中老年妇女交友群号:合作的进化：成还是不成？

在在面临着无数舞弊的诱惑时，人类是怎样合作的？这是心理学以及经济学研究的一个重要领域。很多这方面的研究都集中于合作时“一报还一报”的理论：也就是说，当与他人一起做事的时候，人类一开始都倾向于很慷慨，直到合作者并没有以德报德时候，人们就不会再那么慷慨。此时，彼此间的合作就不存在了。换句话说，被骗一次，是别人不好，被骗第二次，就是你自己的问题。

When he encounters such a withdrawal of collaboration, the theory goes, the malefactor will learn the error of his ways and become a more co-operative individual. And there is experimental evidence, based on specially designed games, that tit-for-tat does work for pairs of people. Human societies, though, are more complex than mere dyads. And until recently, it has been difficult to model that complexity in the laboratory. But a paper published this week in the Proceedings of the National Academy of Sciences by Nicholas Christakis and his colleagues at Harvard has changed that. Dr Christakis arranged for a collaboration-testing game to be played over the web, with many participants. As a result, he and his team have gained a more sophisticated insight into the way co-operation develops.

理论推测，当这个坏人碰到这种别人不愿意与之合作的情况时，他会从中吸取教训并且变成一个更合作的人。而且，基于特殊设计的游戏也给了我们实验证据，证明“一报还一报”适用于两个人之间。尽管人类社会比一对一的关系要复杂得多。而且直到最近，要想在实验室建立起这种复杂度的模型还是很困难的。但是本周《Proceedings of the National Academy of Sciences 》出版了一篇论文改变了这种情况。这篇论文的作者是哈佛大学的Nicholas Christakis及同事。 Christakis博士安排了一个合作性测试的游戏，这个游戏是在网络上进行的，参与人数众多。结果，他及他的小组得到了关于合作是怎么发展的更为复杂的认识。

Dr Christakis used what is known as a public-goods game for his experiment. At the beginning of such a game, points are doled out to each participant. During every round, players are given the opportunity to donate points to their neighbours. Points so donated are augmented by an equal number from the masters of the game. If everyone co-operates, then, everyone ends up richer. A “defector” who refuses to donate to his co-operating neighbours will, however, benefit at the expense of those neighbours. At the game’s end, the points are converted into real money, to ensure that proper incentives are in place.

Dr Christakis 在他的试验中使用了一种被称作公用品的游戏。在游戏之初，每个参与者都得到一些分数。在每一轮游戏里，参与者都有机会将分数赠送给他们的邻居。游戏的控制者会将这些被捐赠出来的分数加以相同的倍数。如果每个人都合作的话，那么每个人最后的分数都会更多。但是，不愿意将分数送给别人的“叛徒”只会得到他们从邻居那骗来的分数。 在游戏结束时，分数将会转化成真实的金钱，以确保有合适的激励措施。

To play his large-scale public-goods game, Dr Christakis recruited 785 volunteers via Mechanical Turk—a service provided by Amazon, an online retailer, that works by farming out small tasks to an army of individual workers. Each volunteer was randomly assigned links to, on average, eight other players. Together, they played repeated rounds of one of three variations of the game.

为了做这样一个大规模的公共品游戏，Christakis博士通过Mechanical Turk招募了785位志愿者。Mechanical Turk是由在线零售商亚马逊公司提供的一项服务，能够用来将小人物分发给一组独立的工人。 每个志愿者被随机平均分配了8个队友。他们在一起重复进行三个版本的游戏，每个版本分别进行多轮。

In the first, participants always interacted with the same group of people. In the second, the connections were randomly reshuffled after each round. In the final version, one-third of the possible pairings between participants were chosen at random after each round (such pairs may or may not, therefore, have been dealing with each other in the previous round). One player from each pair was first told or reminded of how the other had behaved in the previous round, and was then asked whether he wanted to break his connection with that player, if he already had one, or form a new connection, if he had not.

在第一版本中，参与者总是会与同一组组员一起互动。第二个版本中，组员之间的关系在每一轮之后被随机重组。在最后的版本中，三分之一的参与者之间的可能配对都在每一轮之后被随机选出。（因此，这样的配对，有可能也不一定会与在上一轮游戏中打交道的人碰面。）在每一小组中，组员都会想起或被告知他的对手在前一轮的行为，然后，如果他们之前已经合作过了，就会被问到是否不想与对手合作，如果没有合作过，是否愿意和对手合作。

In all versions of the game, roughly 60% of players started out co-operating. However, in the first two, this decreased over time as the pernicious influence of the freeloaders spread. The larger the fraction of a subject’s partners who defected in a given round, the less likely that person was to co-operate in the next—classical tit-for-tat. However, this tit-for-tat retaliation was not enough to save co-operation, and after a dozen rounds only 10-20% of the players were still willing to co-operate.

在游戏的所有版本中，大约60%的组员一开始都会彼此合作，但是，在前两个版本中，当揩油者的恶性影响随着时间扩散的时候，彼此之间的合作减少了。人们在特定的回合中受骗的次数越多，那么就更不愿意在接下来的回合中合作——这是典型的一报还一报行为。但是这种一报还一报的报复不能够拯救人们之间的合作，在进行12轮之后，只有10%到20%的参与者依然愿意合作。

In the variant where participants had some choice over whom they interacted with, though, the amount of co-operation stayed stable as the rounds progressed. When Dr Christakis and his team looked at how the relationships between players were evolving in this third version, they found that connections between two co-operators were much more likely to be maintained than links that involved a defector. Over time, the co-operators accumulated more social connections than the defectors did.

而在参与者能够选择合作对象的游戏版本中，尽管游戏不停地进行，但是合作者的数量还是能够保持稳定。当Dr Christakis 以及他的小组检视第三个版本游戏中，参与者之间的关系是如何演化时，他们发现，两个愿意合作者之间的联系比起一个合作者与一个叛徒的状况，联系更容易维持。随着时间的推移，合作者能够比叛徒积累起更多的社会联系。

Furthermore, as they were shunned, the defectors began to change their behaviour. A defector’s likelihood of switching to co-operation increased with the number of players who had broken links with him in the previous round. Unlike straightforward tit-for-tat, social retaliation was having a marked effect.

在这而且，因为人们不愿意与叛徒们一起玩，叛徒也会开始改变自己的行为。因为人们在之前的回合里和他们断绝关系，叛徒转变成合作者的可能性也会增加。与直接的一报还一报不同，社会报复有着明显的效果。

The next question, then, is whether such a mechanism holds outside the laboratory. To find out, Dr Christakis has forged links with some anthropologists. They hope to report the answer soon.

然而，第二个问题是，在实验室外这种机制是否依然适用。为了找到问题的答案， Christakis已经与一些人类学家取得了联系。他们希望很快能够得出答案。