In Thinking, Fast & Slow, Nobel winner Daniel Kahneman (click here previous post about Thinking, Fast & Slow) talks about the two selves people have: the experiencing self and the remembering self. The terms are self-explanatory and vacations are a good way to think about them. The part of us that is enjoying the vacation is the experiencing self, while the part that is reliving it later (sometimes years later) is the remembering self. Neither one may be more important, but the emphasis we place on one or the other could determine our behavior. So, for example, you can enjoy the vacation or take plenty of pictures to relive it later, depending on the self that is more important. A way of finding out which self is more important is to ask ourselves whether we would go on a certain vacation if we could only enjoy it, but not take any pictures (or video, etc).
Now the issue with the two selves is that the remembering self is the one keeping score and it is prone to biases. Through a variety of experiments Kahneman and his colleagues have found that for the remembering self peaks and ends matter while duration does not. Let’s look at a study among patients undergoing a colonoscopy, where data were collected to indicate the pain that they felt at specified intervals as they were undergoing the procedure (before anesthetics came into wide use). There are two patients A and B whose procedure lasted respectively 8 minutes and 24 minutes. For patient A the procedure was essentially a short intense burst ending with pain, while for patient B it was a longer burst with ups and downs and ending with pain slowly dwindling. When asked afterwards about pain during the procedure how would we expect them to answer?
Patient B experienced pain for three times as long as Patient A and spent at least as much at any level of pain as patient A (as given by their ratings). But in the later evaluation they (or specifically their remembering self) gave scores that showed that patient A had a much worse experience than patient B. Why? Even though patient A objectively experienced less pain, it was his “bad luck” that it ended at a bad moment (of high pain) leaving an unpleasant memory. Since the remembering self gives more prominence to peak experiences and less to duration, objectively worse experiences are misremembered as being better.
It’s not hard to see where I’m going with this. One could argue that much of the survey research industry is at the mercy of the remembering self. Especially so are the ones where people are asked to remember specific experiences. How might satisfaction scores, for example, be affected by the filter of the remembering self? Several periods of good levels of satisfaction may not be able to compensate for a sudden drop due to one bad episode. Conversely when people say they are dissatisfied it may not be because the company did something very different, compared to what it did with a more satisfied customer. The measurement could just have been ill-timed, or there could have been a particularly bad episode which just could not be wiped out by a string of good (but not great) episodes. Ad evaluation may be affected by specific high or low points in the ad, rather than the overall evaluation. You could probably come up with even more examples. Of course, one can certainly hope that large sample sizes will help in canceling at least some of these biases. But given the inherent problems it would seem that we should try to avoid taxing the remembering self whenever possible.