Choice Blindness – What are we forgetting?

Photographer: Mark Hanlon

MIT is currently in its Independent Activities Period (IAP). Each January students take a break from regular class work and experience a variety of mini courses ranging from weighty subjects like “Energy Storage Solutions” to just for fun topics like “Build Your Own Electric Guitar.” IAP is a great way to brush up on skills or try something completely new. Fortunately for me the non-credit courses are open to alumni so I’ve spent my week immersed in “Statistics and Visualization for Data Analysis and Inference” (very useful but not much fun) and “Philosophy of Cognitive Science – Choose your own adventure!” (esoteric but mind-bendingly interesting).

Yesterday in the cognitive philosophy course we covered research by Petter Johansson and his colleagues from Lund University. In a 2005 Science paper entitled “Failure to Detect Mismatches between Intention and Outcome in a Simple Decision Task,” the authors present a series of experiments which lead to a construct Johansson calls Choice Blindness. As stated in the paper’s introduction:

“A fundamental assumption of theories of decision-making is that we detect mismatches between intention and outcome, adjust our behavior in the face of error, and adapt to changing circumstances. Is this always the case? We investigated the relation between intention, choice, and introspection. Participants made choices between presented face pairs on the basis of attractiveness, while we covertly manipulated the relationship between choice and outcome that they experienced. Participants failed to notice conspicuous mismatches between their intended choice and the outcome they were presented with, while nevertheless offering introspectively derived reasons for why they chose the way they did. We call this effect choice blindness.”

It is worth taking a more detailed look at the experiment to grasp the full magnitude of this surprising result. Subjects (male and female) were presented with pictures of two different female faces at a time on two separate cards. They were then were asked to point to the picture they found the most attractive. In the manipulation condition, the experimenter performed a slight of hand card trick and presented back to the subject the card they did not pick and asked them to justify their choice. In most cases these subjects proceeded to justify why they choose this other woman as if it was the card they had intended to choose all along, completely unaware of the fact that they DID NOT choose this picture. Amazing!

Why does this happen? The authors suggest that subjects fail in introspection. Johansson believes that, at the time of outcome, subjects no longer have access to their original intentions. A “fundamental assumption of theories of decision making [that] intentions and outcomes form a tight loop” is somehow broken.

There may be another, somewhat complementary, explanation in “motivated forgetting.” Motivated forgetting suggests that given a strong motive and suitable vehicle for belief, people are capable of forgetting information that does not suit their motive and falsely remembering alternative “facts” that do. Note that motivated forgetting involves the subject authentically forgetting the true facts and not just conveniently pretending to forget them for a social/external benefit. In the case of the card experiment, subject desire for consistency may be a strong enough motive to cause subjects to forget their original intent and remember it as it’s opposite.If motivated forgetting is playing a role one might predict that subjects faced with a different motive would not exhibit choice blindness. The following experimental idea could use some work but what if subjects were evaluating and choosing between two race horses before a race at the betting window. The experimenter would then place a bet on the behalf of a subject based on the subject’s choice. In the manipulation case experimenters would ask for a bet, making sure the subject overheard them, to be placed the opposite horse to the one the subject chose. If motivated forgetting is playing a role, I would predict that when the false choice horse won subjects would not remember that this horse was not their original choice and be able to explain the reasons they “chose” this false horse much like in the Johansson experiment. An important difference would arise when the false choice horse lost and the true choice horse won. In this case subjects may remember having actually chosen the winning horse as their motive is now different. This second result would not be predicted with choice blindness.

Breadcrumbs of Self-Deception

Can there be a benefit to forgetting and, if so, do people have a mechanism that enables them to forget? It is a bit counterintuitive to think that we might benefit from forgetting but with a little effort it is not difficult to think of things we might prefer not to remember. Perhaps we would rather forget some particularly embarrassing moments from high school, the time of an appointment we did not really wish to keep, or even the displeasure of watching the new Indiana Jones movie. Might there also be possible benefits from forgetting the true justification for making a decision?

As discussed previously, research by Christopher Hsee describes how people incorporate unjustifiable information into their decision-making. The vast majority of people do not want to see themselves as making unethical decisions. As such, Hsee’s hypothesis is that people will only incorporate unjustifiable information when the decision-weighting of the justifiable information is vague and elastic. Unjustifiable information is thus incorporated indirectly and subconsciously through readjusting the weighting of the justifiable information. People thereby make unjustified decisions yet preserve their self image as ethical and just.

As an example of the phenomenon, one of Hsee’s studies uses a scenario involving a condo appraiser who, for different subject groups, is motivated either to deflate or inflate the valuation of a property. Their motivation derives from an unjustifiable conflict of interest where the condo seller/buyer is actually the fiancée of the appraiser. Hsee shows that appraisers only inflate/deflate values when there is substantial elastic wiggle room in how the appraiser evaluates the justifiable attributes of the apartment like age of the appliances, carpeting, etc. and that they do not make biased assessments when the attribute weightings are not subjective.

Hsee’s experimental results and those of others seem to strongly support this theory and it is very likely correct. However, let’s consider an alternative explanation centered on motivated forgetting. First, grant the assumption that people do not want to consider themselves as unjust. Next, assume decision subjects are at least conscious of the temptation to incorporate unjustifiable information. I believe Hsee would agree with this awareness. However, motivated forgetting goes further to suggest that at the time of the decision subjects are consciously aware of their incorporation of unjustified information. These subjects are conscious of their transgression yet are careful to lay out a logical story of how the same conclusion could be reached using only justifiable information. The story may partially be constructed to explain the decision to others but the story serves a larger purpose for the decision maker himself. After the story is created the subject very promptly and conveniently forgets the true basis of their decision. Then, if necessary at some future point, they can follow the story like “breadcrumbs of self-deception” to retain their world view as a just individual. Like Hsee, the motivated forgetting approach assumes subjects will only incorporate unjustifiable information when a decision biased by motive can be justified based on a manipulation of the justifiable information. This is because without sufficient nuggets of justifiable information to weave a breadcrumb story around, the motivated forgetting mechanism would not function. Subjects know when they would not be able to fool themselves.

As a theory, motivated forgetting seems to add little value here as it predicts the same outcomes as Hsee’s elasticity hypothesis. Also, in practice it would be extremely difficult to verifiably demonstrate that motivating forgetting is occurring. Perhaps someone brighter than me will have an idea for a good experiment.