Georg H. Eifert, Ph.D., is professor and chair of the department of psychology at Chapman University in Orange, CA. He was ranked among the top thirty researchers in behavior analysis and therapy in the 1990s, and he has authored over 100 publications on psychological causes and treatments of anxiety and other emotional disorders. He is a clinical fellow of the Behavior Therapy and Research Society, a member of numerous national and international psychological associations, and he serves on several editorial boards of leading clinical psychology journals. He is also a licensed clinical psychologist. He is a senior editor of the ACT book series with New Harbinger, and co-author of Acceptance and Commitment Therapy for Anxiety Disorders: A Practitioner's Guide, ACT on Life, Not on Anger, and The Mindfulness and Acceptance Workbook for Anxiety: A Guide to Breaking Free From Anxiety, Phobias, and Worry Using Acceptance and Commitment Therapy.