Boo! The physiology of fear

Jennifer Davis

What scares you?

What pulses the blood and tenses the skin?

Is it the noise outside when you're home alone that forces you to drag your eyes to the window even as you throb with the fear that a face will be staring back at you, that the mere act of looking will conjure a deadly stranger.

AHHH! Gotcha.

Alfred Hitchcock knew what he was talking about when he said, "There is no terror in the bang, only the anticipation of it."

But why do we seek the terror? And why do some things that terrify you -- snakes, birds, clowns -- seem interesting, pleasing and laughable to others?

"Fear is more than a state of mind; it is chemical," writes Marc Siegel in the December 2005 issue of Scientific American Mind. "The feeling of alarm arises from the circuitry of our brains, in the neurochemical exchanges between nerve cells. Fear is a physical reaction to a hazard. As long as the danger is direct and real, fear is normal and helps to protect us. Fear also has a genetic component. A rat will recoil from the odor of a fox, even if that rodent has spent its whole life in a laboratory. Likewise, we humans are automatically apprehensive about situations that once threatened our ancestors."

Hmmm, so that genetic component might not explain a fear of clowns, but it might shed light on a more common fear: the dark. For our ancestors, the dark hid predators and a dangerous landscape. For us, not so much.

Roxy Baker readily admits her fears: "I'm scared of the dark. I see things in the dark that aren't there."

As a past president of the Peoria Jaycees who has helped build and staff at least five haunted houses for the group's annual fund-raiser, Baker says she's much happier behind the mask.

"I hate haunted houses, and I hate scary movies. They give me bad dreams."

But she knows what works.

"I think what scares (people) -- it's not the stuff out in the open, the gore. It's the very basic jumping out of a dark hallway and yelling. That scares them more than anything."

That, and clowns. Clowns are scary, says Baker.

"One year we had a clown room, and we had several people freak out. I saw a man cry."

Understanding your fear

Fear comes from a primitive part of our brain, an almond-shaped region called the amygdala, according to Joseph LeDoux, a neuroscientist at New York University who has spent 20 years studying fear, as well as writing and lecturing extensively on the topic.

"The so-called fear system of the brain is very old, evolutionarily speaking, and it is very likely that it was designed before the brain was capable of experiencing what we humans refer to as 'fear' in our own lives," writes LeDoux in an overview of his work through the LeDoux Laboratory. "Evolution seems to have gone with an 'if it ain't broke, don't fix it' rule when it comes to the fear system of the brain. The things that make rats and people afraid are very different, but the way the brain deals with danger appears to be similar. We can, as a result, learn quite a lot about how emotional situations are detected and responded to by the human brain through studies of other animals."

Physically, a lot happens to your body when you're afraid: your heart races, breathing quickens, your stomach and intestines are inhibited -- all of this so the blood supply can be used for your muscles. Your pupils dilate so you can see better. Even your lacrimal glands, which produce tears, shut down temporarily so crying isn't an option.

All of this is in preparation for the "fight-or-flight response," which was first described in 1915 by Harvard physiologist Walter Cannon.

Just gauging the body's physical reaction, fear can look like a host of other emotions -- anger, depression, love -- because the body doesn't have a lot of ways it can react.

"But, clearly, love is not having the bejesus scared out of you at the haunted house," says Dr. Timothy Bruce, professor and interim chair of the department of psychiatry and behavioral medicine at the University of Illinois College of Medicine at Peoria. "Physically, they're very similar. The difference is the emotion and what the brain is


Bruce has a theory on why we like scary stuff.

"It's kind of cool to feel that thrill but, in actuality, be safe," he says. "In general, a lot of people like it as long as it's within their control -- amusement rides, haunted houses, scary movies. If we don't stir up our systems every once in a while, we get bored. Some people like it more than others though."

Interestingly, LeDoux notes, "Many of the most common psychiatric disorders that afflict humans are emotional disorders, and many of these are related to the brain's fear system."

Simply put, some of us can have fun scaring ourselves silly at horror flicks, but the same part of our brain that allows that may also be responsible for crippling fear that disrupts our lives: our phobias.

According to The American Psychiatric Institute for Research and Education, nearly 8 percent of American adults suffer from a phobia in any given year.

A phobia is an irrational and excessive reaction to an object or situation. Symptoms can include: feelings of panic, dread, horror or terror; recognition that the fear goes beyond the actual threat or what might be considered normal; automatic and uncontrollable reactions; rapid heartbeat and shortness of breath and an overwhelming need to flee the situation, as well as extreme measures to avoid the object or situation.

While much is still unknown about what causes phobias, your fear may be related to your parents' fear, experts believe. An example of a common learned phobia may be the fear of snakes, but brain chemicals, genetics and traumatic experiences also appear to play a role.

LeDoux believes his work may someday "reveal important information both about where our emotions come from and what goes wrong in emotional disorders. And as we learn more, we hope to also figure out how to better treat and even prevent these conditions."

This Halloween, hopefully your fear will all be in fun.

And remember, as Norman Bates in "Psycho" said: "We all go a little mad sometimes."

Jennifer Davis can be reached at (309) 686-3249 or