Psychological term often used for observable expression of feelings, but occasionally used for privately experienced emotions.

The expressions of emotion or feelings to others include facial expressions, gestures, tone of voice, and other signs of emotion such as laughter or tears. As a child grows and develops, environmental factors, such as peer pressure, and internal factors, such as self-consciousness, help to shape the affect.

What is considered a normal range of affect—display of emotion—varies from family to family, from situation to situation, and from culture to culture. Even within a culture, a wide variation in affective display can be considered normal. Certain individuals may gesture prolifically while talking, and display dramatic facial expressions in reaction to social situations or other stimuli. Others may show little outward response to social environments, expressing only a narrow range of affect to the outside world.

Facial expressions are a key...