Stan Tatkin, PsyD, MFT, is a clinician, researcher, teacher, and developer of A Psychobiological Approach to Couple Therapy (PACT). PACT is a polytheoretical, non-linear approach to dyadic systems that integrates developmental neuroscience, arousal regulation, and attachment theory. Psychobiology centers on early attachment and its effect on the developing brain and autonomic nervous system. PACT encourages partners to adopt secure-functioning principles of behavior apart from their actual attachment organization.