I have to start this blog post with a confession. I’ve never been interested in game theory, and even though I took a few game theory courses in undergrad, I always struggled to understand everything. However, I was feeling somewhat uneasy about game theory (or at least parts of it) and couldn’t really explain why. It was more emotional.
I still remember a recent conversation about game theory with a fellow undergraduate student (who was probably also a recent graduate). She quite liked it and gave a great discussion about why it is useful and good. One of the criticisms I voiced at the time was that game theory has difficulty explaining cooperation.
What I wondered about is how exactly game theory can explain cooperation, assuming that people are selfish and maximize their (narrowly constructed) expected utility. did. She answered: “Oh, that’s not a big deal. Assuming an iterative game, it makes sense to cooperate.” In itself, that answer seemed convincing. After all, if you expect to meet many times, you should adjust your behavior accordingly. And perhaps it is truly “rational” to cooperate without betraying. So I left it alone that day. However, I couldn’t completely shake off my anxiety about that solution.
Things changed when I read Joe Henrich’s monumental work, The Strangest People in the World, published in 2020. Henrich does a lot in this booklet, but he also touches on prehistoric life. And in an interesting passage, he reflects on human interaction. Henrich (p. 303) writes:
Weird people tend to think that trade is simple. We have yams and you have fish. Eat fish instead of yams. easy. But this is misguided. Imagine William Buckley’s Australian hunter-gatherer society trying to barter fish for yams. In this world, other groups were often hostile, and strangers were often killed on sight. To hide their nocturnal location, the band erected a low grass fence around their campfire to avoid being seen from a distance. If I show up at your campfire with replacement yams, why don’t you kill me and take them? Or maybe you thought all we had to offer was a poisonous yam that would slowly poison you and your band. Under such circumstances, it is difficult to understand how smoothly flowing trade, which was probably common throughout the evolutionary history of our species, could emerge.
If Henrich is correct, we cannot simply assume that there is a second round, let alone a game with infinite rounds. Sure, maybe the normal kind of interaction would be them trying to kill each other. Or the two will refrain from interacting altogether.
But if for some reason there was a second round, that would be assuming there was a first round of interaction and it was peaceful. For example, we swapped yams for fish. At least we didn’t kill each other with spears and poisoned yams. But this is, or at least very close to, cooperation in the sense of peaceful, coordinated, mutually beneficial interaction, even if it is in a very crude and rudimentary form.
Following Henrich, the sheer fact that there is a second round of dialogue, that is, even if our game started in the first place, it does not end in the first place (because Either I killed you or you killed me), or at least that interaction was so distant that none of us see any reason to interact again). requires a high level of cooperation.
However, this means that it is a requirement for game theorists to envision repeated games in order to demonstrate that cooperation is possible and indeed follows game-theoretic scenarios. They assume that when people face an iterative, even infinitely repeated game, i.e., they do not kill each other on first sight, their interactions are characterized by basic cooperation, or at least peace. We have already assumed that there is. Therefore, game theory secretly assumes cooperative and peaceful interactions to explain cooperation. And that’s a problem.
I would like to return to the statement I made at the beginning of this article. I’m not an expert in the field of game theory. I’m just an outsider advocating my own ideas about game theory, and certainly a critic who may miss the forest for the trees. But maybe someone who writes a comment on this blog can tell me where my reasoning is wrong. Or maybe my criticisms have some point and game theory has some work to do.
Max Molden is a PhD student at the University of Hamburg. He has collaborated with the European Students for Freedom and Prometheus (Das Freiheitsinstitut). He publishes regularly in Der Freydenker.
