Why Humans Experience Fear
The physiological and behavioral changes associated with fear are highly correlated with the intensity of the arousal evoked by a particular physical stimulus. These changes are a result of a primitive mechanism to protect an organism from danger. It may have also evolved to help an organism avoid death. This response to threats, called a primitive fear, elicits a wide variety of behaviors. In fact, different types of fear trigger different neural structures in the brain.
Researchers have suggested that fear is a cohesive concept with fewer subtypes than memory. For example, animals lower their heads and tails when they are afraid of a threatening situation. This is similar to the behavior of humans. The underlying mechanism explains why humans experience fear. Interestingly, these behaviors are a consequence of a physiological process called arousal, which increases the likelihood of survival. The psychological mechanisms responsible for these actions depend on the type of arousal.
Regardless of the physiological mechanisms that trigger a fear response, a person’s mind is the primary cause of that response. In addition to the physical effects, the brain sends signals to different parts of the body. In many cases, these responses result in an increase in blood pressure and heartbeat. In addition to these physiological effects, a person may experience sensations in the hands, legs, or stomach. Further, when the brain perceives a threat, it generates memory-based expectations for a physical response.