The Circle of Security intervention uses a group treatment modality to provide parent education and
psychotherapy that is based on attachment theory. The purpose of this study was to track changes in
children’s attachment classifications pre- and immediately postintervention. Participants were 65
toddler– or preschooler– caregiver dyads recruited from Head Start and Early Head Start programs. As
predicted, there were significant within-subject changes from disorganized to organized attachment
classifications, with a majority changing to the secure classification. In addition, only 1 of the 13
preintervention securely attached children shifted to an insecure classification. Results suggest that the
Circle of Security protocol is a promising intervention for the reduction of disorganized and insecure
attachment in high-risk toddlers and preschoolers.