ABSTRACT
Existing financial behavior theories inadequately explain decision-making in culturally diverse families because they neglect how intersecting systems of power fundamentally shape psychological constructs. This article introduces the Intersectional Theory of Planned Behavior (I-TPB), transforming the Theory of Planned Behavior’s core constructs—attitudes, norms, and perceived behavioral control—from universal psychological mechanisms into intersectionally constituted phenomena. Building on TPB’s explanatory power while addressing its structural limitations, I-TPB theorizes financial behavior through three interlocking mechanisms: positional conditioning, relational contingency, and structural embedding. The proposed framework generates six theoretical propositions explaining systematic behavioral variations across intersectional positions, reframing behaviors deemed irrational under traditional TPB as structurally coherent responses rather than individual deficits. Theoretical applications across three diverse family cases demonstrate this intersectional behavioral coherence, showing how apparent inconsistencies reflect adaptive responses to documented institutional barriers. I-TPB offers a theoretically integrated framework for understanding financial behavior across diverse family structures that centers structural equity rather than individual pathology, advancing justice-oriented family science.