Dynamic concepts

Lewin used the term “dynamic” to refer to conditions of change, especially to forces,. A primary dynamic concept in the person system is the need, which was Lewin’s chief motivational construct. A need arouses tension, which is then reduced or equalized as the need is met through either action or ideation. Regardless of the method used to restore the person’s equilibrium, Lewin identified three stages through which needs typically proceed; hunger, satiation and oversatiation. Those sates are associated with another dynamic concept, that of valence. A valence was defined as the value with which a person invests a particular environmental region in terms of its potential for need satisfaction. A positive valence is associated with the hunger stage of need arousal, a neutral valence with satiation and a negative valence with oversatiation. For example, hungry person are likely to be strongly attracted to a restaurant, the investment lessening as their hunger is satisfied. Should they eat too much, they are apt to react to the restaurant with actual aversion.

In Lewinian terms, then and unsatisfied need arouses tension, tension induces disequilibrium, and person react to restore their equilibrium through either realistic or unrealistic means. The actual motive power for making the restoration is reserved in Lewin’s system for the concept of force, a dynamic construct diagrammatically represented by a vector. The need arises in the person, but the force exists in the environment. A force of sufficient strength pressures persons toward tension reduction, and they select a path into the environment by which to accomplish the reduction. They may also respond by restructuring the environment or simply by changing their perception of the situation, so that it no longer arouses tension in them. Their reactions are largely influenced be what Lewin called his level of aspiration, the degree of difficulty presented by the goal toward which they are striving. Their levels of aspiration establish the goals they invest with the highest positive valence or perceived reward and those goals, in turn, are influence by a number of subjectively determined factors, as well as by social pressures and group evaluations.

The concept of level of aspiration has probably promoted more research than any other single Lewinin construct, and its implications are of continuing importance. Much of the current works in achievement motivation, for example, is based on Lewin’s finding that difficult goals carry greater positive valence that do easier ones.