How much will your personality, values and preferences change over the next decade? Probably more than you think, at least according to a recent paper, “The End of History Illusion“1 by a team of psychologists at Harvard and the University of Virginia.
In a number of separate experiments, the authors asked a total of over 19,000 people between 18 and 68 to measure their current personality, values and preferences2. Half of them were also asked to complete the assessment as they believed they would have done ten years earlier, while the other half were asked to predict what they would say in ten years’ time.
Next the authors looked at the data on how people believed they had changed in the past decade (past change data) and the data on how people believed they would change in the next decade (future change data). They compared the future change data of 18 year olds in the study with the past change data of 28 year olds, the future change data of 19 year olds with the past change data of 29 year olds, and so on.
If people were accurate in their predictions of how much they will change, you would expect the data sets to match. In fact, the experiments consistently showed that people underestimated how much they would change.3
The results show that people change throughout their lives (although the rate of change slows as people get older), a result consistent with other studies.
More interestingly, while the participants in the study were able to recognise that they have changed in the past, people of all ages seem to believe that that process of change has come to an end for them. As the paper’s authors say:
[They] seem to believe that the pace of personal change has slowed to a crawl and that they have recently become the people they will remain.
Quoidbach, J., Gilbert, D. T., & Wilson, T. D. (2013). The End of History Illusion. Science, 339(6115), 96-98. Archived by Archive.org.↩
Personality was assessed using the Ten Item Personality Inventory to measure the big five personality traits. For values, participants were asked to state the importance to them of ten basic values such as hedonism, success and security. For preferences, they were asked to name their favorite type of music, favorite type of vacation, favorite type of food, favorite hobby and best friend.↩
Additional tests were performed to rule out alternative possible reasons for the discrepancy: overestimation of the level of past change, different ways of interpreting terms with regards to past and future estimates, and underestimation of future change due of uncertainty over what the change would look like.↩
This is just one study in psychology, so we shouldn’t put too much weight on the findings. Nevertheless, the sample size was reasonably large, we’re not aware of any conflicting papers, and the result is intuitive. With this in mind, we think it more likely than not that the paper’s conclusions are accurate.↩