History of Ethics in Psychology By Rodney Winklevoss 6500 BCE Trephination Period: 1932 to 1972 Tuskegee Syphillis Study 1938 B.F Skinner Operant Conditioning Period: 1945 to 1946 Nuremberg Code 1947 APA Committee on Ethical Standards for Psychologist 1964 Stanley Milgram Obedience testing 1971 Zambardo Prison Experiment