The simulation heuristic

We shall argue that assessments of propensity and probability derived from mental simulations are used in several tasks of judgment and also that they play a significant role in several affective states. We first list some judgmental activities in which mental simulation appears to be involved. We then describe a study of the cognitive rules that govern the mental undoing of past events, and we briefly discuss the implications of these rules for emotions that arise when reality is compared with a favored alternative, which one had failed to reach but could easily imagine reaching. We conclude this brief sketch of the simulation heuristic by some remarks on scenarios, and on the biases that are likely to arise when this heuristic is used.