Who developed the General Adaptation Syndrome theory?

The General Adaptation Syndrome (GAS) theory is attributed to Hans Selye, who was a pioneering endocrinologist. He introduced this concept in 1936 to explain how the body reacts to stress and its various stages. Selye described three stages of the stress response: the alarm reaction, the stage of resistance, and the stage of exhaustion. This model highlights how stress can impact physiological functioning and is fundamental in understanding the body's adaptive mechanisms in response to prolonged stress. Selye’s work laid the groundwork for future studies on stress, health, and psychological responses, making his contribution significant in both medicine and psychology.