Game relativity: How context influences strategic decision making.

Existing models of strategic decision making typically assume that only the attributes of the currently played game need be considered when reaching a decision. The results presented in this article demonstrate that the so-called "co-operativeness" of the previously played prisoner's dilemma games influence choices and predictions in the current prisoner's dilemma game, which suggests that games are not considered independently. These effects involved reinforcement-based assimilation to the previous choices and also a perceptual contrast of the present game with preceding games, depending on the range and the rank of their co-operativeness. A. Parducci's (1965) range frequency theory and H. Helson's (1964) adaptation level theory are plausible theories of relative judgment of magnitude information, which could provide an account of these context effects.