JamesLange

James-Lange theory of emotion is a foundational hypothesis in the psychology of emotion. It proposes that emotions arise from the perception of physiological changes in the body in response to external stimuli. The theory was independently developed in the 1880s by William James, an American philosopher and psychologist, and Carl Lange, a Danish physician; together they are associated with the James–Lange formulation.

According to the theory, an emotionally arousing event triggers bodily changes—such as increased heart rate, faster breathing, and muscular tension—and it is the mind's perception of these changes that constitutes the emotional experience. For example, encountering a threat would produce physiological arousal; the interpretation of that arousal by the brain would be fear.

Historically, the James-Lange view faced criticism from Walter Cannon and Philip Bard, who argued that autonomic responses are too diffuse and non-specific to account for different emotions, and that cognitive appraisal is necessary for emotional experience. Subsequent research showed that emotions can occur with varied autonomic patterns, yet physiological feedback can influence emotional intensity and awareness.

Today, the James-Lange theory is considered a key historical perspective that helped establish the link between body and emotion. It influenced later theories, including Schachter and Singer's two-factor model and the concept of interoceptive awareness, and it remains a focal point in discussions of how physiological states contribute to emotional experience.