You cannot gamble on others: Dissociable systems for strategic uncertainty and risk in the brain

This paper tests whether strategic uncertainty employs circuits in the brain that encode risk and utility, or circuits that are involved in Theory of Mind (ToM). We compare participants’ decisions in a stag-hunt game with an equivalent choice between Bernoulli lotteries where the probabilities are equal to the mixed Nash equilibrium of the stag hunt game. Behavioral data suggests that most participants are more willing to choose the payoff-dominant option in a stag-hunt game than the equivalent lottery. Neuroimaging shows that activations in the regions of the brain commonly associated with ToM are correlated with a participant's propensity to choose payoff dominant. This suggests that individuals who mentalize the other person are more likely to be cooperative than those who do not.