Zaslow and his "Z-process", a physically rough version of holding therapy, influenced Foster Cline (known as the "father of attachment therapy") and associates at his clinic in Evergreen A key tenet of Zaslow's approach was the notion of "breaking through" a child's defenses—based on the model of ego defenses borrowed from psychoanalytic theory, which critics state has been misapplied. The "breaking through" metaphor was then applied to children whose attachments were thought to be impaired. The clinic, originally called the Youth Behavior Program, was subsequently renamed the Attachment Center at Evergreen.