The parental subsystem, also know as the executive subsystem, is the foundation of any family with children. The parental subsystem can include biological, adoptive, step, and foster parents as well as others filling parental roles, such as grandparents. Ideally, the parental subsystem provides the leadership and executive decision-making for the family in ways that support healthy functioning of the system and its members. The quality of parenting and type of boundaries around the parental subsystem are the primary predictors of how well a family functions.

In healthy two-parent families, the parental subsystem is a stable alliance. The parents will disagree at times, but they typically provide a unified front and form a collaborative team to support each other with the various tasks of leading a family. The love, limits, and guidance that they provide are fair, reasonable, and age-appropriate. Although this vision for family leadership may sound Pollyannaish or pie-in-the-sky to some people, research has consistently found that a strong parental bond is a fundamental feature of well-functioning families while a poorly functioning parental subsystem is associated with a variety of psychological and behavioral problems in children, teenagers, and adults.

Single-parent families that function well also exhibit a clearly defined executive subsystem that provides leadership for the family. Although it is typical in single-parent families that some executive functions are shared with older children, friends, or extended relatives, an appropriate boundary still exists between children and adults which allows children to feel safe and secure and to know their place in the family. Children need to know that someone is in charge, there are limits to what is permissible, and their needs will be addressed and met.