Attachment Focused-Somatic Experiencing: Secure Phylogenetic Attachment, Dyadic Trauma, and Completion Across the Life Cycle
May 13, 2026
About This Publication
What if trauma doesn't just live in the individual — but spreads through our closest relationships, quietly reshaping the way we connect and attach throughout our lives?
This peer-reviewed paper, co-authored by Dr. Abi Blakeslee alongside Joseph P. Riordan and Dr. Peter A. Levine, explores exactly that. Published in the International Journal of Neuropsychotherapy (Volume 7, Issue 3, 2019), it introduces a framework for understanding how trauma disrupts attachment — and how Attachment Focused-Somatic Experiencing (AF-SE) can restore it.
View and Read the Full Research
What This Paper Explores
The paper centers on Secure Phylogenetic Attachment (SPA) — our deepest evolutionary drive to form safe, attuned bonds with others. When trauma enters, it doesn't just affect the individual. It disrupts the relational space between two people, generating what the authors call dyadic trauma — a contagious, neurologically disintegrating process that drives social isolation and psychopathology across the lifespan.
Through clinical vignettes spanning infancy to late adulthood, the authors demonstrate how dyadic completion — the restoration of secure attachment through the face–heart connection and resolution of incomplete survival responses — can be achieved with AF-SE.
Why This Matters for Clinicians
This paper bridges Polyvagal Theory, modern attachment theory, and Somatic Experiencing into a unified, sequenced treatment approach for trauma that lives not just in the body — but between bodies. Essential reading for SE practitioners and attachment-informed clinicians working with relational and developmental trauma.
Citation
Riordan, J. P., Blakeslee, A., & Levine, P. A. (2019). Attachment focused-somatic experiencing: Secure phylogenetic attachment, dyadic trauma, and completion across the life cycle. International Journal of Neuropsychotherapy, 7(3), 57–90. doi:10.12744/ijnpt.2019.057-090
About Dr. Abi Blakeslee
Dr. Abi Blakeslee, Ph.D., MFT, SEP, CMT is a trauma psychologist, Senior Faculty at Somatic Experiencing International, and founder of Implicit Psychotherapy. Her research bridges somatic psychology, neuroscience, and depth psychology to advance trauma treatment across the lifespan.
Secure Phylogenetic Attachment, Dyadic Trauma, and Completion Across the Life Cycle
by Joseph P Riordan SEP, MAPS; Abi Blakeslee SEP, CMT, MFT, Ph.D, Peter A Levine Ph.D. (2019)
International Journal of Neuropsychotherapy, 7(3). 4-90.