Theorists
Mark Lepper – 1944 Present
A comprehensive academic examination of Mark R. Lepper's life, seminal experiments on intrinsic motivation, hostile...
# Overjustification Effect
6 results
Experiments
The Intrinsic vs. Extrinsic Motivation Experiment (Soma Cubes) – Edward Deci
A comprehensive academic analysis of Edward Deci's 1971 Soma puzzle cube experiments, examining intrinsic motivation,...
September 17, 2026
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Dr. Mohammed Looti
Experiments
The Overjustification Effect Experiment (Magic Markers) – Mark Lepper, David Greene, and Richard Nisbett
A comprehensive academic analysis of Lepper, Greene, and Nisbett's landmark 1973 Magic Markers experiment demonstrating...
September 16, 2026
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Dr. Mohammed Looti
Experiments
The Self-Determination Theory Experiments (Intrinsic Motivation) – Edward Deci and Richard Ryan
A comprehensive academic analysis of Edward Deci and Richard Ryan's foundational experiments on intrinsic motivation...
September 16, 2026
•
Dr. Mohammed Looti
Theories
Overjustification Effect Model – Edward L. Deci & Mark R. Lepper
A comprehensive academic analysis of the Overjustification Effect Model by Edward L. Deci and Mark...
September 11, 2026
•
Dr. Mohammed Looti
Experiments
The Overjustification Effect Experiment – Mark Lepper and David Greene
A comprehensive academic analysis of the seminal 1973 overjustification effect experiment by Mark Lepper, David...
September 5, 2026
•
Dr. Mohammed Looti