Kahnemann and Tversky
    on reward, punishment,
    and regression toward the mean

Why trainers think that punishment is more effective than reward in shaping behavior.

In a discussion of flight training, experienced instructors noted that praise for an exceptionally smooth landing is typically followed by a poorer landing on the next try, while harsh criticism after a rough landing is usually followed by an improvement on the next try. The instructors concluded that verbal rewards are detrimental to learning, while verbal punishments are beneficial, contrary to accepted psychological doctrine.

This conclusion is unwarranted because of the presence of regression to the mean. As in other cases of repeated examination, an improvement will usually follow a poor performance, and a deterioration will usually follow an outstanding performance, even if the instructor does not respond to the trainee’s achievement on the first attempt.

Because the instructors had praised their trainees after good landings and admonished them after poor ones, they reached the erroneous and potentially harmful conclusion that punishment is more effective than reward.

Kahneman, D., and A. Tversky (1974). Judgment under uncertainty: heuristics and biases. Science 185, 1124-1131.

If I accumulate a really huge amount of good karma, can I be a social psychologist next time around? Just asking.

Update A reader reports not being able to tell whether I’m admiring K&T or making fun of them. Answer: admiring, all the way. This explanation is clever and right in a way characteristic of the best social psych.

Author: Mark Kleiman

Professor of Public Policy at the NYU Marron Institute for Urban Management and editor of the Journal of Drug Policy Analysis. Teaches about the methods of policy analysis about drug abuse control and crime control policy, working out the implications of two principles: that swift and certain sanctions don't have to be severe to be effective, and that well-designed threats usually don't have to be carried out. Books: Drugs and Drug Policy: What Everyone Needs to Know (with Jonathan Caulkins and Angela Hawken) When Brute Force Fails: How to Have Less Crime and Less Punishment (Princeton, 2009; named one of the "books of the year" by The Economist Against Excess: Drug Policy for Results (Basic, 1993) Marijuana: Costs of Abuse, Costs of Control (Greenwood, 1989) UCLA Homepage Curriculum Vitae Contact: Markarkleiman-at-gmail.com