Who was Walter Mischel?

After finishing his doctorate, Mischel began a long career in American academia. He taught at the University of Colorado from 1956 to 1958, then moved to Harvard University, where he remained until 1962. From 1962 to 1983 he was on the faculty at Stanford University, a period during which much of his most influential research took shape. In 1983 he joined Columbia University, where he stayed for the rest of his career, eventually holding the title of Robert Johnston Niven Professor of Humane Letters in the Department of Psychology.

Over the decades Mischel accumulated significant recognition within his field. He was elected to the American Academy of Arts and Sciences in 1991 and to the National Academy of Sciences in 2004. In 2007 he was elected president of the Association for Psychological Science. He also served as editor of the journal Psychological Review and held presidencies of the American Psychological Association's Division of Social and Personality Psychology and of the Association for Research in Personality. His honors included distinguished scientist awards from several major psychological societies and, in 2011, the University of Louisville's Grawemeyer Award in Psychology for his work on self-control.

In 1968 Mischel published Personality and Assessment, a book that unsettled the field of personality psychology. Building on a problem in trait assessment first raised by Gordon Allport in 1937, Mischel showed that empirical studies frequently failed to support a core assumption of personality theory: that a person's behavior related to a given trait, such as conscientiousness or sociability, stays consistent across different situations. Instead, he argued that behavior depends heavily on the specific situation a person is in, and that the common belief in stable, cross-situational personality traits was largely a myth.

Rather than dismissing personality consistency altogether, Mischel proposed that psychologists had been looking for it in the wrong place. He suggested that if researchers incorporated how individuals perceived their situations, and examined behavior within that context, genuine patterns of individual consistency would emerge. He described these patterns as situation-behavior signatures, distinctive if-then relationships such as a person behaving one way under one type of circumstance and differently under another. Later observational research on social behavior supported this idea, showing that people with similar average levels of a behavior, such as aggression, nonetheless displayed that behavior in strikingly different and predictable patterns depending on the situation.

Beginning in the late 1960s and early 1970s, Mischel turned his attention to how people, especially children, manage self-control in the face of tempting immediate rewards. His best-known studies, conducted with preschoolers, became known as the marshmallow experiments. A child was offered a choice: eat one treat right away, or wait roughly ten minutes to receive two treats instead. The treat used was not always a marshmallow; Oreo cookies and M&Ms also served the same purpose in different versions of the test.

Mischel followed up with many of these children's families years later and found notable links between a child's ability to delay gratification and later life outcomes. Children who struggled to wait tended to show higher rates of obesity and lower academic achievement as they grew older, while those who waited longer tended to have lower body mass index and higher standardized test scores. He also observed a stark difference between children raised below the poverty line and those with college-educated parents, with low-income children far more likely to take the immediate treat.

Mischel continued following his original participants over subsequent decades, linking their early capacity for delay with outcomes such as SAT scores, social and cognitive competence, educational attainment, and drug use. This research also opened up broader study into temporal discounting in decision-making and into the cognitive and emotional mechanisms behind self-control. Later work led Mischel to consider the marshmallow test partly as a test of trust: children raised by absent parents were sometimes less likely to wait, possibly because they doubted the promise of a larger reward. He also pointed to the role of positive expectations and goal-directed belief in explaining why some children were able to wait while others were not.

Mischel's work eventually reached audiences well beyond academic psychology. In 2014 he published The Marshmallow Test, his first book intended for general readers, and appeared on The Colbert Report that September to discuss it. His research was also the subject of an extensive interview on the PBS NewsHour's Making Sen$e website in October 2014, followed by two segments on the PBS NewsHour broadcast in January 2015. In 2016 he was interviewed for the NPR podcast Invisibilia, discussing how personality operates and how it can shift when circumstances change.

Mischel lived in Manhattan, where he enjoyed painting and travel. He spoke several languages, including English and French, and spent time regularly in Paris as well as later visits to Bend, Oregon. He had three children and six grandchildren. He died at his home in New York from pancreatic cancer on September 12, 2018, at the age of 88.