Researchers have identified a key reason why people make mistakes when they try to predict what they will like. When predicting how much they will enjoy a future experience, people tend to compare it to its alternatives — that is, to the experiences they had before, might have later, or could be having in the present moment. But when people actually have the experience, they tend not to think about these alternatives and their experience is relatively unaffected by them.

In new research funded by the National Science Foundation and presented at the annual meeting of the American Association for the Advancement of Science, Daniel Gilbert, professor of psychology in the Faculty of Arts and Sciences at Harvard University, shared the findings in a presentation titled, “Why People Misimagine the Future: The Problem of Attentional Collapse.” The research was done with Carey Morewedge of Carnegie Mellon University, Karim Kassam of Harvard, Kristian Myrseth of the University of Chicago, and Timothy Wilson of the University of Virginia.

“Our predicted enjoyment is strongly influenced by the mental comparisons we make,” Gilbert says. “We expect a family reunion to be dull if we compare it with a trip to Bermuda, and delightful if we compare it with working an extra shift. But these comparisons end up having relatively little influence on our actual experience of the family reunion because the acts of greeting relatives and grilling hamburgers demand our attention, leaving us little time to think about all the other things we might have done instead.”

Gilbert presents the results of four experiments, all involving predicted versus actual enjoyment of a very simple experience — eating potato chips. In three of the experiments, participants predicted how much they would like eating potato chips before, after, or instead of eating a much better food (chocolate) or a much worse food (sardines). They then ate the chips and reported how much they liked them. The results showed that the chocolate and the sardines had a large impact on participants’ predictions, but no impact whatsoever on their actual experiences. The participants who compared the chips with sardines overestimated how much they’d enjoy eating the chips, and those who compared them with chocolate underestimated how much they’d enjoy eating the chips.

Why does this happen? “Experience typically demands our attention,” says Gilbert, “leaving us little time to think about the alternatives to it.”

To demonstrate this, participants in a fourth experiment were asked to eat the potato chips to the beat of a metronome. Those who ate the chips at a normal pace made the same mistake as did participants in the previous experiments; those who ate the chips at an unusually slow pace did not. That is, participants who ate slowly actually did enjoy the chips more when the alternative was sardines than when the alternative was chocolate — just as they had predicted.

Gilbert argues that slowing down the experience of eating gave participants the opportunity to think about the chocolates and sardines.

“A very slow family reunion may well be worse if the alternative was Bermuda than if the alternative was working an extra shift,” says Gilbert. “When experiences don’t demand our attention, our minds are free to wander to all the other things we might have been doing instead. If those things are better, we feel worse, and if they are worse, we feel better.”

Gilbert and his colleagues theorize that one of the key reasons people mispredict their enjoyment of future events is that they mistakenly think they will be making comparisons when the event actually happens.

“We think we will be thinking about the roads not taken,” says Gilbert, “but the fact is that whatever road we choose in life requires that we navigate it, and doing so limits our ability to compare that road to its alternatives. Life’s untaken roads come to mind much less often than we expect them to.”

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