep breath and hopes like hell there's a higher power that recognizes such sacrifice. There's no other possible gain.

How could such behavior possibly evolve?

Darwin invented the idea of group selection, where inherited traits are selected for and spread through a population such that the entire group of individuals benefits. There are some significant problems with this since it doesn't seem to account for the time between when the trait first appears and when it has saturated the group. The trait must not only benefit the individuals with the trait so it can spread, it must also benefit the individuals of the group without the trait so the group can be selected for. Some traits might work this way-- immunity to disease, for example. It benefits the individual that doesn't get sick and it also benefits the group in that the disease is deprived of a vector. It's hard, though, to see how altruism would work in this way.

Another idea is reciprocal altruism, the I-scratch-your-back-if-you-scratch-mine. This has some credence as evidenced in a variation of the Prisoner's Dilemma when the game is repeated. As the game proceed (or life) proceeds and the behavior and reliability of the other person is discovered, the partners can rely more on a verified prediction of their partner's behavior. One would also presume, as described above, that if you see your partner civil rights worker standing fast it would be more likely you will stand fast, too.

Computer simulations (and actual PD tournaments) have suggested that the best strategy for long term victory to be nice:
  • Cooperate: never be the first to defect
  • Return defection for defection, cooperation for cooperation
  • Be fair with your partner
  • Don't game the system
One wonders about the last point. I expect gaming the system works only so long as cheating detection and punishment are effective. "If we reward Wall Street, they will do it again" sort of thing.

But I think these altruistic approaches solve only half the problem. Yes, we do good things. It's good that the fig wasp doesn't lay so many eggs it kills the fig tree. It's good the cleaner wrasse isn't eaten by the shark it's cleaning. But while not all sharks are human beings, some human beings are sharks. We have to accept that the species that likes puppies and pats the heads of small children is the same species that tortures and eats those children and puts their parents into gas chambers.

Let's go back.

Humans likely lived early on in groups similar to that of chimpanzees. These are called fission-fusion groups. These sorts of groups range around 50 individuals and sleep together even if they range in small groups during the day. One could argue that humans live in elaborate fission-fusion groups today if one changes the word "sleep" to "work". But that's another blog entry. But we have a singular difference that happened very early on. We were essentially omnivorous scavenging prey species for a long time. Somewhere between Homo habilis and Homo erectus we became hunters.

Now, this is interesting. Band size was on the increase. We had meat-- brain food if ever there was one. We went in to being Homo erectus already social and fairly smart-- brain size was similar, though somewhat larger, than modern chimpanzees. By the time we were Homo erectus, brain size was 850 cc and rising. We started smart and we got smarter in about a million years. More interestingly, we went from being prey to being predators. But I suspect our brains, while bigger, weren't organized all that differently. After all, we had more or less the same body as before with some significant improvements. It's likely the brain was also more or less the same as before, with some significant improvements.

Let's think about that for a minute. You're a chimp out there in the veldt. You worry at night about leopards and hyenas. You worry in the daytime about lions and hyenas. You're always looking over your shoulder. Within the group you're always worried about your place in the group-- getting cast out means pretty close to certain death. Worry, worry, worry.

Then, in a blink of an eye, you're out there killing some of these guys. Maybe not leopards, hyenas and lions, but those animals that were pushing you away from the carcass you were eating yesterday? They're the carcass today and you're eating them. Your brain gets bigger. You can see lots more ways to do this killing thing better.

Back in the olden days, you were Long-Nose-McGrunt, not much smarter than a chimp. When Og-Hefty-Balls came down and beat the crap out of you because you were trying to get it on with his favorite female, Big Bumps, there wasn't much you could do.

Nowadays, you have a much bigger brain. You look at Og-Hefty-Balls over there and you think, Hm. You know, if I took this sharp bit of flint and sliced the tendons over his ankles he wouldn't be able to walk. Sure worked that way on the buck we killed last week. Probably work on him just as well. Then, Big Bumps would be available.

Or Big Bumps might be saying you know? Og-Hefty-Balls is okay as a hunter but he doesn't treat me so well. Long-Nose is always nice. I bet if I cozy up to Long-Nose over there he might just solve this problem for me. Or, I could just borrow a knife from Long-Nose and do it myself. What's to stop me?

That scenario wasn't so adaptive. They found the remains of that particular group all over the cliffs at Olduvai.

But the other group across the hill thought, well, I could slit Og-Hefty-Balls crotch to sternum and have my way with Big Bumps. I just don't want to.

They did all right.

Links of Interest:
Science of Morality
Moral Thinking from The Economist
Evolutionary Origin of Religion
Richard Joyce's The Evolution of Morality

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