Final answer:
The ego defense mechanism that involves unconsciously blocking unacceptable thoughts is known as repression. It is an unconscious process that distorts reality to reduce anxiety, often keeping disturbing thoughts from conscious awareness.
Step-by-step explanation:
An unconscious blocking of unacceptable thoughts, feelings, and impulses describes the ego defense mechanism known as repression. When confronted with anxiety, the ego resorts to unconscious strivings to protect itself from being overwhelmed. These defense mechanisms operate in various ways that distort reality.
According to Freud, the use of ego defense mechanisms is a process we are unaware of, as they function to reduce anxiety by keeping disturbing thoughts out of our conscious mind. For example, when confronted with internal conflicts or unacceptable urges, an individual may unconsciously repress those thoughts, leading to the possibility of those repressed memories causing symptoms in other areas.
Other ego defense mechanisms include reaction formation, where individuals express the opposite of their actual impulses, and regression, in which individuals revert to an earlier stage of development in their behavior.