Emotion is a complex, subjective experience accompanied by biological and behavioral changes. Emotion involves feeling, thinking, activation of the nervous system, physiological changes, and behavioral changes such as facial expressions.
Different theories exist regarding how and why people experience emotion. These include evolutionary theories, the James-Lange theory, the Cannon-Bard theory, Schacter and Singer’s two-factor theory, and cognitive appraisal.
Evolutionary Theories
More than a century ago, in the 1870s, Charles
Darwin proposed that emotions evolved because they had adaptive
value. For example, fear evolved because it helped people to act in ways
that enhanced their chances of survival. Darwin believed that facial
expressions of emotion are innate (hard-wired). He pointed out that facial
expressions allow people to quickly judge someone’s hostility or
friendliness and to communicate intentions to others.
Recent evolutionary theories of emotion also consider emotions to
be innate responses to stimuli. Evolutionary theorists tend to downplay the
influence of thought and learning on emotion, although they acknowledge that
both can have an effect. Evolutionary theorists believe that all human
cultures share several primary emotions, including happiness, contempt,
surprise, disgust, anger, fear, and sadness. They believe that all other
emotions result from blends and different intensities of these primary
emotions. For example, terror is a more intense form of the primary emotion
of fear.
The James-Lange Theory
In the 1880s, two theorists, psychologist William James and
physiologist Carl Lange, independently proposed an idea that
challenged commonsense beliefs about emotion. This idea, which came to be known
as the James-Lange theory, is that people experience emotion
because they perceive their bodies’ physiological responses to external events.
According to this theory, people don’t cry because they feel sad. Rather, people
feel sad because they cry, and, likewise, they feel happy because they smile.
This theory suggests that different physiological states correspond to different
experiences of emotion.
The Cannon-Bard Theory
The physiologist Walter Cannon disagreed with the James-Lange
theory, posing three main arguments against it:
