Stimulus-Response (S-R) or Stimulus Organism Response (S-O-R) theory in psychology is the universal law to govern the behavior of the organism. In the S-O-R description, a response (R) is observed in the relation to a stimulus (S) and then the interferences are made according to the internal process in the organism (O). SOR is the observed relationship between stimulus, organism, and responses.
A stimulus is a variable that initiates activity, for example, light sounds are stimuli since they stimulate activity. Stimulus sometimes is referred to in terms of the sense organ in which is affected e.g. visual stimulus, an auditory stimulus, and so on.
Psychologists are concerned with human and animal responses to stimuli. Responses are different depending upon the species and stimulus. For example, a blinking eye is a response to an intense light (stimulus).
Psychologists are interested in aspects of the organism, known as individual variables (O variables). O variables may be external and internal depending upon the influence of the stimulus. Age, sex, education level, personal values, aspirations, intelligence, thought are O variables.
There are two types of approaches to explaining the stimulus-response theory or relationship. Behavioraisitic and cognitive approach.
The behaviouristic approach describes that all behavior base on overt S-R associations. Neobehaviourists adopt mediation theory which explains that any stimulus may activate symbolic processes and these processes activate one another processes designated as S-R. Thus an internal response (r) may serve as a neural activation or stimulus (s) to another internal response (r), which may be a stimulus for still another internal response (r) and so on.
This model postulates an interaction of horizontal and vertical processes. Horizontal process of Stimulus-Response units chained to one another in a serial order showing behavior. The vertical process involves the expectation and assumption that there may occur interactions between these chains at different levels.
The cognitive approach oversimplifies stimulus-response views. They explain O in the S-O-R description. It reflects Gestalt psychology. Gestaltists describe that the meaning of an object is not only the result of stimulus and response but the active participation of an O in understanding his environment. Cognitive theorists claim higher mental processes are the result of chains of reinforcement. Thus, in SOR, O is a mediation that greatly contributed to the understanding of an organism’s behavior relating to the environment and response in prediction, influence, and control of behavior.