Locus of Control

Locus of control, made popular by Julian Rotter in the 1960’s, refers to individuals’
perceptions of whether they have control over what happens to
them across situations. This personality construct has been related to the development
of depression. Specifically, it is believed that individuals who attribute
failures to internal factors (self-blame) and successes to external factors
(to other people or to luck) are more susceptible to developing feelings
of helplessness, often followed by despair and depression. Locus of control
also is hypothesized to have implications in the management of chronic
health-related problems.

In oversimplified categorizations, individuals are labeled to have an “internal”
or “external” locus of control. “External” individuals, who believe
they have little control over what happens to them, are said to be more reactive
to threat, more emotionally labile, more hostile, and lower in self-esteem
and self-control. Psychophysiological assessment studies have revealed
heart-rate acceleration and longer electrodermal habituation for “externals”
in response to the presentation of tones under passive conditions.
When faced with no-control conditions in stress situations such as inescapable
shock, “internals” show elevated physiological arousal, while findings
for “externals” are mixed. Thus, the locus of control has varying effects on
physiology, depending on the circumstances. Such effects may play a role in
psychological disorders such as depression and anxiety. Heightened physiological
reactivity may also inhibit recovery from acute illness or affect the
course of chronic health problems such as hypertension.

In addition to the relevance of personality to physiological reactivity and
psychopathology, research has demonstrated that certain personality types
may be risk factors or serve protective functions with regard to physical
health. Type A behavior pattern and hardiness are two examples. Type A behavior
pattern is characterized by competitiveness, time urgency, and hostility.
It has been identified as a potential risk factor for the development of
coronary heart disease. Psychophysiological studies have suggested that, under
certain laboratory conditions, males who exhibit the Type A pattern are
more cardiovascularly responsive. This reactivity is the proposed mechanism by which Type A behavior affects the heart. More recent research has
suggested that not all components of the Type A pattern are significantly associated
with heightened cardiovascular reactivity. Hostility seems to be the
most critical factor in determining heightened reactivity. Males who respond
to stress with hostility tend to show greater heart-rate and blood-pressure
increases than individuals low in hostility. Some research suggests that
hostility is also a risk factor for heart disease in women.
In contrast to hostility, hardiness is proposed to buffer the effects of stress
on physiology. Hardy individuals respond to stressors as challenges and believe
that they have control over the impact of stressors. They also feel commitment
to their life, including work and family. Psychophysiological studies
have supported the buffering effect of hardiness. Individuals who are
more hardy tend to be less physiologically responsive to stressors and to recover
from stressors more rapidly. Again, the construct of hardiness seems
to be more relevant for males, partially because males have been studied
more often.

These studies show that various personality types can be distinguished to
varying degrees by psychophysiological measurement. The implications of
such findings include possible physiological contributions to the development
of various psychological problems as well as personality contributions
to the development or course of physical disease.