Nash equilibrium, team reasoning and cognitive hierarchy theory.

This paper comments on two experiments, carried out by Colman, Pulford and Rose, which investigate the prevalence of team reasoning. I argue that because the first experiment uses 'decomposable' games, it cannot discriminate between team-reasoning and the conceptually distinct 'prosocial' orientation. In the second experiment, Colman et al. find more support for the team reasoning hypothesis than for the rival hypothesis that subjects choose Nash equilibrium strategies. I suggest that the most credible explanation of the data is that some subjects are team reasoners while others act according to cognitive hierarchy theory.