My purpose in this paper is to highlight some of the central ideas contained in Heider's theory, to present them in a systematic way, and to show their relevance to developments in several central fields of contemporary social psychology.

Psychologists have long understood the power of the consistency principle to direct human action.

The tendency to be rational is the consistent and hence predictable element in human behavior. (p.4)

We humans replace the bulk of both our "hardware" (e.g., our cells) and our "software" (e.g., our memories) many times in our life span. Nonetheless, we perceive ourselves as stable and permanent. Likewise, we perceive objects other than ourselves as permanent. Or rather, what we perceive as objects are those aspects of the world that display a certain permanence. For instance, when observing the ocean, we perceive the moving waves as objects because they display a certain permanence, even though the water itself is only bobbing up and down. Similarly (…) we perceive only those aspects of the world that are fairly stable against quantum decoherence.

A person is known by the behavior he displays consistently. An experiment by Himmelfarb (1972) makes the important point that consistency in other persons' characterizations of an actor carries more weight if they are based on observations in dissimilar rather than similar situations. The other side of the coin is that a person's inconsistent behavior is attributed not to him but to circumstances.

Organizations and institutions permit stable expectations to be formed by each member of the group as to the behavior of the other members under specified conditions.

Towards the close of the eighteenth century, Johann Gottfried Herder boldly proclaimed this idea, asserting that each age and every people embody ideals and capacities peculiar to themselves, thus allowing a fuller and more complete expression of the multiform potentialities of humankind than could otherwise occur. Herder expressly denied that one people or civilization was better than another. They were just different, in the same way that the German language was different from the French.

Traits like verbal fluency, adaptability, impulsivity, and humility are stable from childhood through adulthood.

Her face kept changing and that bothered me as well. Why were human beings so unstable? The door and the curtains and the supply cabinet didn't continually change their appearance.'

Institutions are human behavior, and they are, therefore, to be explained by the characteristics of that behavior.

The philosopher kings behind what passed for management psychology were Ivan Pavlov and, later on, B. F. Skinner, who believed that if you discovered and applied just the right stimulus, people would behave however you wanted.

The continuity of physical traits and the limitation of the effects of environment to the individual only are now so thoroughly recognized by scientists that it is at most a question of time when the social consequences which result from such crossings will be generally understood by the public at large. As soon as the true bearing and import of the facts are appreciated by lawmakers, a complete change in our political structure will inevitably occur, and our present reliance on the influences of education will be superseded by a readjustment based on racial values.