The "locus of control" is a concept in psychology that is based on the strength of an individual's belief in the amount of control that they have over life-affecting situations and experiences. Individuals can be classified as possessing either an internal or external locus of control.
Individuals who possess an internal locus of control typically assume that they possess a degree of control over circumstances and events that happen to them. However, individuals who possess an external locus of control believe that they have no control of what happens to them, which leads them to place responsibility and blame on external variables.
The concept of the locus of control was developed by the psychologist Julian Rotter. The idea was initially conceptualized in 1954 with Rotter's suggestion that human behavior is controlled by both punishments and rewards. Consequences stemming from an individual's actions would then influence the perception of the causes of the events and actions.
The locus of control was further refined in 1966 when Julian Rotter created and published a scale that measures whether an individual's locus of control is internal or external. Under this scale, there are no individuals with a completely internal or external locus of control.