Download Article


Cite as: Riordan, J. P., Blakeslee, A., & Levine, P. A. (2019). Attachmemt 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


Attachment Focused-Somatic Experiencing®

Secure Phylogenetic Attachment, Dyadic Trauma, and Completion Across the Life Cycle


Joseph P. Riordan, Abi Blakeslee, and Peter A. Levine



Trauma is transposed in the interpersonal neurobiological social dynamics of attachment and may be contagious throughout the life cycle. Trauma and social isolation may be responsible for the alarming widespread changes in human attachment dynamics. Secure attachment may be humanity’s most important survival response.
Redefining “secure attachment” to accommodate the dramatic changes in human relationships due to trauma has led to the concept of secure phylogenetic attachment (SPA). Resolving trauma with somatic experiencing (SE) (Levine, 2010) and attachment focused-somatic experiencing (AF-SE) invites the hypothesis that secure phylogenetic attachment is the antithesis of trauma.
Phylogenetics refers to the evolutionary history of relationships between individuals in a species for survival. Human relationships are facing challenges that threaten secure phylogenetic attachment and promote social isolation that may have catastrophic impact on the social evolution of the human species.
Secure phylogenetic attachment refers to evolutionary dyadic survival imperatives of psychoneurotraumatology, the innate capacity to form secure attachments throughout the life cycle. The concept of SPA incorporates neurobiological, neurochemical, behavioral, and affective interpersonal dynamics that promote attuned, connected and engaged attachment between individuals for survival throughout the life cycle.
Regarding the interpersonal neurobiological dynamics of attachment, secure phylogenetic attachment promotes dyadic synergy that is resonant, attuned, engaged, and mutually regulating. SPA invites social dynamics that involve nurturing, support, acceptance, regard, tolerance, love, and respect.
Secure phylogenetic attachment refers also to the evolution of attachment dynamics in a dyad from post-partum infant/maternal regulation through to end-of-life caregiving.
Behaviorally, SPA involves face-to-face, heart-to-heart connection in mutual soothing that promotes interpersonal connectedness and evolutionary survival of the individual, the dyad and the human species. Neurochemically, SPA involves biological processes of trauma recovery as evidenced in neurochemical shifts from cortisol (stress hormone) to oxytocin (love and bonding hormone). Further, SPA promotes an internal neurophysiological balance between parasympathetic relaxation and sympathetic excitation in the autonomic nervous system.
The authors hypothesize that there is a correlation between trauma, attachment perturbation, social isolation, and escalating psychopathology in our communities. Trauma disrupts secure phylogenetic attachment through patterns of relational dysregulation (Schore, 2012) that in turn generates dyadic trauma (Riordan, Blakeslee, & Levine, 2017). Dyadic trauma contributes to widespread loneliness and social isolation that can be resolved with dyadic completion (Riordan et al., 2017).
SE has utility and efficacy in the treatment of trauma within the individual nervous system (Brom et al., 2017; Leitch, 2007; Leitch, Vamslyke, & Allen, 2007; Parker, Doctor, & Selvam, 2008). SE works directly with implicit or nonconscious memory and is particularly effective with preverbal infants as well as for accessing preverbal memory imprints in older children and adults. SE works inherently with attachment; however, in this paper the authors combine SE with modern attachment theory and emerging neurological paradigms of traumatology. It will frame somatic psychotherapy in an AF-SE approach.
AF-SE offers neurobiological coordinates and a therapeutic process to address dyadic trauma. It uses interpersonal constructs to understand threat recovery and its role in resolving trauma with dyadic completion. This paper will introduce an AF-SE therapeutic sequence to promote the treatment of dyadic trauma with dyadic completion.

Author Note

Joseph P. Riordan, SEP, CCLP, MAPS, is Director and Principal Psychologist at Riordan Psychological Services, Jimboomba, Queensland, Australia.
Dr. Abi Blakeslee, SEP, CMT, MFT, is faculty at the Somatic Experiencing Trauma Institute and Foundation for Human Enrichment and legacy faculty at Ergos Institute for Somatic Education.
Dr. Peter A. Levine is the originator of Somatic Experiencing® and the director of the Somatic Experiencing Trauma Institute.


Correspondence concerning this article should be addressed to Joseph P. Riordan, Riordan Psychological Services. Ph. +61 7 5546 9683/+61 402 242 663 Email