Why Humans Experience Fear
The science behind fear has been debated for centuries, but researchers are still not sure why humans experience such an emotion. It’s likely that fear is a reaction to a dangerous situation. In some cases, fear may be healthy. For example, a person may have a fear of deep water. But this fear can be overcome by learning how to swim safely. Some fear is necessary, however, such as when we encounter a threatening situation.
A study of the brain showed that the amygdala – the area responsible for fear recognition – is damaged when a person experiences a threatening event. Normally, the prefrontal cortex is responsible for overriding a fear response, but in people with phobias, the amygdala is heightened. People with phobias expect a trigger to occur, and the vivid anticipation may increase the fear response when the phobic object or situation actually occurs.
The biochemical response to fear involves the sympathetic nervous system, which stimulates adrenal glands. These hormones trigger a physical reaction, including sweating, heart rate, and dilation of pupils. Fear is a natural, evolutionary reaction, and a healthy one. Some people thrive on the adrenaline rush that comes with experiencing a frightening experience, while others are frightened by the idea. Although the biology of fear is complex, some of the chemicals involved in the biochemical response to fear are the same for positive and negative emotions.
Studies of the brain’s response to fear have largely confirmed Gray’s findings. In his own study, Nearing and Elizabeth A. Phelps found that the amygdala is affected when subjects watch an aversive event or place them in a stressful situation. This research helped scientists build a causal chain from behavioral clues to neurobiological changes. But scientists are still unclear about how this affects the brain’s response to fear.