Who proposed the theory that the body adjusts when change threatens to be too great?

The theory relating to the body's adjustment in response to significant changes is attributed to Walter B. Cannon, who introduced the concept of "homeostasis." Cannon's work emphasized how the body strives to maintain stability amidst external and internal changes that may threaten physiological balance. This concept encompasses the idea that when a stressor or significant change occurs, the body activates various physiological mechanisms to cope and restore equilibrium.

Cannon's research laid the foundation for understanding how the body reacts to stress, highlighting the importance of the fight-or-flight response and the adrenal response in such situations. His theories are instrumental in fields like psychology and physiology, particularly concerning stress management and responses to environmental changes.