Imagine yourself a decade from now; you're likely to picture someone pretty much like yourself - with maybe a little less hair and a few more wrinkles.
But if you think back to how you were a decade ago, you're likely to see a substantial difference. The younger you probably had different values, different interests, different ambitions.
People tend to see the future as much more like today, discounting how much they've changed over time, according to a new study from Harvard and University of Virginia, entitled "The end of history illusion."
The view that all our changes are in the past leads to mistakes of prediction, such as when a 20-year-old gets a tattoo - unable to believe that its appeal will wear off some day, according to study author and Harvard psychology professor Daniel Gilbert.
These judgment errors also have financial consequences, he says, leading us to overestimate how much something will be worth to us in the future.
In one part of the study, published Thursday in the journal Science, researchers asked participants how much they would pay for tickets to see their favorite band in concert in 10 years. They said $130. Other participants, asked how much they'd pay to see the band that was their best-loved a decade ago, said they would pay only $80.
"We would be very well served to make decisions with the understanding that who we are now is just a point on a changing line," he says.
The study, based on a series of surveys, included a total of 19,000 participants, ages 18-68, most solicited from the website of a French television program.
Mike Ross, professor emeritus of psychology at the University of Waterloo, in Ontario, says he found the study quite provocative. "It probably leads to more questions than answers, but the questions it leads to I think are very interesting."
He says the study made him wonder whether people who are dissatisfied with their lives make the same errors of prediction. Perhaps they are more likely to expect changes in the future because they want that change to happen.
He also questioned whether the illusion that all of our changes are in the past is a problem. "I'm not sure that it is."
Even though the survey participants expected life to stay the same, they were obviously open to change because they reported having changed, Ross says.
Shane Frederick, an associate professor of marketing at Yale University, says he also found the topic interesting; he notes its similarity to research he published in 2003.
Frederick says the study's central claim, that people change more than they expect they will, is "plausible, but difficult to demonstrate and certainly not convincingly demonstrated here."
People may be less precise in their predictions of the future than their memories of the past, Frederick says, simply because it's silly to be precise about something you can't know. "This gap is compatible with full rationality, and is not necessarily evidence of any sort of 'illusion.' "
Gilbert acknowledges that he is just speculating about why people underestimate how much they're going to change in the future. But that doesn't contradict the fact that they will.
"When people look back on a particular decade, do they remember more change than they predict (for the next decade)? The answer is yes," Gilbert says.