Which defense mechanism is characterized by behavior that opposes one's true feelings?

The behavior characterized by opposing one's true feelings is known as reaction formation. This defense mechanism involves expressing emotions and attitudes that are the opposite of one's actual feelings, often to mask or counteract those true emotions. For instance, an individual who harbors feelings of anger or hostility may treat the person they feel negatively toward with excessive kindness and friendliness. This outward behavior serves as a protective shield against anxiety or discomfort associated with the underlying emotions.

In contrast, denial involves refusing to accept reality or confronting unpleasant facts, while suppression is a conscious effort to push unpleasant thoughts or feelings out of immediate awareness. Projection is another mechanism where individuals attribute their own unacceptable feelings or thoughts to someone else. Thus, reaction formation distinctly reflects a behavior that is consciously adopted in direct contradiction to what a person truly feels.