Jordi Quoidbach, Dan Gilbert and Timothy Wilson claimed to have shown that people of all ages underestimate how much their personalities, preferences and values will change in the future. Ideally the psychologists would have asked people to predict the amount they'd change, and then followed them up later to compare the actual change with the prediction. They didn't do that.
Instead, their favoured approach was to survey over 7,000 people aged 18 to 68 and to ask some of them - "the reporters" - to recall their personality ten years ago, using a personality questionnaire, and to ask others - "the predictors" to estimate their expected personality ten years hence. All participants also answered questions about their current personality. The key contrast was the amount of difference between recalled vs. current personality (documented by reporters) and the amount of difference between predicted and current personality (documented by the predictors). Across every decade of life, the former was much larger. People thought their personality had changed more than they thought it would change.
But there are some serious problems here. First off, there's no actual data on real change. How do we know this is a delusion of prediction? Perhaps the reporters are wrong about how much they've changed. Quoidbach's team realised this so they looked at data from a separate longitudinal study that really had followed people over time (once in 95-96 and again in 04-06), allowing examination of actual personality change.
Unfortunately, this MacArthur Foundation Survey of MidLife Development in the United States (MIDUS) used a completely different measure of personality. "Direct comparison of the data was not possible," Quoidbach et al confessed. Nonetheless, after comparing the amount of personality change in the MIDUS survey with amount of change estimated by reporters in their own study, the researchers said the change was "almost identical", and "substantially larger" than the change predicted by the predictors in their study.
But there's another serious issue with the new research, which was highlighted in a recent blog post: that is, the predictors might well have believed that their personality will change, but they didn't know which direction it will change in. Take extraversion. Perhaps they will become more shy, perhaps more gregarious? Without knowing the direction of change, the most accurate prediction is to report no change in extraversion from their current score.
Quoidbach's group hinted at this problem by acknowledging that participants may not "feel confident predicting specific changes". To overcome this, they asked over a thousand people to answer a non-specific question, estimating how much they felt they'd changed as a person, or how much they would change. It doesn't entirely deal with the direction of change issue, but again, "reporters" estimated more change than "predictors" predicted.
Yet another survey with thousands more participants asked them to recall or predict changes in their values over ten years - things like hedonism and security. Again, people reported more change in their values than they predicted. Recalled change was more modest in older participants, but again the difference in recall and prediction occurred at every decade. However, this survey has the same problems as before - the issues of memory distortion and predicting bi-directional change - and in this case they went unaddressed.
Gathering yet more data, the researchers surveyed thousands of people about their preferences in the past compared with now, and asked others about their likely preferences in the future, compared with now - things like favoured holidays, taste in music and food. The idea of this study was to eliminate memory bias. Quoidbach et al reasoned that people have an accurate sense of their past preferences, although they didn't reference any data to support this claim. People recalling the past again appeared to have changed more than was anticipated by those looking ahead.
A final, far smaller study attempted to address the practical implications of our failure to anticipate how much we will change in the future. One hundred and seventy adults were split in two groups. One stated their current favourite band and said how much they'd pay to see them in ten years. The other group reported their favourite band ten years ago and said how much they'd pay to see them today. There was a big difference - those looking ahead said they'd pay 61 per cent more to see their current favourite band, as compared with the price the retrospective group said they'd pay to see their former favourite band today. "Participants substantially overpaid for a further opportunity to indulge a current preference," the researchers said.
But was this a fair comparison? The retrospective group know things about their former favourite band that the future group couldn't possibly know about their current favourite band. For example, perhaps members of the retrospective group didn't like their chosen band's follow-up albums, perhaps they already saw them in concert many times over the last ten years. Maybe the future group were optimistic about the future creative output of their current favourite band. In short, there are so many other factors at play here, besides participants' beliefs about the stability of their own preferences.
Convinced by their own demonstrations of the End of History Illusion, Quoidbach et al speculated about the possible causes. One explanation, they suggested, is that the effect is a manifestation of our gilded view of ourselves: "most people believe that their personalities are attractive ....," the researchers wrote, "having reached that exalted state, they may be reluctant to entertain the possibility of change." But this explanation seems to ignore the self-doubt and pessimism that blights many people's lives. Quoidbach's other proposal is that the End of History Illusion is a manifestation of the fluency heuristic - because it's tricky to imagine change in the future, we infer that change is unlikely.
These speculations are premature. It would be easier to believe in the End of History of Illusion if there was data on actual change, rather than a reliance on participants' memories of themselves in the past. Even if the effect is real, it's also not clear if this is a general bias about the future that extends beyond our beliefs about ourselves. What predictions would we make about the future change of other people? Or about human culture in general? Here's one thing that surely won't change - slick psychology papers with eye-catching titles getting lots of attention.
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Quoidbach J, Gilbert DT, and Wilson TD (2013). The end of history illusion. Science (New York, N.Y.), 339 (6115), 96-8 PMID: 23288539
[thanks Thom Baguley for help with understanding some of the methodological issues]
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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