What are you afraid of? Do snakes or spiders get your heart racing? Or do your palms begin to sweat if you have to fly or give a public presentation? For many people, these situations trigger the adrenaline-fueled stress reaction that's hardwired into all animals. This fear response kicks into overdrive even though there's no immediate danger. Such phobias aren't the only fear disorders to strike people. Some individuals experience panic attacks for no apparent reason. Others faced with the horrors of war, natural disasters, or physical abuse develop posttraumatic stress disorder, a sometimes-debilitating condition that can include horrific nightmares and flashbacks. All told, the National Institute of Mental Health in Bethesda, Md., estimates that 19 million people in the United States suffer from disorders that include inappropriate fear responses.

Psychologists and neuroscientists, however, are making progress at understanding how to conquer fear. It's not a simple matter of erasing scary memories. Instead, it seems that people can learn to suppress a fright reaction by repeatedly confronting, in a safe manner, the fear-triggering memory or stimulus. For specific phobias, up to 90 percent of people can be cured through such exposure therapy, says David Barlow, director of Boston University's Center for Anxiety and Related Disorders.

"All great truths begin as blasphemies."
- George Bernard Shaw