<Li> American Psychological Association . (1977, March). Ethical standards of psychologists . APA Monitor, 22 - 23 . (change to Principle 3: Moral and Legal Standards) </Li> <Li> American Psychological Association . (1979). Ethical standards of psychologists . Washington, DC: Author . (no change in language) </Li> <Li> American Psychological Association . (1981). Ethical principles of psychologists . American Psychologist, 36, 633 - 638 . (change to Principle 3: Moral and Legal Standards) </Li> <Li> American Psychological Association . (1990). Ethical principles of psychologists (Amended June 2, 1989). American Psychologist, 45, 390 - 395 . (no change in language) </Li>

Ethical principles developed by the american psychological association require psychologists to