We use the Human Synergistics circumplex as a key component of our coaching programmes. The circumplex was originally developed by Dr. J. Clayton Lafferty during the early 1970’s. It builds on the ideas and research of several people, including Albert Ellis, Karen Horney, Timothy Leary, Norman R.F. Maier, Abraham Maslow, David C. McClelland, Carl Rogers, and Henry Stack Sullivan, as well as Lafferty’s own work as a clinical psychologist.