Final answer:
Defense mechanisms are unconscious behaviors to reduce anxiety, such as symbolization, which transforms repressed thoughts into symbols in dreams.
Step-by-step explanation:
Defense mechanisms are unconscious protective behaviors that the ego uses to reduce anxiety and protect itself from the conflicts between the id and superego. One example of a defense mechanism is symbolization, where a repressed or unconscious thought is transformed into a harmless symbol that appears in dreams. For instance, dreaming about locking doors multiple times may symbolize a desire for security or control in some aspect of one's life. This is an alternative to confronting the anxiety associated with acknowledging such a desire directly. Other defense mechanisms include reaction formation, regression, projection, and repression. They operate by distorting reality in various ways to mitigate feelings of anxiety without our conscious awareness.