Fear is omnipresent and is one of the emotionsOpens in new window about which we have the most knowledge. It may be a functional reaction, leading to life-saving behavior, or dysfunctional, as in experiencing a phobiaOpens in new window. Fear is seen in all mammal species and often looks highly similar from one animal to the next.
Fear is experienced as unpleasant. Behaviorally, there may be an immediate freezing, in which the individual becomes very still and quiet, or a startfle reflex could occur, involving a jerking of much of the body and possibly jumping, or a more limited response such as eye blinking, or something in between.
During this immediate reaction, the fearful person or animal is vigilant, attending closely to the potential danger. Thus, perceptually, fear is seen as a narrowing or focusing of attention toward a certain object or situation.
Physiologically, fear is an activation of the sympathetic nervous systemOpens in new window, preparing the person to fight or fleeOpens in new window. Heart rate, blood pressure, and respiration all increase, stress hormones are released, energy is mobilized, and a number of other changes occur in the body.
In the brain, it is clear that at least one structure, the amygdale (an almond-shaped area in the interior of the brain) is involved in fear. For instance, LeDoux (1996) discusses how the amygdale receives sensory information from another brain structure, the thalamus, and begins to inititate fear responses (e.g., increased heart rate).
Additionally, as a number of researchers have shown, damage to the amygdale can render an animal unable to learn new fears through conditioning (e.g., Schafe et al., 2000). Particular brain chemicals, such as the chemical messenger GABA (gamma-aminobutyric acid), which inhibits the firing of neurons, are involved in fear. LeDoux (1996) and Kalat and Shiota (2007) discuss physiological, neuroanatomical, and neurochemical aspects of fear.
Many researchers distinguish fear from a related emotion: anxietyOpens in new window. Both emotions involve a perceived threat. With both, the reaction itself includes a subjective experience that is unpleasant and a physiological response.
The two emotions differ in a few ways. First, fear involves a clear stimulus: something potentially threatening happened, and the individual is reacting with a fear response. Anxiety is more general and diffuse.
When someone is anxious, there is a dread about something that could happen or that is about to happen, or the person may not even know the source of the anxiety.
Second, and related to the first point, as Epstein (1972) described in his classic chapter, fear is associated with coping, whereas anxiety means a failure in ability to cope. Epstein described fear as an “avoidance motive.” The individual may fight or flee, unless there is some impediment to these actions, and the fear can be resolved. With anxietyOpens in new window, threat is perceived but the arousal is “undirected,” and avoidance or defensive reactions do not clearly resolve the emotion.
Third, fear and anxiety have overlapping but somewhat different physiological reactions and somewhat different physiological mechanisms. The experience of fear involves an acute fear response (e.g., increased heart rate) when an eliciting stimulus is present. People who experience anxiety have relatively high resting sympathetic nervous system activity but may react less intensely to acute stressors (Hoehn-Saric & McLeod, 2000).
Addionally, while the amygdale is clearly involved in fear, the stria terminalis (a different brain area) may be more directly involved in anxiety (see Walker, Toufexis, & Davis, 2003).
Distinguishing between fear and anxietyOpens in new window is helpful for a number of reasons, including that the distinction aids in the understanding of the variety of anxiety disorders. On the basis of the behavioral and physiological responses associated with them, specific phobiasOpens in new window—for which a clear stimulus is present (i.e., dog phobia, water phobia, claustrophobia)—are fears.
Generalized anxiety disorderOpens in new window and panic disorderOpens in new window more closely resemble anxiety. Posttraumatic stress disorderOpens in new window and social phobiasOpens in new window have elements of both fear and anxiety. The ongoing research on fear and anxiety is likely to lead to a better understanding of these experiences and perhaps more effective treatments for the anxiety disorders.
- Ohman, A. (2008). Fear and anxiety. In M. Lewis, J.M. Haviland-Jones, & L. F. Barrett (Eds.), Handbook of emotions. (3rd ed., pp. 709 – 729). New York: Guilford.
- Epstein, S. (1972). The nature of anxiety with emphasis upon its relationship to expectancy. In C.D. Spielberger (Ed.)., Anxiety: Current trends in theory and research (Vol. 2, pp. 291 – 337). NewYork: Academic Press.
- Hoehn-Saric, R., & McLeod, D. R. (2000). Anxiety and arousal: Physiological changes and their perception. Journal of Affective Disorders, 61, 217 – 224.
- Kalat, J.W., & Shiota, M.N. (2007). Emotion. Belmont, CA: Thomson Wadsworth.
- LeDoux, J. (1996). The emotional brain: The mysterious underpinnings of emotional life. New York: Touchstone.
- Walker, D.L., Toufexis, D.J., & Davis, M. (2003). Role of the bed nucleus of the stria terminalis versus the amygdale in fear, stress, and anxiety. European Journal of Pharmacology, 463, 199 – 216.