The Nuance
The Brain and Body Prioritize Adaptation, Not Balance
‘Allostasis’ is reshaping science’s understanding of disease and disorder
In ancient Greece, the top medical minds believed that the function of the human brain and body was dependent on the proper ratio of four internal fluids which were known as the “humors.” Too much or too little of any one of the humors was thought to cause pain, dysfunction, and behavioral or emotional intemperance.
This cocktail mixologist’s notion of human physiology continued to dominate medical theory until the 19th century, when doctors finally recognized that “humorism” was mostly bunk. But they couldn’t quite shake off the belief that a sick body is somehow a body out of balance.
The next big idea that emerged — one that became “the dominant explanatory framework for physiological regulation” from the late 1800s all the way up to the present — is the concept of “homeostasis.” In a nutshell, homeostasis holds that the human body has certain baseline states or “set points” that it strives to maintain. Constancy is the goal, and disease and disorder are the result of deviations from these set points or the body’s unsuccessful attempts to get back to them. Like Leonardo da Vinci’s Vitruvian Man, homeostasis holds that a healthy body and…
