What makes us afraid? Snakes, the dark, rejection, love, spiders, the unknown, public speaking, flying, storms, failure — though the reasons are varied, we are all hardwired to feel fear. Or are we?
What about people who never seem to be afraid? Or the small percentage of the population that literally cannot feel fear? Why are there kids completely unafraid of taking risks and then others who seem afraid of everything?
Fear’s purpose is to keep us from harm, but what if it holds us back from what we really want?
The biology of fear
First, some facts: There is no single fear switch for humans; responding to threats involves multiple areas of the brain. We’re not 100% how, but scientists have found the amygdala—almond-shaped bundles of neurons buried deep in the brain, just above the brain stem—central to the process.
“When you sense something potentially dangerous, the amygdala sends excitatory signals to other parts of the brain, effectively saying, ‘Hey everyone, pay attention!’” says Bambi DeLaRosa, a researcher on threat processing. The areas of the brain associated with language and memory also become active in the face of fear. If the amygdala sounds the alarm, the other areas help evaluate the threat level and how you respond.
But people with the extremely rare Urbach-Wiethe disease have calcium deposits in their brains, making it impossible for them to process fear. Studies have found their amygdala completely calcified, so there’s nothing to signal for fear signs like sweating palms or a racing heart to begin. Researchers have identified only 400 people in the world with this condition.
What’s particularly striking about Urbach-Wiethe is that fear has long been critical for human survival, so living without fear can be quite dangerous. Studying subjects with this condition has also given us insights to how we deal with emotions and drives. Since people can survive without fear, perhaps it isn’t as necessary as we’ve assumed. Other paths, like logic, can take us to the correct behaviors that help us survive.
