Relating to the Self: A Relational Frame Theory (RFT) Analysis of Change Processes in Internal Family Systems (IFS) Therapy

Internal Family Systems (IFS) therapy lacks a mechanistic explanation of how and why change occurs. This paper applies Relational Frame Theory (RFT), the behavioral-analytic framework underlying Acceptance and Commitment Therapy (ACT), as an explanatory lens for IFS change processes. We argue that blending, unblending, witnessing, and unburdening are interpretable as configurations of derived relational responding, deictic framing, and contextual control over verbal stimulus functions. The analysis reveals structural convergence between IFS and ACT at the level of mechanism, with direct relevance for child and family behavior therapists given IFS’s family systems origins and the developmental trajectory of relational framing.