The “Fight or Flight” Idea Misses the Beauty of what the Brain Really Does

Lisa Feldman Barrett is a professor of psychology at Northeastern University. She is the author of several books, including How Emotions Are Made: The Secret Life of the Brain.

When a person views a photograph of a hairy, looming spider or a slithering snake in a laboratory experiment, scientists usually see markers of increased electrical activity deep in that person’s brain, in a region called the periaqueductal gray (PAG). When a caged mouse smells a cat and freezes, scientists observe similar changes in the mouse’s PAG. What’s the obvious conclusion? The PAG controls fight-or-flight responses of mammals in threatening situations.

But what if brains don’t have dedicated circuits for fighting and fleeing? People clearly experience threats, but is threat detection really a primary mode of the brain with its own neural circuitry? A body of recent evidence from my lab and elsewhere suggests that we don’t go through life constantly detecting threats and reacting with flight-or-fight circuits. Rather brains operate mainly by prediction, not reaction. All brains constantly anticipate the needs of the body and attempt to meet those needs before they arise. They seek to reduce uncertainty to survive and thrive in circumstances that are only partially predictable.

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