What term refers to the state where one uses psychological barriers to control unwanted intrusions?

The term that refers to using psychological barriers to control unwanted intrusions is best understood in the context of "reserve." In psychological and architectural discourse, reserve implies a deliberate restraint or a protective stance whereby an individual maintains a certain distance or boundary against external influences or intrusions. This concept can be related to physical spaces designed to offer privacy or security, as well as personal psychological strategies to maintain one’s mental or emotional space.

In contrast, barrier typically refers to physical objects or structures, which do not encapsulate the psychological aspect. Isolation suggests a complete separation, which may not necessarily involve an active management of intrusions. Withdrawal indicates a retreat from interaction, but again lacks the emphasis on the psychological control aspect inherent to the concept of reserve. Therefore, reserve is the most fitting term in this context as it relates specifically to the intentional act of managing and controlling one's personal space and interactions.