Thursday, October 13, 2005

Meet Pavlov

Reciprocal Altruism and Catholic Social Justice I have casually mentioned in these Darwin posts - and probably in others as well - that a study of Darwin, and of sociobiology in particular, was one of many things that prompted me to take religious ideas seriously and investigate them instead of taking the cues and admonitions of the beautiful people that there was nothing to be seen there, at least not in the Judeo Christian tradition. Puzzlement ensues when I say that because Darwin is commonly taught to have "proven" that evolution is and can only be unguided. Darwin is "proof" that morals have no anchor in the real world and that life is so bloody that it can have nothing to do with any Christian God. Leaving aside the question of "random" mutation, which I've had enough of for the time being, the idea that Darwinism can have nothing to do with acts of selflessness - what used to be called altruism or virtue - has been behind the times since the 1970's. That was when Robert Trivers and others began to find ways of modeling how selfless acts can be a benefit. It turns out that living in a community in which individuals look out for one another can enhance your chances of having offspring that survive. Here is a Guardian article on Trivers:
Kindliness became part of human nature, Trivers argued, because kind instincts were rewarded and this happened because our ancestors lived sufficiently long lives in small stable groups to keep track of who owed whom favours. The great originality of the theory is not that it says that we are under certain circumstances naturally benevolent. Plenty of people had made that observation before. What no one had seen was that this benevolence requires a very strong sense of fairness if it is to become an established instinct. Fairness, or justice, has its roots for Trivers in the determination to see that other people are not cheating us, and taking favours without giving anything in return. From abstract notions about the flow of genes he had come up with concrete and testable ideas about the ways our minds work; and it turned out to be demonstrably true that we find it much easier to solve logical puzzles if they are framed as if they are about cheating rather than an emotionally neutral subject, even though the two ways of putting the problem are logically equivalent. The paper on reciprocal altruism, written before he had even gained a doctorate, has been enormously influential. Robin Dunbar, the professor of behavioral ecology at Liverpool University, says Trivers played a fundamentally important role in the development of modern evolutionary studies of behaviour and ecology. His four key early papers spawned (and continue to spawn) research in the study of both animals and humans. The importance of his contribution is beyond question. The modern field of behavioral ecology (the name under which sociobiology now travels) would simply not have been the same had he not written these papers. Trivers' early work set the foundation for a biologically based system of ethics, in which a preference for some sorts of justice was part of our nature. Matt Ridley, whose book The Origins of Virtue is largely an expansion and restatement of Trivers's argument, says that when he was a student at Oxford, and got a postcard from Trivers asking for a reprint of one of his papers, "It was like getting a postcard from God"; and the whole line of popularizing Darwinian books from Richard Dawkins all the way down to Steven Pinker descends from Trivers's insights. There is a paradox here. Ridley, a former science editor of The Economist, takes the moral of Trivers's work to be distinctly Thatcherite, and in general the attacks on sociobiology, as well as the defences of it, have taken it to be a Right-wing construction, and a way to defend power and privilege by showing they are part of human nature. Even fairly left-wing Darwinists like Daniel Dennett tend to discover from their study of human nature that the perfect way for humans to live is that favoured by professors at good universities on the East Coast. But Trivers, one-time friend of the Black Panthers, loathes the Bush regime more than most forms of authority.
Trivers' work, and work it has inspired, is absolutely fascinating. I do recommend Ridley's book, which is based in part on it. Trivers also deserves a tip of the hat for doing good science. His ideas are testable (at least in model form) and he has not tried to use them to advance his own agenda (that I'm aware of). Richard Dawkins uses his expertise to stump for atheism all the time and Richard Lewontin has said something to the effect that "good science challenges social structures." Trivers himself might tend left but the results of his ideas, and of those working in his wake, are a challenge to both sides of the spectrum. In The Origin of Virtue, Ridley writes about a computerized version of the game theory problem known as the Prisoner's Dilemma and how a solution that came to be called Tit for Tat seemed to solve it:
'Tit for Tat' is a mechanism for generating cooperation between unrelated individuals. Babies take their mother's benefience for granted and not have to buy it with acts of kindness. Brothers and sisters do not need to reciprocate every kind act. But unrelated individuals are acutely aware of social debts. The principle condition required for 'Tit for Tat' to work is a stable, repetitive relationship. The more casual and opportunistic the encounters between individuals, the less likely it is that Tit for Tat will succeed in building cooperation. ... However, there is a dark side to 'Tit for Tat', as mention of the First World War reminds us. If two 'Tit for Tat' players meet each other and get off on the right foot, they cooperate indefinitely. But if one of them accidentally or unthinkingly defects, then a series of mutual recriminations begins from which there is no escape.
Later in the book, Ridley describes what happened when a Vienese mathematician named Karl Sigmund set up experiments to see if 'Tit for Tat' could be improved on. In the new environment set up by his student Martin Nowak:
it was not 'Tit for Tat' [that came out on top] but a very near relation called 'Generous'. 'Generous' occasionally forgives single mistakes. That is, about one third of the time it magnanimously overlooks a single defection. To forgive all defections - a strategy known as 'Tit for Two Tats' - is merely to invite exploitation. But to do so randomly with a probability of about a third is remarkably effective at breaking cycles of mutual recrimination while still remaining immune to exploitation by defectors. 'Generous' will spread at the expense of 'Tit for Tat' in a computer population of pure 'Tit for Tat' players that are making mistakes. So, ironically 'Tit for Tat' merely paves the way for a strategy nicer than itself... But neither is 'Generous' the [solution]. It is so generous that it allows even nicer, more naive strategies to spread. For example, the simple strategy 'Always cooperate' can thrive among 'Generous' players, though it does not actually defeat them... But 'Always Cooperate' is a fatally generous strategy and is easily invaded by 'Always Defect', the nastiest strategy of all. Among 'Generous' players, 'Always Defect' gets nowhere; but when some start playing 'Always Cooperate', it strikes. So, far from ending up with a happy world of reciprocity, 'Tit for Tat' ushers in 'Generous', which can usher in 'Always Cooperate', which can unleash perpetual defection... it is the sort of untidy decision game theorists dislike...
More experimentation does lead to a better solution, one that will win the game and then remain stable. Meet 'Pavlov':
'Pavlov' is rather like simplistic gambler. If he wins on red, he sticks to red next time; if he loses, he tries black next time... This principle - that you don't mend your behavior unless its broken - underlies a lot of everyday activities, including dog training and child rearing. 'Pavlov' is nice, like 'Tit for Tat', in that it establishes cooperation, reciprocating in that it tends to repay its partners in kind, and forgiving, like 'Generous', in that it punish mistakes but then returns to cooperating. Yet it has a vindictive streak that enables it to exploit naive competitors like 'Always Cooperate'. If it comes up against a sucker, it keeps on defecting. Thus it creates a cooperative world, but does not allow that world to decay into a too trusting Utopia where free riders can flourish. Yet Pavlov's weakness was well known... it is usually helpless in the face of 'Always Defect'. It keeps shifting to cooperation and getting the sucker's pay off. So 'Pavlov' cannot spread until 'Tit for Tat' has done it's job and cleared out the bad guys. [It was] discovered, however, that ... in a more realistic game.. where each strategy rolled a die to decide what to do next, something very different happened. 'Pavlov' quickly adjusted its probabilities to the point where its supremacy could not be challenged by 'Always Defect'. It was evolutionary stable.
It might, at first glance, seem like anything that exploits 'Always Cooperate' can't be a good thing from a Christian, altruist position, but a moment's reflection puts us right again. In a fallen world, 'Always Cooperate' is not a good thing. It fails to recognize the world as fallen and is in denial about the existence of Sin, allowing it to spread. Pavlov, on the other hand, is "wise as serpents and innocent as doves." Even more impressive, when conditions improve, Pavlov becomes a lion that can lie with lambs. Pavlov's success can be seen as an indictment of left wing utopian pacifism and also free market capitalism (which could be likened to "any defection you can get away with is a 'rational' defection"). The conditions that allow 'Pavlov' and 'Tit for Tat' to thrive (self organizing, stable, repetitive relationships), can be seen as the fruits of Burkean little platoons allowed to do their work of policing minute social relations and debts that no police force or government could ever replicate without incurring prohibitive costs and distorting the social fabric in such a way that 'Always defect' suddenly makes sense. I see two main axes of social thinking are skewered by these results. The first is that 'the solution' to social problems lies in either strict welfare-pacifism or strict rebributive justice. The first is a left wing solution and the second a right wing one. Overzealous or injudicious use of either is no solution at all. The other axis is whether rights should belong primarily to groups (governments, unions, U.N.) or individuals. Again, the first is a left wing solution and the second a right wing one. The group solution, like the pacifist solution, does not give enough consideration to inadvertently creating situations that make defecting seem to be the best choice. The atomized individual that right Liberalism leans towards seems to favour the strong, (who can only be strong for a short time!) but by weakening the social web it causes even them to work harder than they need to in order to fulfill the needs of a fully human life. The constant warfare and competition it favours makes life hellish. By showing that human relations are always under tension (to give or take), Triver's work suggests to me that a healthy, prosperous society needs to constantly balance those tensions and resist the temptation to let adherence to one or the other warp and distort it. In a nutshell, Catholic social teaching seems to me to have found, in general terms, a reasonable middle ground that might fill this role. Here are a few Catechism entries that seem relevant:
1880 A society is a group of persons bound together organically by a principle of unity that goes beyond each one of them. As an assembly that is at once visible and spiritual, a society endures through time: it gathers up the past and prepares for the future. By means of society, each man is established as an "heir" and receives certain "talents" that enrich his identity and whose fruits he must develop. He rightly owes loyalty to the communities of which he is part and respect to those in authority who have charge of the common good. 1882 Certain societies, such as the family and the state, correspond more directly to the nature of man; they are necessary to him. To promote the participation of the greatest number in the life of a society, the creation of voluntary associations and institutions must be encouraged "on both national and international levels, which relate to economic and social goals, to cultural and recreational activities, to sport, to various professions, and to political affairs." This "socialization" also expresses the natural tendency for human beings to associate with one another for the sake of attaining objectives that exceed individual capacities. It develops the qualities of the person, especially the sense of initiative and responsibility, and helps guarantee his rights 1883 Socialization also presents dangers. Excessive intervention by the state can threaten personal freedom and initiative. The teaching of the Church has elaborated the principle of subsidiarity, according to which "a community of a higher order should not interfere in the internal life of a community of a lower order, depriving the latter of its functions, but rather should support it in case of need and help to coordinate its activity with the activities of the rest of society, always with a view to the common good." 1884 God has not willed to reserve to himself all exercise of power. He entrusts to every creature the functions it is capable of performing, according to the capacities of its own nature. This mode of governance ought to be followed in social life. The way God acts in governing the world, which bears witness to such great regard for human freedom, should inspire the wisdom of those who govern human communities. They should behave as ministers of divine providence.
Finally, two questions that are probably bound to arise: 1) If selfless acts are done for selfish reasons, are they still selfless? That depends on how the term is defined. I would argue that they are because there is never any guarantee that a selfless act will be repaid. The person doing the giving always bears that risk. 2) If morals are evolved, doesn't that cut God out of the picture? Now he doesn't even need to be the source of morality? If God created the world ex nihilo, then he is still the ultimate source of everything, including metaphysics. In fact, you could view evolved altruistic tensions built into human societies as evidence of the world being a hospital for sinners. We have opportunities to be humble aplenty.

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