Fear and the Brain

This is not just a metaphor: quite literally, these primitive regions control our actions and prevent abstract thoughts from occurring to us when we are terrified.
10/12/2006 12:11 pm ET Updated Nov 17, 2011

Over the last year, I've had the privilege of working on a book with Bruce D. Perry, M.D., Ph.D., who heads the ChildTrauma Academy and is one of the leading experts on how traumatic stress affects children and the development of their brains.

Reading the various "Fearless" posts-- and thinking about terror quite personally yesterday as a small plane hit a building just blocks from my home office-- I was struck by what Dr. Perry taught me about fear during our work.

Fear literally makes us stupid. It is mediated by the most ancient parts of the brain. These regions take control when we are frightened and basically turn off the areas responsible for rational thought. This is not just a metaphor: quite literally, these primitive regions control our actions and prevent abstract thoughts from occurring to us when we are terrified. The pattern can be seen on brain scans.

For most of our evolutionary history, of course, this ability to shut down more recently evolved areas like the cortex and simply act was highly adaptive. When a predator is chasing you, abstract ideas and long-term considerations are not useful: to survive, you need lightening-quick reactions, not deliberative decision-making processes. As a result, however, the more frightened you are, the more reflexive your responses will be.

What's more, because the brain changes in response to how you use it, the more time you spend in a terrified state, the more developed these lower regions become. Worse, since you are not exercising the higher regions and the connections that modulate the fear circuits, these are weakened comparatively.

This is why children raised in abusive or threatening environments so often have problems with impulse control: their fear regions are being strengthened, promoting quick reactions and thoughtless responses while the areas devoted to self-control and consideration of the consequences of one's actions are under-developed. Tragedies often result as they misinterpret neutral events as threatening and unthinkingly respond with aggression.

These properties of our brains also leave us vulnerable to terrorists and politicians who try to take advantage of our impaired reasoning when threatened-- and the longer we live in a state of fear, the worse it gets. Moreover, because our brains are designed to mirror the responses of those around us, the cycle can become self-reinforcing.

Arianna's call for an epidemic of fearlessness is exactly the right response. If we exercise our control over our fear, if we focus on responding thoughtfully, our brains will sharpen their skills in those areas. The more people participate, the more others will join in, due to mirroring effects. Virtuous cycles are as powerful as vicious ones. But we have to start them.

Note: Our book, The Boy Who Was Raised as a Dog and Other Stories from a Child Psychiatrist's Notebook: What Traumatized Children Can Teach Us about Loss, Love and Healing will be published by Basic in January. I will be blogging more about it from time to time. Any mistakes here are my own, not Dr. Perry's!