Disappointment as an Evolutionary Force
An alternative, less abstract approach to standard evolutionary game theory is proposed; it is assumed that evolutionary forces do not necessarily favour expected utility maximising strategies per se, but instead, that agents choose their strategies so as to eschew disappointment they possibly experienced in past rounds. The equivalence of these two postulates is contingent on the behavioral assumptions one makes on the individuals of the population under study. It is shown that the disappointment dynamics may be implemented with a multitude of ways, which, generally, do not generate convergent results. This fact suggests that populations may be regarded as heterogeneous with regards to how individuals react to disappointing outcomes.