Psychologists study the human mind and human behavior. Research psychologists investigate the physical, cognitive, emotional, or social aspects of human behavior. Psychologists in applied fields provide mental health care in hospitals, clinics, schools, or private settings.Psychologists apply their knowledge to a wide range of endeavors, including health and human services, computer science, management, education, law, and sports. In addition to a variety of work settings, psychologists may specialize in a number of different areas. Clinical and counseling psychologists work in counseling centers, independent or group practices, hospitals, or clinics helping mentally and emotionally disturbed clients adjust to life, or helping medical and surgical patients deal with illnesses or injuries. Other fields in psychology include health, brain, counseling, school, and organizational and developmental psychology. Typically, a Master's degree or Ph.D.is required to pursue a professional career. Employment may be found in clinics, social service agencies, business and industry, schools and universities, hospitals, corrections, human resources, and government services. Many psychologists are self-employed in private practice.