Some, however, may seek additional support from licensed psychologists or psychiatrists. Propst consulted with mathematicians, behavioral psychologists, and anthropologists. Other psychologists and neuroscientists reject these arguments. It reserves the practice of psychotherapy to medical doctors, clinical psychologists and clinical orthopedagogists. Several cognitive psychologists and educators have questioned the central claims of constructivism. Evaluators usually have had training as clinical psychologists. Social Influence is an area of intense study for Social Psychologists and Communication theorists. It is used by licensed physicians, psychologists, and others. Incentive theory is promoted by behavioral psychologists, such as B.F. Skinner. The latter interests historians of esotericism, psychologists, and some philosophers and spiritualists. The method is guided by research done by a variety of applied psychologists and educators. People often think of the discipline as involving only such clinical or counseling psychologists. Problem solving, according to prominent cognitive psychologists, is fundamental to learning. This is the term used by most doctors and psychologists. The problem continues to attract the attention of cognitive psychologists.