Nathan H. Azrin (1930-2013) was a behavioral modification researcher, psychologist, and university professor. He taught at Southern Illinois University and was the research director of Anna State Hospital between 1958 and 1980. In 1980 he became a professor at Nova Southeastern University, and entered emeritus status at the university in 2010. Azrin was the founder of several research methodologies, including Token Economics, the Community Reinforcement Approach, Family Behavior Therapy, and habit reversal training.