Punishment Trumps Rewards in Learning Behavior Experiment
Punishing students for poor performance may be more
effective
than rewarding them for doing well, according to a
recent study conducted by
researchers at Washington
University in St.
Louis.
In an experiment conducted with Washington University
college
students, the results appeared to suggest that punishment influences
behavior
more than rewards do. In fact, the measured impact of
losing
money tokens in the experiment was two or three times greater than
winning
money tokens.
In the experiment, one group of students was asked to
listen
to a series of clicking noises and indicate whether they heard more in
the left
or right ear. Likewise, another group was asked to watch for flashes of
light
and indicate whether they saw more on the right or left side.
The clicks and flashes were randomized and came with
varying
frequencies, making it difficult to ever guess the correct response.
Nevertheless, also at random, students were rewarded
5, 10,
15, 20 or 25 cents whenever they got a "right" answer. They were also
penalized
whenever they got a "wrong" answer.
When students got what they thought was a "right"
answer, they
were more likely to make the same choice the next time. However, much
more
frequently, they were less likely to make the same choice if they were
told
they had gotten the "wrong" answer.
Also, while the likelihood of making the same choice
again after
a "right" answer was greater when the reward was larger, the likelihood
of not
making the same choice for the "wrong" answer remained about the same,
suggesting the students took more seriously the punishment than the
reward.
This particular Washington University study, funded
by the
National Institutes of Health, was less complex than previous studies of
effects of rewards and punishments on behavior. In this study, because
the
stimulus — the clicks and flashes — were random, researchers were more
easily
able to pinpoint the effects of behavior.
"The question of how rewards and punishments
influence behavior
has occupied psychologists for over 100 years," said the lead
researcher, Jan
Kubanek, a postdoctoral research associate in anatomy and neurobiology. "The
difficulty has been devising effective tasks to probe the question. We
used a
simple approach that reveals dramatic differences in the way people
respond."
Kubanek said the results suggest that negative
feedback may be
more effective than positive feedback at affecting behavior, adding "such
feedback does not have to be harsh, since it appears that we tend to
react in
the same manner to any amount of negative feedback."
About the Author
Michael Hart is a Los Angeles-based freelance writer and the former executive editor of THE Journal.