The cultural upheavals of the 1960s saw the rise of a so-called Third Force in American education. The leading figures of the Third Force were humanist psychologists Carl Rogers and Abraham Maslow. Maslow had worked on sexological research under the auspices of Edward L. Thorndike from 1935 to 1937. Thorndike had developed the purely behaviorist teaching method of SR, stimulus-response, which reduced education to a form of animal training. But eventually Maslow rebelled against such pure behaviorism. As for his sexological research, feminist Betty Friedan believed that Maslow’s findings helped advance the feminist approach to psychology. Maslow, trained in behavioral psychology, began to moderate it with his own theory of self-actualization.