Walter Cannon, a professor of physiology at Harvard University coined the term homeostasis in his book "The Wisdom of the Body" in 1932. In his work with animals Cannon observed that any change of emotional state in the beast, such as anxiety, distress, or rage was accompanied by total cessation of movements of the stomach (Bodily Changes in Pain, Hunger, Fear and Rage, 1915). These studies into the relationship between the effects of emotions and perceptions on the autonomic nervous system, the responses that led to the freeze, fight or flight response. 