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Dissonance on cognitive dissonance

Chris Wiggins points me to this column by John Tierney reporting research by Keith Chen on cognitive dissonance–that well-known phenomenon whereby we change our preferences to match our pre-existing decisions (for example, not wanting to hear bad news about one’s preferred presidential candidate). Chen wrote a paper claiming that cognitive dissonance is not nearly as important as everyone thought it was. For Tierney’s column, Chen writes,

All of the studies I [Chen] talk about take as their basic model a famous and incredibly influential experiment by Jack Brehm in 1956; the first study, in fact, which psychologists took to demonstrate cognitive dissonance. In Brehm’s study and its modern variants, subjects are first asked to rate or rank a bunch of goods based on how much they like them. Then, subjects are offered a choice between two of the goods they just rated, and are told they can take the good they choose home with them as payment for the study. They are then asked to re-rate all of the original goods; cognitive dissonance theory suggests that people would have a better opinion of the good they choose after choosing it than before.

So, for example, subjects may first be asked to rank 15 goods from 1 to 15, with 1 being the best and 15 being the worst. Then, a subject would be asked to choose between two goods they initially ranked similarly, say the goods they ranked 7 and 9. After making this choice, psychologists have looked at whether, if asked to rank these goods again, the chosen good rises in rank, and if the rejected good falls. This seems like a perfectly reasonable thing to look at; but there’s a big problem in how this has been done.

The problem is, when you ask subjects to choose between goods they ranked 7 and 9 (call these goods A and B), many subjects choose good B, (the good they initially ranked lower). Typically about one-quarter to one-third of subjects do this. Now, why people do this isn’t entirely clear, but one thought is that it indicates that asking subjects to rank goods from best to worst isn’t a perfect measure of how they feel. Some of them might not take the task that seriously; some might get confused by all the choices. So while they’ll initially rank B below A in the list of items, when they actually focus just on those two items they realize they actually prefer B to A.

The real problem, though, is what psychology studies did with subjects who “switched” — that is, those who chose the good they initially said they liked less. What many studies did (following the original Brehm study) is to exclude from the study those subjects who choose good B. Is this a problem that can bias their findings? Yes, if we think that the subjects being excluded from study are systematically different from those who aren’t. Specifically, when we drop subjects who choose good B over good A, we may be systematically dropping subjects who like good B (more than good A). Ignoring this possibility is like ignoring Monty’s choice and what it tells us about where the car is likely to be. By throwing out subjects, a study “stacks the deck” of remaining subjects with people who like good A more than they like good B. In fact, all remaining subjects have signaled they feel that way, twice. Maybe it shouldn’t be a surprise then, when asked to re-rank these items, the rank of good A rises; it originally ranked 7 from a larger group, then those who on second thought didn’t like it so much, were dropped.

Many studies that examine “spreading” look at how much A goes up and B goes down only for those people who chose A (as just described). Others look at whether the chosen good (A if you choose A and B if you choose B) went up and the non-chosen went down for everyone. This is also problematic for exactly the same reason; we shouldn’t be surprised that people like the things they choose, and the experiment needs to take that into account before it can correctly claim that dissonance is occurring.

This is interesting. I’m certainly sympathetic to the argument that preferences don’t exist, independently of the settings in which they are chosen. (See here and here.) On the other hand, the desire to avoid cognitive dissonance seems real to me. I’d like to see how this work fits into the general literature on the topic. (Also, I’m not quite sure why Tierney calls this “social psychology.” Isn’t it “cognitive psychology”? I’m sure there’s something I’m missing here.


  1. wolf says:

    I am certainly not an expert, but I think one problem of Chen's argument is that cognitive dissonance is not only about choosing goods — it is much more generally about how people cope with "dissonant" affects, behaviors, and cognitions. And from what I remember (it's been six years since I had my exam in social psychology), the cognitive dissonance effect is going to happen only if people need to explain their behavior to someone else and if they are not going to find a sufficient explanation. So cognitive dissonance might just not apply to rather artificial choice experiments. Above that, Chen's example of ranking isn't really good from an experimental design point of view. Ranking 15 goods is a rather tedious and excruciatingly boring task: people aren't really going to put that much effort in getting the ranking right, especially not in the middle of the rank order. You will only get a fair amount of consistency for the objects at the extremes. The reason might just be that people do not care enough to stay consistent with their first attempt to rank the objects in the middle.

    That means I agree with you that preferences are often only conditional on the settings. Norbert Schwarz for example has done research on how people make up attitudes about something they are asked "on the spot".

    Now for the "cognitive" vs. "social" psychology question. Even if it is named "cognitive dissonance", the theory would be counted as social psychology, or at least social cognition. A lot of what social psychologists do is actually not about individuals interacting, but about individual behavior on an let's say everyday scale, whereas cognitive psychologists usually analyze processes on a smaller scale, working on attentional processes, basic processes of memory, perception, and thinking, but not so much using everyday tasks, and instead using reaction time experiments and the like.

  2. jfalk says:

    The real cognitive dissonance in this article is far more interesting, or at least it should be to a Bayesian. The result on context-dependent preferences is now rejected in the first seminal article in which it appears, ie no one seems to dispute that the two-thirds preference for the unrejected good is in fact exactly what we'd expect if there were no context dependence at all. Thus, everyone Bayesian posteriors need to be recalculated since the original experiment is now disconfirming, not confirming. Instead, of course, you get generalities about how not every replication used this faulty design, ie, let's find a way to throw out the data but keep the posterior result. Cognitive dissonance indeed!

  3. Andrew Pratley says:

    I'd agree with wolf regarding the study to be under the 'branch' of social psychology. From my degree, social psychology covered the areas of research regarding how people interpret and interact with the world. Much of this can be considered 'sub conscious', that is there no explicit rational and reasoning. As a result much of social psychological research is our collective best estimate, as opposed to many other areas of research where there is less doubt about the validity. Examples of research in social psychology include learned helplessness study and the shock experiments by Stanley Milgram. In both cases we can "see" the actions/decisions made by people, however the current theories may not explain the underlying 'sub conscious process'. The current theories represent the best estimate that have not proven to be false (that's a key criteria).

    When psychologists use the phrase 'cognitive' in titles it seems to refer to actual brain processes. At my university the course cognitive science (in the School of Psychology) covered the topic of how we actually see. I.e. how light enters the retina, what part of the brain processes this, occlusion, depth perception etc. I have noticed this usage of terminology in other areas.

    Given that the field of psychology is to understand human behaviour, theoretically all studies in someway relate back to the human brain. Therefore the entire field is 'cognitive psychology' if you take the literal definition of cognitive meaning 'brain'.

  4. Greg says:

    I think the real issue with cognitive dissonance theory is that it is not necessary to explain any of the results it purports to explain and it doesn't make any risky predictions that turn out to be true.

    For example, the simplest explanation of the choice experiment is that you've already inhibited your response to the one you didn't choose. When presented with a new choice, you have a choice between an inhibited and uninhibited option. There doesn't need to be any talk of "rationilizing" or justifying your choices to yourself.

    As for why it's social psychology, I think that's just a historical accident. Several cognitive psychologists study "high level cognition" that don't map onto explicit brain processes.

  5. John says:

    Am I correct that Chen is saying that by dropping 1/4 to 1/3 of the experiment subjects, the researchers are biasing the results; and if the subjects aren't dropped, the experiments no longer show signs of cognitive dissonance?

    That question aside, I cannot fathom how the experiments are supposed to show cognitive dissonance in the first place. I don't see anything dissonant in choosing the item one has ranked as preferred.

    I also don't see how choosing inconsistent with stated preferences necessarily eliminates cognitive dissonance. It seems that people could have a sort of buyer's regret, where on second thought they decide they mis-ranked them initially. Or, similar to Andrew's remark, they may rank all the goods with a mind frame that's trying to imagine what they generally prefer, rather than what they would take right now. (I would ranks steaks over grilled-cheese sandwiches, but when given the actual choice, I might just be in the mood for a grilled cheese.)

    The type of experiments on cognitive dissonance that I learned in school are wholly different; e.g., subjects perform a task and are randomly paid for doing it or not paid for doing it. The subjects paid for the service report they did not enjoy doing it; those not paid report that they did enjoy it. Cognitive dissonance explains this in that those not paid have to come up with a reason for doing the task, so they unconsciously decide that they enjoyed doing it.

    Here's a neat version of the Monty Hall problem that shows the power of unstated assumptions. When you choose that the host "knows" he's giving information; "Doesn't know" means he's choosing randomly.

  6. Louisa Egan says:


    I'm the lead author of the monkey cognitive dissonance study that Keith critiqued. We have a new paper just out in the Journal of Experimental Social Psychology that gets around Keith's critique–even with preference-blind choices, we see that monkeys and kids still devalue that which they reject. By Keith's logic, we should not obtain this effect.

    You can check out the new paper on my website:

    Or you can access it through the Journal of Experimental Social Psychology.