ABSTRACT
Traditionally, the study of thinking strategies in problem solving and decision making has concentrated on the analysis of a single person making a decision, where the normatively “right” solution can be found without considering the behavior of anyone else. Specifically designed tasks are presented to participants and strategies of thinking are singled out through the sequence of answers of each participant to the experimental situation. The experimental situations correspond to scenarios of everyday life where an individual is facing a problem or a difficulty which is impossible to bypass or to solve using a routine. However, our strategies often do not depend on a specific problemsolving scenario but on actions taken by other persons interacting with us. One of the most powerful analytical tools for describing interactive decision making is game theory (see, for an introduction, Osborne & Rubinstein, 1994). Game theory is a theory of interactive decision making. Like normative theories of individual decision making, its standard behavioral assumption is that individuals are rational, that is, they have well-defined preferences and maximize on the ground of such preferences. Furthermore, game theory specifies the normative thinking procedures individuals should follow to find
the “solution” of the game. It is common to find in game theory a terminology that may be a source of ambiguity in this book, especially regarding the words strategic and strategy. A strategic interaction is a situation in which the outcome of an individual decision is conditional to decisions taken by others. A strategy is a complete plan specifying which action or sequence of actions an individual will take in a strategic interaction, given the rules of the game (including the timing of actions) and the moves the other players might play. Individual decision making can be considered as a special kind of game in which there is only one decision maker, interacting against “nature,” whose “moves” specify in which state the player will find himself (e.g., in a gamble, nature draws the actual outcome of the lottery). When referring to strategy and strategic interaction, or to play against nature, we refer to the current use of such terms in game theory. On the converse, when we refer to reasoning strategies, we do it in the usual way psychologists do.
