“Humans only have a 'fight or flight' response to threats.”

The idea that humans only react to threats with a "fight or flight" response is a widespread simplification of our body's complex survival mechanisms. This common understanding largely stems from the pioneering work of physiologist Walter Bradford Cannon in the early 20th century. Cannon's research, published in the 1910s, extensively described how the sympathetic nervous system prepares an animal for immediate action—either to confront a danger or to escape it. His influential findings popularized the concept of "fight or flight" as the primary acute stress response, shaping public perception for decades.

However, scientific understanding has evolved to reveal a more nuanced picture. Beyond these two well-known reactions, humans and many other animals also exhibit a "freeze" response when confronted with danger. This third, involuntary reaction involves immobilization, where an individual becomes still and unresponsive. This "playing dead" strategy can be an adaptive survival mechanism, helping to avoid detection by a predator (Review) or allowing the individual to assess an overwhelming threat before taking further action. The freeze response is a sophisticated physiological state, where the body is highly activated internally but outwardly appears paralyzed, often engaging the parasympathetic nervous system.

The persistence of the "fight or flight" myth is largely due to its historical prominence and the initial emphasis on these two active responses in early research. While Cannon's work was foundational, the "freeze" response was not as widely recognized or studied until much later, around 50 years after the initial descriptions of fight or flight. This delay in widespread scientific and public acknowledgment meant that the two-response model became deeply ingrained in common knowledge, even as subsequent research continued to expand our understanding of the full spectrum of defensive reactions to perceived threats.