Fear
is an emotional response to threats and danger. It is a basic survival mechanism
occurring in response to a specific stimulus, such as pain or the threat of
pain.
Fear
should be distinguished from the related emotional state of anxiety, which
typically occurs without any external threat. Additionally, fear is related to
the specific behaviors of escape and avoidance, whereas anxiety is the result
of threats which are perceived to be uncontrollable or unavoidable.
DESCRIPTION
The
facial expression of fear includes the widening of the eyes (out of
anticipation for what will happen next); the pupils dilate (to take in more
light); the upper lip rises, the brows draw together, and the lips stretch
horizontally. The physiological effects of fear can be better understood from
the perspective of the sympathetic nervous responses (fight-or-flight), as
compared to the parasympathetic response, which is a more relaxed state.
Muscles used for physical movement are tightened and primed with oxygen, in
preparation for a physical fight-or-flight response. Perspiration occurs due to
blood being shunted from body's viscera to the peripheral parts of the body.
Blood that is shunted from the viscera to the rest of the body will transfer,
along with oxygen and nutrients, heat, prompting perspiration to cool the body.
When the stimulus is shocking or abrupt, a common reaction is to cover (or
otherwise protect) vulnerable parts of the anatomy, particularly the face and
head. When a fear stimulus occurs unexpectedly, the victim of the fear response
could possibly jump or give a small start. The person's heart-rate and
heartbeat may quicken.
Neurobiology
The
amygdala is a key brain structure in the neurobiology of fear. It is involved
in the processing of negative emotions (such as fear and anger). Researchers
have observed hyperactivity in the amygdala when patients who were shown
threatening faces or confronted with frightening situations. Patients with a
more severe social phobia showed a correlation with increased response in the
amygdala. Studies have also shown that subjects exposed to images of frightened
faces, or faces of people from another race, exhibit increased activity in the
amygdala.
The
fear response generated by the amygdala can be mitigated by another brain
region known as the rostral anterior cingulate cortex, located in the frontal
lobe. In a 2006 study at Columbia
University, researchers
observed that test subjects experienced less activity in the amygdala when they
consciously perceived fearful stimuli than when they unconsciously perceived
fearful stimuli. In the former case, they discovered the rostral anterior
cingulate cortex activates to dampen activity in amygdala, granting the
subjects a degree of emotional control.
Suppression
of amygdala activity can also be achieved by pathogens. Rats infected with the
toxoplasmosis parasite become less fearful of cats, sometimes even seeking out
their urine-marked areas. This behavior often leads to them being eaten by
cats. The parasite then reproduces within the body of the cat. There is
evidence that the parasite concentrates itself in the amygdala of infected rats.
Fear of death
Psychologists
have addressed the hypothesis that fear of death motivates religious
commitment, and that it may be alleviated by assurances about an afterlife.
Empirical research on this topic has been equivocal. According to Kahoe and
Dunn, people who are most firm in their faith and attend religious services
weekly are the least afraid of dying. People who hold a loose religious faith
are the most anxious, and people who are not religious are intermediate in
their fear of death. A survey of people in various Christian denominations
showed a positive correlation between fear of death and dogmatic adherence to
religious doctrine. In other words, Christian fundamentalism and other strict
interpretations of the Bible are associated with greater fear of death.
Furthermore, some religious orientations were more effective than others in
allaying that fear.
In
another study, data from a sample of white, Christian men and women were used
to test the hypothesis that traditional, church-centered religiousness and
de-institutionalized spiritual seeking are distinct ways of approaching fear of
death in old age. Both religiousness and spirituality were related to positive
psychosocial functioning, but only church-centered religiousness protected
subjects against the fear of death.
Fear
of death is also known as death anxiety. This may be a more accurate label
because, like other anxieties, the emotional state in question is long lasting
and not typically linked to a specific stimulus. The analysis of fear of death,
death anxiety, and concerns over mortality is an important feature of
existentialism and terror management theory.