For other uses, see Fear (disambiguation).

Fear is one of a group of reactions in life forms with a long history of survival advantages for the owner.

It has compounded from simple reactions like a flower closing it's petals at night, and in humans has many built on symbiotic subroutines, based on triggers of data and internal data construction models or thoughts or reactive peptides and other sub-systems in the human brain.

Although it is an arbitrary classification, some techniques and chemicals can suppress fear.

It occurs during the manifestation of a real or perceived attack on the system, its evolutionary purpose being to incite the system to react. Fear also can be described as a feeling of extreme dislike towards certain conditions, objects, people, or situations such as: fear of darkness, fear of ghosts, etc. Personal fear varies extremely in degree from mild caution to extreme phobia and paranoia. Fears may be a factor within a larger social network, wherein personal fears are synergetically compounded as mass hysteria.

Fear may underlie some phenomena of behavior modification, although these phenomena can be explained without adducing fear as a factor in them. Furthermore, application of aversive stimuli is also often ineffective in producing change in the behaviour intended to be changed. Fearing objects or contexts can be learned; in animals this is being studied as fear conditioning, which depends on the emotional circuitry of the brain. It is one of the basic emotions and is linked heavily to the amygdala neurons.

Some philosophers have considered fear to be a useless emotion; other thinkers note the usefulness of fear as a warning of potentially unpleasant situations or consequences. Still others consider that fear is the fuel that feeds the ego's (as in "separating/judgmental agent") engine. Note that "fear" in the sense of "God Fearing" means "To regard with reverence and awe".

Fear can be described by different terms in accordance with its relative degrees. Fear covers a number of terms - worry, anxiety, terror, fright, paranoia, horror, panic (social and personal), persecution complex and dread.

• "Paranoia" is a term used to describe a psychosis of fear, described as a heightened perception of being persecuted, false or otherwise. This degree of fear often indicates that one has changed their normal behavior in radical ways, and may have become extremely compulsive. Sometimes, the result of extreme paranoia is a phobia.

• "Distrust" In the context of interpersonal fear, is sometimes explained as the inward feeling of caution, usually focused towards a person, representing an unwillingness to trust in someone else. Distrust is not a lack of faith or belief in someone, but a feeling of warning towards someone or something questionable or unknown. For example, one may "distrust" a stranger who acts in a way that is perceived as "odd." Likewise one may "distrust" the safety of a rusty old bridge across a 100 ft drop.

• "Terror" refers to a pronounced state of fear, which usually occurs after the state of horror, when someone becomes overwhelmed with a sense of immediate danger. Also, it can be caused by perceiving the (possibly extreme) phobia. As a consequence, terror overwhelms the person to the point of making irrational choices and non-typical behavior.

The causes of fear can vary to a surprising degree; fear is to a certain extent a "cultural artifact" (Clifford Geertz). In 19th century Britain, one of the biggest fears was of dying poor, unmourned, unremembered, and possibly ending up on an anatomist's dissection table. By the early twentieth century, this had given way to a fear of being buried alive, to the extent that those who could afford it would make all sorts of arrangements to ensure this would be avoided (e.g. glass lids for observation, and breathing pipes for survival until rescued). During the Second World War, fear of death by bombing was much less prevalent than during World War I, even though many more bombs fell; air wardens would complain of civilians continuing to gossip on street corners instead of taking shelter. Similarly, when cars were new in the early 1900s, dislike of them from the public pushed laws requiring a guard with a red flag to walk in front of it to warn the public of traffic.

Fear may also be caused by a traumatic accident. For example: if you fall into a well and are struggling to get out, you may fear either closed spaces (claustrophobia) or fear of water (hydrophobia.) However, fear can also be triggered naturally. You may naturally fear spiders, or heights, not because of a traumatic accident, but because of a natural feeling.

Fear may be a consideration in determining the wrongness of acts, in some views. Actions done under stress of fear, unless of course it be so intense as to have dethroned reason, are accounted the legitimate progeny of the human will, or are, as the theologians say, simply voluntary, and therefore imputable. The reason is obvious, such acts lack neither adequate advertence nor sufficient consent, even though the latter be elicited only to avoid a greater evil or one conceived to be greater. Inasmuch, however, as they are accompanied by a more or less vehement repugnance, they are said to be in a limited and partial sense of involuntary.

Since fear diminishes freedom of action, contracts entered into through fear may be judged invalid; similarly fear sometimes excuses from the application of the law in a particular case; it also excuses from the penalty attached to an act contrary to the law. The cause of fear is found in oneself or in a natural cause (intrinsic fear) or it is found in another person (extrinsic fear). Fear may be grave, such for instance as would influence a steadfast man, or it may be slight, such as would affect a person of weak will. In order that fear may be considered grave certain conditions are requisite: the fear must be grave in itself, and not merely in the estimation of the person fearing; it must be based on a reasonable foundation; the threats must be possible of execution; the execution of the threats must be inevitable. Fear, again, is either just or unjust, according to the justness or otherwise of the reasons which lead to the use of fear as a compelling force. Reverential fear is that which may exist between Superiors and their subjects. Grave fear diminishes willpower but cannot be said to totally take it away, except in some very exceptional cases. Slight fear (metus levis) is not considered even to diminish the will power, hence the legal expression "Foolish fear is not a just excuse".

Fear can be distinguished into serious fear (metus gravis) and trifling fear (metus levis). The first is such as grows out of the discernment of some formidable impending peril: if this be really, and without qualification, of large proportions, then the fear is said to be absolutely great; otherwise it is only relatively so, as for instance, when account is taken of the greater susceptibility of certain classes of persons, such as children. Trifling fear is that which arises from being confronted with harm of inconsiderable dimensions, or, at any rate of whose happening there is only a slender likelihood.

In fear, one may go through various emotional stages. A good example of this is the cornered rat, which will try to run away until it is finally cornered by its predator, at which point it will become belligerent and fight back until it either escapes or is captured.

The same goes with most animals. Humans can become very intimidated by fear; causing them to go along with one's wishes without caring about their own input. They can also become equally violent, and can even become deadly; it is an instinctive reaction caused by rising adrenaline levels rather than a consciously thought-out decision. This is why in many cases the full penalty cannot be made in cases of the court of law.

Physiologic effects of fear can be better understood from the perspective of the sympathetic nervous responses (fight-or-flight), as compared to parasympathetic response, which is a more relaxed stated:

• the brow or other parts of the body sweat profusely in order to keep the body cool as it flees. (More accurately, perspiration occurs due to blood being shunted from body viscera to the peripheral parts of the body - the fight-or-flight response. Blood that is shunted from one's viscera to limbs, etc., will transfer, along with oxygen and nutrients, heat - thus heat transfer from blood best explains perspiration. While it's true that cooling is an effect of this, it is not the primary reason for shunting blood to the periphery.)

• the muscles tighten in preparation for combat. (More accurately, not all muscles are created equal, such that smooth muscle would generally not contract under sympathetic control. Smooth muscles - such as those associated with one's gastrointestinal tract - are generally active only when influenced by the parasympathetic nervous system. While somatic muscle - or voluntary muscles, biceps etc. - do not generally contract involuntarily, except in nerve circuits in a reflex arc that immediately respond to heat, etc.. However, since blood is shunted to the body periphery, muscles receive blood, primarily for oxygen to drive metabolic responses that would be needed during a fight-or-flight event. Further, "combat" is only one option. The other one is fleeing.)

• the senses are sharpened in order to take in vaster quantities of information. (More accurately, senses are not sharpened, but merely modified - or redirected - to deal with events that have evolutionarily been the most likely to cause harm. For example, the dilation of the pupils and relaxation of the lens, allowing more light to enter the eye, which is more conducive to far vision. Or fine body hair standing up to alert one to creeping insects, etc.)

• the hands usually as a reaction open and cover face. (This doesn't seem consistent with wanting to heighten the senses. Further, one would not necessarily cover one's face in a fear response.)

• One's eyes widen (out of anticipation for what will happen next)
• The pupils dilate (to take in more light)
• The upper lip rises
• The brows draw together
• Lips stretch horizontally.

•  This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed. (1913). Catholic Encyclopedia. New York: Robert Appleton Company. {{cite encyclopedia}}: Missing or empty |title= (help)

• Angst
• Phobia
• Night terror
• Appeal to fear
• Culture of fear
• Shame
• Guilt
• Freud
• Litany against fear
• Panic
• Strategy of tension

• Joanna Bourke (2005), Fear: a cultural history, Virago
• Corey Robin (2004), Fear: the history of a political idea, Oxford University Press
• Duenwald, Mary. "The Psychology of ...Facial Expressions" Discovery Magazine Vol. 26 NO. 1
• Krishnamurti, J. (1995), On Fear, Harper Collins, ISBN 0-06-251014-2

• Quotations on Fear
• A Buddhist View on Fear
• The Psychology of Fear
• The Smell of Fear, a Research Study
• How to Deal With Fear
• Catholic Encyclopedia "Fear (in Canon Law)"
• Catholic Encyclopedia "Fear (from a Moral Standpoint)"