Mark R. Lepper (born December 5, 1944) is the Albert Ray Lang Professor of

psychology Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries betwe ...

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

, and a leading theorist in

social psychology Social psychology is the scientific study of how thoughts, feelings, and behaviors are influenced by the real or imagined presence of other people or by social norms. Social psychologists typically explain human behavior as a result of the r ...

. He is particularly known for his research on

attribution theory Attribution is a term used in psychology which deals with how individuals perceive the causes of everyday experience, as being either external or internal. Models to explain this process are called attribution theory. Psychological research into a ...

and

confirmation bias Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms or supports one's prior beliefs or values. People display this bias when they select information that supports their views, ignoring ...

, and for his collaborations with

Lee Ross Lee David Ross (August 25, 1942 – May 14, 2021) was a Canadian-American professor. He held the title of the Stanford Federal Credit Union Professor of Humanities and Sciences at Stanford University and was an influential social psychologist wh ...

Life

Lepper is primarily responsible for the elucidation of the

overjustification effect The overjustification effect occurs when an expected external incentive such as money or prizes decreases a person's intrinsic motivation to perform a task. Overjustification is an explanation for the phenomenon known as motivational "crowding out" ...

, alongside

Richard Nisbett __NOTOC__ Richard Eugene Nisbett (born June 1, 1941) is an American social psychologist and writer. He is the Theodore M. Newcomb Distinguished Professor of social psychology and co-director of the Culture and Cognition program at the University ...

. With frequent collaborator

, and

Robert Vallone The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of '' Hruod'' ( non, Hróðr) "fame, glory, honou ...

, he authored the first study to identify the hostile media effect. With Ross and

Charles Lord Charles Edwin Lord II also known as Charles E. Lord (April 26, 1928 in New York City – January 8, 1993 in Bridgeport, Connecticut) was an investment banker and appointed Vice-Chairman of the Export-Import Bank of the United States of the Un ...

he also authored an important study on

attitude change Attitudes are associated beliefs and behaviors towards some object. They are not stable, and because of the communication and behavior of other people, are subject to change by social influences, as well as by the individual's motivation to maint ...

and what is now called

disconfirmation bias Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms or supports one's prior beliefs or values. People display this bias when they select information that supports their views, ignoring ...

. With Lord he later theorized

attitude representation theory Attitude may refer to: Philosophy and psychology * Attitude (psychology), an individual's predisposed state of mind regarding a value * Metaphysics of presence * Propositional attitude, a relational mental state connecting a person to a prop ...

. He has also worked with

Thomas Gilovich Thomas Dashiff Gilovich (born January 16, 1954) an American psychologist who is the Irene Blecker Rosenfeld Professor of Psychology at Cornell University. He has conducted research in social psychology, decision making, behavioral economics, and ...

and

Merrill Carlsmith James Merrill Carlsmith (April 12, 1936 – April 19, 1984) was an American social psychologist perhaps best known for his collaboration with Leon Festinger and Elliot Aronson in the creation and development of cognitive dissonance theory. He als ...

. Lepper attended Stanford University as an undergraduate, earning a B.A. with great distinction in psychology in 1966. He subsequently earned a

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

Social Social organisms, including human(s), live collectively in interacting populations. This interaction is considered social whether they are aware of it or not, and whether the exchange is voluntary or not. Etymology The word "social" derives from ...

and

Developmental Psychology Developmental psychology is the science, scientific study of how and why humans grow, change, and adapt across the course of their lives. Originally concerned with infants and children, the field has expanded to include adolescence, adult deve ...

Yale University Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the wo ...

in 1970, returning to Stanford in 1971 as an assistant professor. Lepper became a full professor of psychology and, by courtesy, of education in 1982, and has since served as chairman of the department of psychology between 1990 and 1994, and again after 2000. He is a fellow of the

American Psychological Association The American Psychological Association (APA) is the largest scientific and professional organization of psychologists in the United States, with over 133,000 members, including scientists, educators, clinicians, consultants, and students. It ha ...

and a charter fellow of the American Psychological Society.

External links

Official site
{{DEFAULTSORT:Lepper, Mark 1944 births Living people Social psychologists Stanford University Department of Psychology faculty Fellows of the American Psychological Association