The Bowen family systems theory and the Minuchin conceptual model of structural family therapy are two models that examine dysfunctional youth and dysfunctional families as units in which influence and effect travel in dyad patterns (one person to another person) and in triangulated patterns, which is a dyad that deflects anxiety and discord off onto a by-stander third person in the family group, forming a triangulation.
Minuchin realized that helping psychologically struggling youth was ineffectual without placing the youth within the dynamic of their family unit. As a result, he worked with the entire family, not just the youth. He also realized the extent of social and cultural influence and effect on the family unit, and that social and cultural impact played a significant role in the development of dysfunction in individual youths as well as in the entire family unit. Minuchin and his associates carried his theories to the streets by training people in dysfunctional geo-social settings to act as family counselors. One of Minuchins most significant contributions was the concept of rigid or diffuse inter-personal boundaries. Inter-personal boundaries exist on a continuum, and the degree of rigidity or diffusness governs the relationships and interactions family individuals and subgroups have with each other, the ideal being a functionally fluid balance between diffuse boundaries and rigid boundaries.
Bowen's theory provides an extensive model for the ways in which dysfunctional families defuse anxiety they are failing to cope with in productive ways. Critical to Bowen's ideas about the defusing anxiety are triangulation (pulling in a third person as the "scapegoat") and sibling birth position (eldest, middle and last child positions). Also central to Bowen's theory is the concept of differentiated self and the undifferentiated self. An undifferentiated self is unable to feel and think independently of the family system of emotional processes. A differentiated self is able to disagree with the family system while still embracing the family and being embraced by the family regardless of differences in thoughts, decisions or feelings.