Another possibility is that people "might well anticipate substantial change, yet not know how they would change, and thus, just predict the status quo"
To give a specific example: If personality can be modeled over time as a martingale)—meaning that the expected future personality is always equal to the current personality—then it is quite appropriate for participants to provide their current personality as a prediction of their future personality, even if they think that the standard deviation of the martingale is large.
More generally, given the current personality and random variable
following the distribution of predicted future personality, the predicted change in personality can be characterized by the expected absolute deviation
) or the expected squared deviation
%5E2)). However, study 1 in the paper measured the absolute expected deviation
%7C) instead, which is a poor measure. (This limitation of the study is understandable because collecting data on
and
) is relatively easy.)
The authors tried to circumvent this limitation in a replication of study 1 by asking each participant to directly predict change rather than inferring predicted change from and
). P. 97 column 2:
Instead of being asked to report or predict their specific personality traits, these participants were simply asked to report how much they felt they had “changed as a person over the last 10 years” and how much they thought they would “change as a person over the next 10 years.”
I think there is an interpretational issue here—we cannot be sure if the participants actually estimated something similar to the expected absolute deviation ). If the participants relied on imagining a future self, then this will again give the absolute expected deviation
%7C).
I'm surprised that the authors did not report whether any of the Big Five personality domains mediated this "end of history illusion". That seems like an obvious thing to check. Maybe they're saving that for a later paper.
"The single best way to make predictions about what you're going to want in the future isn't to imagine yourself in the future, … it's to look at other people who are in the very future you're imagining," [Gilbert] says.
In other words, take the outside view.
The distinction you highlight between the expected absolute deviation and the absolute expected deviation seems extremely important; Jordan Ellenberg says that the study is measuring one and calling it the other, and goes on to say (emphasis added)
...Let me be clear: I don’t think the authors are trying to put one over. This is a mistake — a somewhat subtle mistake, but a bad mistake, and one which kills a big chunk of the paper. Science should not have accepted the article in its current form, and the authors should withdraw it, revise it, and resubmit i
A current article in Science reports on this study about how good people are at predicting what their future selves will be like. Not very good, apparently. Daniel Gilbert, a psychologist at Harvard, with other colleagues conducted several experiments online, in which 19,000 people were asked about such things as personality traits, preferences in music, etc., answering about the present, about themselves 10 years earlier, and about what they expected 10 years hence. More precisely, this not being a longitudinal study, people of any age X predicted less difference with their X+10 selves than people of age X+10 recollected of themselves at age X. The effect did not go away with increasing age: 58-year-olds still expected less change in the next 10 years than 68-year-olds reported in the last ten.
Gilbert and colleagues call this effect "the end of history illusion," because it suggests that people believe, consciously or not, that the present marks the point at which they've finally stopped changing.
"What these data suggest, and what scads of other data from our lab and others suggest, is that people really aren't very good at knowing who they're going to be and hence what they're going to want a decade from now," Gilbert says.
Someone suggests an alternative explanation:
Another possibility is that people "might well anticipate substantial change, yet not know how they would change, and thus, just predict the status quo"
An actionable moral:
"The single best way to make predictions about what you're going to want in the future isn't to imagine yourself in the future, … it's to look at other people who are in the very future you're imagining," [Gilbert] says.