The Yale experiment was a variation of the classic one that first demonstrated cognitive dissonance, a term coined by the social psychologist Leon Festinger. In 1956 one of his students, Jack Brehm, carted some of his own wedding gifts into the lab (it was a low-budget experiment) and asked people to rate the desirability of things like an electric sandwich press, a desk lamp, a stopwatch and a transistor radio.
Then they were given a choice between two items they considered equally attractive, and told they could take one home. (At the end of the experiment Mr. Brehm had to confess he couldn’t really afford to give them anything, causing one woman to break down in tears.) After making a choice (but before having it snatched away), they were asked to rate all the items again.
Suddenly they had a new perspective. If they had chosen the electric sandwich press over the toaster, they raised its rating and downgraded the toaster. They convinced themselves they had made by far the right choice.
So, apparently, did the children and capuchin monkeys studied at Yale by Louisa C. Egan, Laurie R. Santos and Paul Bloom. The psychologists offered the children stickers and the monkeys M&M’s.
Once a monkey was observed to show an equal preference for three colors of M&M’s — say, red, blue and green — he was given a choice between two of them. If he chose red over blue, his preference changed and he downgraded blue. When he was subsequently given a choice between blue and green, it was no longer an even contest — he was now much more likely to reject the blue.
- John Tierney, Go Ahead, Rationalize. Monkeys Do It, Too., NYT, Nov. 6, 2007
I also heard from the scientist who did that famous 1956 experiment, Jack Brehm, and he concurs with the researchers who see cognitive dissonance in the monkeys:
- It does not surprise me that monkeys behave in this way. Cognitions guide behavior for monkeys, dogs, cats, and other animals as well as humans, and frequently there will be conflicts between behavioral options. When a choice is made, one or more preferences can be thwarted, and that is the basis of dissonance. So the animal (including humans) must give up its desire for the rejected alternative.
- John Tierney, I Am, Therefore I Rationalize, NYT, Nov. 9, 2007
A methodological flaw may have led one of the central literatures in social psychology to spuriously conclude that people rationalize past choices, by failing to appreciate that those choices reflect people’s preferences.
- M. Keith Chen, Rationalization and Cognitive Dissonance:Do Choices Affect or Reflect Preferences?, 2008
How Choice Affects and Reflects Preferences: Revisiting the Free-Choice Paradigm
Keith Chen and Jane Risen
Journal of Personality and Social Psychology, October 2010
After making a choice between two objects, people evaluate their chosen item higher and their rejected item lower (i.e., they "spread" the alternatives). Since Brehm's (1956) initial free-choice experiment, psychologists have interpreted the spreading of alternatives as evidence for choice-induced attitude change. It is widely assumed to occur because choosing creates cognitive dissonance, which is then reduced through rationalization. In this paper, we express concern with this interpretation, noting that the free-choice paradigm (FCP) will produce spreading, even if people's attitudes remain unchanged. Specifically, if people's ratings/rankings are an imperfect measure of their preferences, and their choices are at least partially guided by their preferences, then the FCP will measure spreading, even if people's preferences remain perfectly stable. We show this, first, by proving a mathematical theorem that identifies a set of conditions under which the FCP will measure spreading, even absent attitude change. We then experimentally demonstrate that these conditions appear to hold, and that the FCP measures a spread of alternatives, even when this spreading cannot have been caused by choice. We discuss how the problem we identify applies to the basic FCP paradigm as well as to all variants that examine moderators and mediators of spreading. The results suggest a reassessment of the free-choice paradigm, and perhaps, the conclusions that have been drawn from it.
Do humans and even monkeys tend to rationalize their choices? Or have researchers for decades been rationalizing their own work because of a mathematical flaw in the experiments that led to the theory of cognitive dissonance?
- John Tierney, Monkeys, Candy and Cognitive Dissonance, NYT, Jan. 27, 2010