Children’s Motivation Undermined by Reward

Topic: How reward influence motivation
Researchers: Mark Lepper (Professor of Psychology at Stanford University, US), David Greene, and Robert Nisbett
Published At: Journal of Personality and Social Psychology
Year: 1973
Main Conclusion: The introduction of external reward undermines intrinsic motivation.

Description of Experiment
a. Researchers watched preschool children (age 3-5) for several days and identified those who chose to spend their free-time drawing.
b. These children were divided into 3 groups:
Group A. was offered a “Good Player” certificate with a blue ribbon carrying the child’s name, if they chose to draw.
Group B. was offered to draw; if they decided to draw, they received at the end of the session the same trophy (but without the promise of a reward ahead of time).
Group C. was simply offered to draw, without any reward.
c. Two weeks later, following the experiment above, children were offered papers and markers during their free-time – while Group B. and C. spent as much time drawing, and with the same relish as before, Group A. children spent much less time drawing.

Conclusions & Discussion
The study, and later studies with children and adults, confirmed what is called the “over justification effect”.  This effect occurs when an external incentive such as money or prizes decreases a person’s intrinsic motivation to perform a task.
The most detailed explanation for the “over justification effect” is cognitive evaluation theory.  This theory proposes that tangible rewards (like money) are perceived as controlling or coercive, and act to decrease perceived self-determination and undermine intrinsic motivation. Because unexpected tangible rewards do not motivate behavior during a task, they are less likely to be perceived as controlling, and thus less likely to undermine intrinsic motivation. Informational rewards (note the difference between “prize” and “praise”) increase perceived self-determination and feelings of competence, and consequently tend to enhance intrinsic motivation.
See also: http://en.wikipedia.org/wiki/Overjustification_effect