a model or set of rules and assumptions used to understand various behaviors in mathematical terms. Formal theories often are developed and studied in the field of political science and psychology. An example of a formal theory is the so-called prisoner’s dilemma model, which can be applied to various situations in which participants have to decide between the costs and benefits of cooperating or competing. The model uses a series of rules to determine the outcomes of various behaviors when two suspects separately have the option to confess or refuse to speak about a potential crime.