The<unk>  refers to a hypothesis on the origin and nature of emotions developed independently by two 19th-century scholars, William<unk>  and Carl<unk> . The theory states that within human beings, as a response to experiences in the world, the autonomic nervous system creates physiological events such as muscular tension, a rise in heart rate, perspiration, and dryness of the mouth. Emotions, then, are feelings which come about as a result of these physiological changes, rather than being their cause.<unk>  and<unk>  arrived at the theory independently.<unk>  specifically stated that vasomotor changes are emotions. (Ex. A person rationalizes that because they are crying, they must be sad.)<unk>  elucidated his concept as:
The notion of causality is a difficult one. The theory has been<unk> ly disfavored in modern times. Some evidence to support it, however, may come from the fact that sufferers of various psychological challenges such as panic disorders often experience psychoemotional trauma after physiological responses arise in the body, responses which individuals are conditioned to associate with a particular emotional state but which can, via therapy, be dissociated.
This theory was challenged in the 1920s by psychologists such as Walter Cannon and Philip Bard, who theorized that physiological changes are caused by emotions (collectively known as the Cannon-Bard Theory of Emotion).
The third theory of emotion is called the Schachter & Singer's Two factor theory of emotion. This theory states that emotions are a direct result of an analysis of the surroundings.
James-Lange theory
Cannon-Bard theory
Chaos theory
Quantum mechanics
Weber–Fechner law
Franck-Condon principle
Host-guest chemistry
Hebbian theory