Emotional boundaries are the barriers that separates an individual's thoughts and feelings from those of other people. An example of setting emotional boundaries includes not taking responsibility for another person's feelings.

Boundary theory is the theory of social classification which suggests that people construct physical and mental boundaries to separate work roles from family roles and to ease the frequency of transition between these roles.

“An unclear perception of who is in and who is out of the family, created by having a family member “Present” Physically but not psychologically or present psychologically but not physically.”

"Every system has ways of including and excluding elements so that the line between those within the system and those outside of the system is clear to all. If a family is permeable and vague boundaries it is considered “open.” Open boundary systems allows elements and situations outside the family to influence it. It may even welcome external influences. Closed boundary systems isolate its members from the environment and seems isolated and self-contained. No family system is completely closed or completely open."