balance theory
a particular cognitive consistency theory specifying that people prefer elements within a cognitive system to be internally consistent with one another (i.e., balanced). Balanced systems are assumed to be more stable and psychologically pleasant than imbalanced systems. The theory has been primarily specified and tested within the context of systems involving three elements. These systems are sometimes referred to as P-O-X triads, in which P = person (i.e., self), O = other person, and X = some stimulus or event. [first proposed in 1946 by Fritz Heider]