Who coined the phrase "flight or fight reaction"?

The phrase "flight or fight reaction" was coined by Walter Cannon. This term describes the physiological and psychological response that occurs in individuals when they are faced with a perceived threat or danger, leading to a decision to either confront the threat (fight) or escape from it (flight).

Cannon's work in the early 20th century provided a comprehensive understanding of how these responses are linked to the sympathetic nervous system and the release of stress hormones such as adrenaline. His research emphasized the physiological changes that accompany this reaction, such as increased heart rate, heightened alertness, and energy mobilization, all of which prepare the body to deal with a perceived threat effectively.

While Hans Selye is known for his research on stress and the general adaptation syndrome, and John Watson is associated with behaviorism, their contributions do not pertain directly to the concept of the "flight or fight" response as Cannon's does. Sigmund Freud's theories focused more on the roles of the unconscious mind and psychosexual development rather than physiological responses to danger. Therefore, Cannon's specific association with the "flight or fight reaction" makes him the correct answer to this question.