Psychologist Edward L. Deci, Self-Determination Pioneer, Dies at 83

His work with Richard Ryan changed how psychologists understand human motivation and what people need to thrive.

Published on Feb. 26, 2026

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Edward L. Deci, a psychologist at the University of Rochester whose groundbreaking insights, with his colleague Richard M. Ryan, into what motivates people to do what they do — or not — helped revolutionize fields as disparate as the workplace, education, sports and marketing, died on Feb. 14 at his home in Rochester, N.Y. He was 83. Deci and Ryan developed self-determination theory, which posits that people are naturally curious and eager to grow, and that they flourish in situations in which they feel autonomous, connected and competent.

Why it matters

Deci and Ryan's work challenged the prevailing behaviorist approach in psychology, which viewed motivation as a single force of external carrots and sticks. Their theory that different types of motivation are key has become foundational to modern industrial relations, teacher training and the self-help movement.

The details

In experiments in 1971, Deci found that introducing external rewards for inherently interesting tasks diminished the students' internal motivation to complete them. This became a core element of self-determination theory. Deci and Ryan argued that there are three core human needs - autonomy, competence and relatedness to others - and that only when those are met can people feel a true sense of autonomous motivation.

  • Deci and Ryan started the Human Motivation Program at the University of Rochester in 1981.
  • They published 'Intrinsic Motivation and Self-Determination in Human Behavior' in 1985.
  • Deci retired from the University of Rochester in 2017.

The players

Edward L. Deci

A psychologist at the University of Rochester whose groundbreaking work with Richard M. Ryan on self-determination theory revolutionized fields like the workplace, education, sports and marketing.

Richard M. Ryan

Deci's colleague at the University of Rochester who co-developed self-determination theory with him.

Brett Jensen

Deci's nephew who said the cause of Deci's death was complications of dementia.

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What they’re saying

“When we began to reward people for things they found interesting, they stopped finding it interesting anymore. This activity, which they used to find interesting and enjoyable, now they find it a route to getting the reward.”

— Edward L. Deci (2011 video)

“Legitimize your child's feeling about the activity, whatever that feeling might be. If you try to convince children that something is interesting when it isn't, you're saying that their feelings don't count.”

— Edward L. Deci (The New York Times, 1990)

The takeaway

Deci and Ryan's self-determination theory, which emphasizes the importance of autonomy, competence and relatedness in human motivation, has become a foundational concept in modern psychology, with wide-ranging implications for fields like education, business and personal development.