Zerosum vs. Non-Zerosum Games
From Robert Wright, excerpted from an interview by WIE magazine.
"WIE: Could you explain what "nonzero sum" or "nonzero sumness" is?
RW: Yes. The basic idea of a nonzero sum game is just that there doesn't have to be a winner and a loser. When you play tennis against somebody, every point is good for one player and bad for the other one. That's a zero sum game. But if you're playing doubles, then the relationship between you and the other person on your team is nonzero sum because the point can be good for both of you or bad for both of you. You are in the same boat. Your fortunes are correlated positively. So you can both come out winners—that is, both people on a doubles team—or both be losers. In most real-life situations, what you have is a mixture of nonzero sum and zero sum dynamics. Rarely are you so completely in the same boat with someone as you would be in doubles tennis. But that's where the term "nonzero sum" comes from. The main point is that in a nonzero sum game, it's usually in your self-interest to cooperate with another person, and it is in your self-interest to do something that is good for the other person. Being in a nonzero sum situation is, in a sense, a somewhat cynical basis for moral behavior, which you might consider to be a contradiction. In other words, it's a reason to worry about the welfare of other people, but it's a reason that's grounded ultimately in your own self-interest. For example, one reason you don't want to launch a nuclear war against Russia and have a bunch of Russians die is because that would probably lead to a bunch of Americans dying. That's not a really pure form of moral concern but, on the other hand, its practical upshot is to make the world better off. Its practical consequences are, in many ways, like the consequences of truly moral behavior.
WIE: One point that you made in Nonzero was about the relationship within societies between zero sum and nonzero sum dynamics. Genetic reproduction is always a zero sum game—in other words, one set of genes wins out over the others—and the drive to reproduce one's genes is at the root of so much behavior, animal and human. But, as social or cultural systems become more complex, nonzero sum behaviors often lead to a better outcome overall, making it more likely for more organisms to reproduce.
RW: Yes. There are a lot of ways that competitive dynamics have cooperative outcomes, or as you said, that zero sum dynamics can give rise to nonzero sumness. One example is certainly found in genetic evolution, if you just look at your genome. Your genome is a team of genes that cooperate in very intricate fashion. The reason they do that is because they are united in playing a cutthroat zero sum game against other organisms, or at least they were doing that during much of evolution. That's the historical reason. So, first of all, at the level of the genome, there are all these nonzero sum cooperative dynamics that are the result of zero sum competition. But then at higher levels, as you suggest, you also get cooperation among organisms that results from competition between groups of organisms.
You see this in cultural evolution as well. One of the main reasons that societies became more complicated and more elaborately cooperative over the last eight or ten thousand years is that they were competing with other societies. Now, what's interesting about the period that we're entering now, with globalization, is that at the global level of social organization, there's no longer another huge team to compete against. There's no other planet out there that we're going to fight a war with. There still is competition in the world, economic competition and so on. But as far as large, geographically distinct populations fighting against other large, geographically distinct populations, which is a big part of human history, that, I think, or at least hope, is grinding to a halt. In part that is because war is increasingly becoming a nonzero sum game, in the sense of a lose-lose game.
The point is that I think this is all a product of a basic direction of cultural evolution. I think it was in the cards that we would reach this kind of watershed in human history. It's just a very morally and spiritually interesting watershed. What happens next—whether we make big mistakes that lead to global chaos and destruction, or we usher in an era of some harmony—depends largely on whether we accurately perceive the commonality of interest among human beings around the world, and show some interest in their welfare. In that sense, it's a challenge to our level of enlightenment.
More and more, we do have the capacity to blow up or at least ruin the whole world. Our not doing so really depends on just fundamentally getting the picture. So it's a challenge intellectually, as well as morally and spiritually. And I think it's something the world has been driving toward ever since the Stone Age." (http://www.enlightennext.org/magazine/j21/wright.asp?pf=1)