Fear is a strong negative emotion caused by external stimuli and associated with reactions of avoidance, self defense, and escape.

Fear is one of the primary human emotions, together with joy, anger, and grief. Fear refers to feelings elicited by real dangers and is different from anxiety. Anxiety is not always precipitated by external danger and is often out of proportion to any actual threat. Fear may be precipitated by exposure to trauma or by frightening information. Repeated or prolonged exposure to fear (for example, soldiers or caregivers in crises) can lead to psychological disorders such as combat fatigue, which is characterized by long-term anxiety and emotional disturbance.

Fear is expressed by a series of physiological changes produced by the autonomic nervous system and adrenal glands. Fear produces increased heart rate, rapid breathing, tense or trembling muscles, sweating, and dry mouth. During dangerous experiences, blood is diverted from parts of the body to the areas where energy is most needed, either to run from danger or to protect oneself. This instinctive reaction is known as the fight-or-flight response. A sudden diversion of excess blood from the brain may also cause fainting. For animals, fainting can serve as an adaptive function to protect them from predators. However, the sensation of fainting, for humans, is frightening in itself. In the 1880s, William James (1842–1910) concluded that the physiological changes associated with fear actually constitute the emotion itself (e.g., “we are afraid because we tremble” ).This view has been challenged by cognitive psychologists since the 1950s.

Fears first appear in infants at about seven months of age. Young children generally have more fears than older people and their fears are experienced more intensely. Researchers disagree about the degree to which fear is innate or learned; behaviorists argue that it is largely learned. Animals have been conditioned to fear previously neutral stimuli through various methods, including association. Innate fears such as fear of loud noises, pain, and injury appear to be universal. The Moro reflex, also known as the startle reflex, is an involuntary response that is present at birth and usually disappears between the ages of three to six months. The reflex occurs when infants are startled by a loud noise or other environmental stimulus, or feel that they are falling. The reflex causes babies to extend their arms, legs, and fingers, and arch their back. Species-specific innate fears have also been documented: Some animals show a fear of hawk-like creatures; humans and other primates have an instinctive fear of snakes.

When individuals confront real danger, fear can be an important means of self-preservation. However, many people are plagued by chronic unrealistic fears (including phobias and obsessions), which severely diminish their ability to function in society. Pathological fears can be reduced through drug treatment, but results are temporary and do not address the root cause of the problem. Mental health professionals offer various types of psychological therapies; clinicians either treat fear through a psychodynamic approach or address the fear directly through behavioral therapy. Behavioral techniques include desensitization (gradually increasing exposure to the feared object), flooding (sudden, intensive exposure to the feared object or stimulus), and modeling (observing another person being exposed to the feared object without being harmed).

See also Behavior therapy ; Fight/flight reaction ; Instinct ; James, William; Posttraumatic stress disorder (PTSD).



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