Field of Science

Sorry, New York Times, cognitive dissonance still exists

Earlier this week, New York Times columnist John Tierney reported a potential flaw in a classic psychology experiment. It turns out that the experimental finding -- cognitive dissonance -- is safe and sound (see below). But first, here are the basic claims:

Cognitive dissonance generally refers to changing your beliefs and desires to match what you do. That is, rather than working hard for something you like, you may believe you like something because you worked so hard for it. 

Laboratory experiments (of which there have been hundreds if not thousands) tend to be of the following flavor (quoted from the Tierney blog post). Have someone rate several different objects (such as different colored M&Ms) in terms of how much they like them. From that set of objects, choose three (say, red, blue and green) that the person likes equally well. Then let the person choose between two of them (the red and blue M&M). 

Presumably (and this will be the catch) the person chooses randomly, since she likes both equally. Say she chooses the red M&M. Then let her choose between red and green. You would predict that she would choose randomly, since she likes the two colors equally, but she nearly invariably will be the red M&M. This is taken as evidence that her originally random choice of the red M&M actually changed her preferences to where she now likes red better than either blue or green.

The basic problem with this experiment, according to M. Keith Chen of Yale and as reported by Tierney, is that we don't really know that the person didn't originally prefer red. She may have rated them similarly, but she chose red over blue. The math works out such that if she in fact already preferred red over blue, she probably also actually preferred red over green.

Tierney calls this a "fatal flaw" in cognitive dissonance research, and asks "choice rationalization has been considered one of the most well-established theories in social psychology. Does it need to be reconsidered?"

Short answer: No.

First, it is important to point out that Chen has shown that if the original preferences were measured incorrectly, then this type of experiment might suggest cognitive dissonance even where there is none. He does not show that the original measurements were in error. 

However, even if that were true, that would not mean that cognitive dissonance does not exist. This is a classic problem in logic. Chen's argument is of the following form: If Socrates is a woman, then he is mortal. Socrates is not a woman. Therefore, he is not mortal.

In any case, cognitive dissonance has been shown in studies that do not fall under Chen's criticisms. Louisa Egan and collaborators solved this problem by having their subjects choose between items they couldn't see. Since the subjects knew nothing about the items, they couldn't possibly have a pre-existing preference. Even so, they showed the classic pattern of results.

By all appearances in the Tierney article, Chen is unaware of this study (which, to be fair, has not yet been published). "I wouldn't be completely surprised if [cognitive dissonance] exists, but I've never seen in measured correctly." This is hard to believe, since Chen not only works in the same university as Egan, he is a close collaborator of Laurie Santos (Egan's graduate advisor). It's not clear why he would neglect to mention this study, particularly since this blanket critique of cognitive dissonance research in the New York Times is embarrassing to Egan and Santos at a time when Egan is on the job market (and it appears to have a lot of people upset). 

Thus, it's puzzling that Chen claims that no existing study unambiguously shows cognitive dissonance. He might, however, be able to make the weaker claim that it is possible that some studies that have been claimed to show cognitive dissonance in fact to not. That is a reasonable claim and worth testing. In fact, Chen reports that he is testing it now. It is worth keeping in mind that for the time being, Chen has only an untested hypothesis. It's an intriguing and potentially valuable hypothesis, but there isn't any evidence yet that it is correct.

See the original article here.


Unknown said...

Even more confusing is that the original and most famous cognitive dissonance study doesn't use a paradigm even remotely like this one, and is completely immune from this problem. So how could Chen possibly believe this result would overturn all of cog. diss. research?

Fab said...

Chen might have been aware of Egan's study as he cited Egan, Santos and Bloom (2007, Psych. Science) showing DC among capuchin monkeys.