PACT vs Somatic Experiencing
A side-by-side comparison: mechanism, evidence, the conditions each treats, philosophical roots, and where they actually disagree clinically.
At a glance
PACT
- Tradition
- Attachment
- Founder
- Stan Tatkin (2009)
- Evidence
- Emerging evidence
- Focus
- Experiential + Neurobiological
- Format
- Couples
- Duration
- Short-medium
Somatic Experiencing
- Tradition
- Somatic
- Founder
- Peter Levine (1997)
- Evidence
- RCT-supported
- Focus
- Somatic + Experiential
- Format
- Individual
- Duration
- Medium-term
How they work
PACT
Core mechanism: Real-time tracking of arousal states and nonverbal cues reveals partners' attachment strategies; therapist uses psychoeducation about the nervous system and in-session experiments to shift couples from insecure to secure functioning
Ontology: Partners operate from implicit procedural memory shaped by early attachment; relationship distress reflects automatic threat responses between two nervous systems that have not learned to co-regulate
Somatic Experiencing
Core mechanism: Titrated pendulation between activation and resource states completes truncated survival responses trapped in the body
Ontology: Incomplete defensive responses (fight/flight/freeze) remain bound in the nervous system as undischarged survival energy
Conditions treated
1 shared · 1 PACT-only · 5 Somatic Experiencing-only
Both treat
Only PACT
Only Somatic Experiencing
What each assumes — and misses
PACT
Philosophical roots: Bowlby (attachment as survival system); Schore (right-brain affect regulation, developmental neuroscience); polyvagal theory (Porges); Ainsworth (Strange Situation — anxious/avoidant/disorganized maps); object relations (implicit relational knowing)
Blind spots: No controlled outcome research on PACT itself; heavy reliance on neuroscience framing may overstate what brain-based explanations can prescribe clinically; can feel confrontational when therapist tracks and names arousal patterns in real time
Therapeutic voice: Watch your partner's face right now. What do you see? What happens in your body when you see that?
Somatic Experiencing
Philosophical roots: Reich/Lowen (body holds defense — Levine studied with both); Merleau-Ponty (lived body); Darwin (survival instincts); ethology (Tinbergen, Lorenz — animal defensive responses); James-Lange (emotion as bodily process)
Blind spots: Risk of over-physiologizing psychological meaning; limited manualization makes research difficult; can be vague in application
Therapeutic voice: Where in your body do you feel that right now? Just notice, without trying to change it.
Choosing between them
PACT (Attachment) and Somatic Experiencing (Somatic) come from different traditions, which means they assume different things about what a person is, what causes suffering, and what the therapeutic relationship is for. The choice between them is often less about "which works better" and more about which set of assumptions fits the client and the therapist.
For deeper coverage: see the full PACT and Somatic Experiencing pages, or use the interactive comparison tool to add more modalities to this comparison.