Body Reaction theory
A theory on emotion formulated and published by William James in 1884, which assumes that bodily changes occur when a stimulus is perceived and awareness of these bodily changes makes the emotion to be experienced (or felt).
Historically, Jame's theory on emotion is the first to depict emotion in a scientific approach. It was the first to contradict the old popular notion wherein the perception of the stimulus produced the experience of emotion, which in turn, brought about the physiological changes.
Compare: Hypothalamic theory