What defense mechanism occurs when a person expresses an opposite emotion to what they feel?

The correct choice is reaction formation, which is a defense mechanism where an individual unconsciously replaces an unwanted or anxiety-provoking feeling with a direct opposite emotion. For instance, if a person feels angry towards someone but finds that feeling unacceptable, they might overtly display affection towards that person instead. This process helps to reduce anxiety by providing a more socially acceptable expression of emotion.

Understanding reaction formation emphasizes the complexity of human emotions and behavior, particularly how individuals navigate conflicting feelings. This mechanism can be seen in various scenarios, such as someone who feels insecure yet acts overly confident to mask their vulnerabilities. Recognizing this behavior is crucial in developmental psychology as it can influence interpersonal relationships and self-perception throughout one's life.