Circle of security a parent education and psychotherapy intervention developed by Glen Cooper, Kent Hoffman, Robert Marvin, and Bert Powell was designed to shift problematic or 'at risk' patterns of attachment–caregiving interactions to a more appropriate developmental pathway. It is stated that it is explicitly based on contemporary attachment and congruent developmental theories. Its core constructs are Ainsworth’s ideas of a Secure Base and a Haven of Safety (Ainsworth et al 1978). The aim of the protocol is to present these ideas to the parents in a ‘user friendly’, common-sense fashion that they can understand both cognitively and emotionally. This is done by a graphic representation of the child's needs and attachment system in circle form, summarizing the child's needs and the safe haven provided by the caregiver. The protocol has so far been aimed at and tested on preschoolers up to the age of 5 years.
The COS paradigm describes that the aim of the therapy as:
- 1 to increase the caregivers sensitivity and appropriate responsiveness to the child’s signals relevant to its moving away from to explore, and its moving back for comfort and soothing;
- 2 to increase their ability to reflect on their own and the child’s behavior, thoughts and feelings regarding their attachment–caregiving interactions; and
- 3 to reflect on experiences in their own histories that affect their current caregiving patterns. This latter point aims to address the miscuing defensive strategies of the caregiver.
Its four core principles are: that the quality of the child parent attachment plays a significant role in the life trajectory of the child, that lasting change results from parents changing their caregiving patterns rather than by learning techniques to manage their child's behaviors, that parents relationship capacities are best enhanced if they themselves are operating within a secure base relationship and that interventions designed designed to enhance the quality of child-parent attachments will be especially effective if they are focussed on the caregiver and based on the strengths and difficulties of each caregiver/child dyad.
There is an initial assessment which utilizes the 'Strange Situation' procedure, (Ainsworth 1978), observations, a videotaped interview using the Parent Development Interview (Aber et al 1989) and the Adult Attachment Interview (George et. al. 1984) and caregiver questionnaires regarding the child. The child's attachment pattern is classified using either Ainsworth or the PAC (Preschool Attachment Classification System). The therapy is then 'individualized' according to each dyads attachment/caregiver pattern. The program, which takes place weekly over 20 weeks, consists of group sessions, video feedback vignettes and psycho-educational and therapeutic discussions. Caregivers learn, understand and then practice observational and inferential skills regarding their children's attachment behaviors and their own caregiving responses.
Circle of Security is being field tested within the 'Head Start'/'Early Head Start' program in the USA. According to the developers the goal of the project is to develop a theory- and evidence-based intervention protocol that can be used in a partnership between professionals trained in scientifically based attachment procedures, and appropriately trained community-based practitioners. It is reported that preliminary results of data analysis of 75 dyads suggest a significant shift from disordered to ordered patterns, and increases in classifications of secure attachment. Hoffman, K.T. and Marvin, R.S. (2006) Changing Toddlers’ and Preschoolers’ Attachment Classifications: The Circle of Security Intervention. Journal of Consulting and Clinical Psychology, 74, 1017-1026. http://dx.doi.org/10.1037/0022-006X.74.6.1017
- Marvin, R., Cooper, G., Hoffman, K. and Powell, B. "The Circle of Security project: Attachment-based intervention with caregiver–pre-school child dyads". Attachment & Human Development Vol 4 No 1 April 2002 107–124 
- Cooper, G., Hoffman, K., Powell, B. and Marvin, R. "The Circle of Security Intervention; differential diagnosis and differential treatment. In "Enhancing Early Attachments; Theory, research, intervention, and policy". Edited by Berlin, L.J., Ziv, Y., Amaya-Jackson, L. and Greenberg, M.T. The Guilford press. Duke series in Child Development and Public Policy. pp 127 - 151
A brief animated version of the Circle can be found at https://www.youtube.com/watch?v=1wpz8m0BFM8