The Evolution of Cooperation, by Axelrod (1984), is a highly influential study that identifies the benefits of cooperative strategies in the iterated prisoner’s dilemma. We argue that the most extensive historical analysis in the book, a study of cooperative behavior in First World War trenches, is in error. Contrary to Axelrod’s claims, the soldiers in the Western Front were not generally in a prisoner’s dilemma (iterated or otherwise), and their cooperative behavior can be explained much more parsimoniously as immediately reducing their risks. We discuss the political implications of this misapplication of game theory.
In short: yes, the Prisoner’s Dilemma is important; yes, Axelrod’s book is fascinating; but no, the particular example he studied, of soldiers not shooting at each other in the Western Front in World War I, does not seem to be a Prisoner’s Dilemma. I have no special knowledge of World War I; I base my claims on the same secondary source that Axelrod used. Basically, it was safer for soldiers to “cooperate” (i.e., not shoot), and their commanders had to manipulate the situation to get them to shoot. Not at all the Prisoner’s Dilemma situation where shooting produced immediate gains.
In a way, this is merely a historical footnote; but it’s interesting to me because of the nature of the explanations, Axelrod’s eagerness to apply the inappropriate (as I see it) model to the situation, and others’ willingness to accept that explanation. I think the idea that cooperation can “evolve”–even in a wartime setting–is a happy story that people like to hear, even when it’s a poor description of the facts.
Other takes
Here are a bunch of positive reviews of Axelrod’s book, and here’s an article by Ken Binmore critizing Axelrod’s work on technical grounds.
And here’s Joanne Gowa’s review from 1986 which independently, and more systematically, makes similar points as I did in my thesis that was written at the same time.
Howdy Dr. Gelman! Your paper link has an extra http:// in the file path.
I'm interested in having a look at it once the link is ready.
Patrick,
Thanks for pointing this out. I fixed the link.
A correspondent writes:
AG: Axelrod's eagerness to apply the inappropriate (as I see it) model to the situation, and others' willingness to accept that explanation.
I don't really understand your critique of the application of Axelrod and prisoner's dilemma to soldiers in the trenches in WWII. But the one-two punch (kooky theory + mindless willingness to swallow it whole hog) is common in economics.
Economists still apply for Federal grant money to do experiments that will "disprove" John Nash's game theory.
Americans have spent millions of dollars and will probably spend millions more showing that a theory of social relationships developed by a paranoid schizophrenic is false (who knew!).