Research – Circle of Security International


The Circle of Security Model and Attachment


esearch on both the Circle of Security-Intensive model and the Circle of Security Parenting program has been building over time. The first major peer-reviewed publication on the effectiveness of the COS-Intensive model was published in 2006:

Hoffman, K., Marvin, R., Cooper, G. & Powell, B. (2006). Changing toddlers' and preschoolers' attachment classifications: The Circle of Security Intervention. Journal of Consulting and Clinical Psychology, 74, 1017-1026.

The study sample consisted of parents or primary caregivers of children enrolled in Head Start programs in the state of Washington, USA. Each dyad went through a comprehensive pre-intervention evaluation which included the Strange Situation Procedure (SSP), a well-known standardized videotaped protocol. After completing COS-Intensive intervention, the parent-child dyads were once again evaluated using the Strange Situation Procedure. Trained coders, who were unaware of whether they were viewing a pre- or post-intervention SSP and who showed high levels of inter-rater agreement, identified dyads as secure, insecure and/or disorganized/insecure-other using established classification protocols. Results revealed statistically significant shifts in the percentage of dyads coded as insecure and/or disorganized after intervention as graphically depicted here:

Disorganized Attachment Status

Infographic showing disorganized attachment status with sixty percent pre-intervention and twenty-five percent post-intervention

Insecure Attachment Status

Infographic showing insecure attachment status with eighty percent pre-intervention and forty-six percent post-intervention

Because the COS-Intensive model required very intensive training and supervision, its dissemination was slow. Nevertheless, further studies followed and, when the more scalable Circle of Security Parenting program was released in 2010, more providers were trained and more research studies ensued.