Bert Powell, MA, began his clinical work as an outpatient family therapist in a community mental health center, where he helped a broad range of families find and use unacknowledged strengths to address their problems. Mr. Powell is certified in psychoanalytic psychotherapy by The Masterson Institute in New York City. He is Adjunct Assistant Professor in the Graduate School of Counseling Psychology at Gonzaga University and serves as an International Advisor to the editorial board of the Journal of Attachment and Human Development. Since 1985, he has had a shared clinical practice in Spokane, Washington, with Kent Hoffman and Glen Cooper. Much of their work has focused on the creation and dissemination of the Circle of Security, for which each has received the Washington Governor’s Award for Innovation in Child Abuse Prevention and the New York Attachment Consortium's Bowlby–Ainsworth Award, among other honors. They are coauthors of The Circle of Security Intervention (for mental health professionals) and Raising a Secure Child: How Circle of Security Parenting Can Help You Nurture Your Child's Attachment, Emotional Resilience, and Freedom to Explore (for parents).

Glen Cooper, MA, has worked as a psychotherapist with individuals and families in both agency and private practice settings since the 1970s. He has extensive training in family systems, object relations, attachment theory, and infant mental health assessment. Mr. Cooper also works as a treatment foster parent and long-time Head Start consultant. Since 1985, he has had a shared clinical practice in Spokane, Washington, with Kent Hoffman and Bert Powell. Much of their work has focused on the creation and dissemination of the Circle of Security, for which each has received the Washington Governor’s Award for Innovation in Child Abuse Prevention and the New York Attachment Consortium's Bowlby–Ainsworth Award, among other honors. They are coauthors of The Circle of Security Intervention (for mental health professionals) and Raising a Secure Child: How Circle of Security Parenting Can Help You Nurture Your Child's Attachment, Emotional Resilience, and Freedom to Explore (for parents).

Kent Hoffman, RelD, has been a psychotherapist since 1972. Certified in psychoanalytic psychotherapy by The Masterson Institute in New York City, he has worked with prison and homeless populations as well as adults seeking psychoanalytic psychotherapy. His primary focus since the 1990s has been working with and designing treatment interventions for street-dependent teens with young children. The underlying theme of his life work can be found in a TEDx talk titled "Infinite Worth." Since 1985, Dr. Hoffman has had a shared clinical practice in Spokane, Washington, with Glen Cooper and Bert Powell. Together, they have created and disseminated the Circle of Security, for which each has received the Washington Governor’s Award for Innovation in Child Abuse Prevention and the New York Attachment Consortium's Bowlby–Ainsworth Award, among other honors. They are coauthors of The Circle of Security Intervention (for mental health professionals) and Raising a Secure Child: How Circle of Security Parenting Can Help You Nurture Your Child's Attachment, Emotional Resilience, and Freedom to Explore (for parents).

Bob Marvin, PhD, served as principal investigator on the original COS study and participated in the development of COS. He is Director of the Mary Ainsworth Attachment Clinic in Charlottesville, Virginia. With Bert Powell, Glenn Cooper, and Kent Hoffman, Dr. Marvin is a corecipient of the Bowlby–Ainsworth Award, presented by the New York Attachment Consortium, for developing and implementing COS.