Why Humans Experience Fear

Why Humans Experience Fear

Why do we experience fear? Researchers have identified two types of instrumental behaviors: habitual instrumental behavior and action-outcome instrumental behavior. Habitual instrumental behaviors involve fixed corticostriatal circuits while action-outcome instrumental behaviors involve flexible corticostriatal circuits. Deliberative instrumental responses are prospective and engage prefrontal circuits. Non-conscious deliberation about a potential danger allows us to quickly imagine a possible solution. Conscious deliberation about danger requires longer planning and involves higher-level prefrontal circuits.

When a threat is imminent, this response prepares the body for action. It increases blood pressure, heart rate, and breathing rate to ensure adequate oxygen supply to the muscles. During a flight or fight response, the digestive system slows and the skin sweats to keep the body cool. In addition, some people feel physical sensations in their chest, hands, legs, or stomach. In some cases, these physical sensations are mild or severe.

The cerebral cortex, the part of the brain that controls reasoning and judgment, is also affected by fear. Inhibited cerebral cortex causes impaired decision-making and reduced thinking, which is why people who experience terror often scream or react violently in frightening situations. The resulting physiological changes cause the body to respond in a “fight or flight” manner. And the brain is highly regulated by these signals. If the body is under-prepared, it will likely suffer severe consequences.

While this is a complex phenomenon, it is not unusual to observe abnormal levels of fear in many people. These symptoms can limit people’s ability to enjoy life and achieve success. Approximately one in four people suffer from some form of anxiety disorder. Nearly eight percent of all people experience post-traumatic stress disorder. Thankfully, effective treatments exist to overcome these disorders. Psychotherapy and medications are effective for short-term use. There is no known cure for post-traumatic stress disorder, but they can be effective in treating symptoms of anxiety.