Steven Pinker -- How the Mind Works - Hampshire High Italian ...

Family Values 503the same time. Needs may change; if I help you now in return for protectionof my unborn child, I cannot collect until the child is born. And surplusesoften are staggered; if you and I have just felled antelopes, there's nopoint in trading identical carcasses. Only if you felled one today and I fellone in a month does it make sense to trade. Money is one solution, but it isa recent invention and could not have figured in our evolution.As we saw in Chapter 6, the problem with delayed exchanges, or reciprocation,is that it's possible to cheat, to accept a favor now and notreturn it later. Obviously everyone would be better off if no one cheated.But as long as the other guy might cheat (which is inevitable when individualscan vary), I may be discouraged from extending him a favor thatin the long run would help us both. The problem has been compressedinto a parable called the Prisoner's Dilemma. Partners in crime are heldin separate cells, and the prosecutor offers each one a deal. If you rat onyour partner and he stays mum, you go free and he gets ten years. If youboth stay mum, you both get six months. If you both rat, you both getfive years. The partners cannot communicate, and neither knows whatthe other will do. Each one thinks: If my partner rats and I stay mum, I'lldo ten years; if he rats and I rat, too, I'll do five years. If he stays mumand I stay mum, I'll do six months; if he stays mum and I rat, I'll go free.Regardless of what he does, then, I'm better off betraying him. Each iscompelled to turn in his partner, and they both serve five years—farworse than if each had trusted the other. But neither could take thechance because of the punishment he would incur if the other didn't.Social psychologists, mathematicians, economists, moral philosophers,and nuclear strategists have fretted over the paradox for decades. Thereis no solution.Real life, however, is not a Prisoner's Dilemma in one respect. Themythical prisoners are placed in their dilemma once. Real people faceeach other in dilemmas of cooperation again and again, and can rememberpast treacheries or good turns and play accordingly. They can feelsympathetic and extend good will, feel aggrieved and seek revenge, feelgrateful and return a favor, or feel remorseful and make amends. Recallthat Trivers proposed that the emotions making up the moral sense couldevolve when parties interacted repeatedly and could reward cooperationnow with cooperation later and punish defection now with defectionlater. Robert Axelrod and William Hamilton confirmed the conjecture ina round-robin computer tournament that pitted different strategies forplaying a repeated Prisoner's Dilemma game against each other. They