The Science of Personality Changes

Are you the same person you were at 16? Researchers are exploring why some people do—or don’t—evolve over a lifetime.

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Looking back on your high-school self, you’re likely to think one of two things: that your older self bears almost no resemblance to the adolescent you, or that your personality hasn’t really changed much over your lifetime. Large studies, following hundreds of people for decades, have also reached completely opposite conclusions about how personalities evolve over time, coming down on the side of either personality stability or personality change.

Where the rest of us might see empirical chaos, a growing number of personality researchers see opportunity. Rather than making sweeping statements about change and stability or dismissing conflicting studies as all somehow flawed, they are digging deeper to discover the aspects of personality that are most changeable. By identifying those traits, they can uncover why some people remain stuck in their wallflower past even as most of their peers become more extroverted, and how core personality traits can be influenced not only by unique life circumstances but also by volitional change—in other words, as the result of self-awareness and a desire to be other than how you are.

It all raises a fascinating philosophical, even existential, question: If who I am changes, is there ever truly an “I”?

It’s All Relative

“This is one of the hottest fields within personality research,” says psychology researcher Rodica Damian of the University of Houston: “What makes some people’s personality change and others stay almost the same from adolescence into old age?”

Damian led the largest study of its kind on personality change, comparing personality measurements of 1,795 people at two points in time, 50 years apart. The 2018 study used the “Big Five” personality traits—openness, conscientiousness, extroversion, agreeableness, and neuroticism—to examine how personalities changed between ages 16 and 66.

Damian’s study looked at how the whole group had changed, on average, since they were high-school students in 1960, and found that the overall score on extroversion, agreeableness, and conscientiousness rose significantly with age. Compared to their 16-year-old selves, the 66-year-olds were also, as a group, calmer and more self-confident, indicative of lower neuroticism and greater emotional stability. 

When the study looked at how people’s traits developed relative to one another, the researchers found it was more likely than not that, when compared to their peers, participants’ relative ranking on the Big Five traits (left) would stay the same between age 16 and age 66. The rising tide for those traits lifted almost all boats. 

But only “almost.”

“Although we found large overall changes, not everyone changed in the same way, which caused their relative rank on a personality measure to rise or fall,” Damian said. 

For example, 60% of people became more mature with regard to their ability to negotiate social relationships and challenges—but 40% didn’t; of those who didn’t mature, even if they initially had above-average maturity as adolescents, by the time they were seniors they were relatively immature, since the average zoomed past them. About 17% developed greater leadership personality, but most didn’t change; those 17% therefore rose relative to their peers. About half became more socially sensitive and therefore agreeable, so the ones who stayed the same were relatively less agreeable as 66-year-olds. The fact that a lot of people move up or down the rankings rather than staying at their adolescent self’s place in the pack meshes with several previous studies, which similarly found only partial “rank order stability” between childhood and early adulthood.

The amount of movement depends on the trait. People were most likely to retain their place in the pack on openness to new ideas and experiences, conscientiousness, and social sensitivity. These traits, it seems, are less subject to change. As a result, people tend to stay put, relatively speaking. But rank order on impulsiveness, emotional calm, and self-confidence is quite subject to change. That suggests significant variation in the life experiences that affect those traits (some people have them, others don’t) and in the likelihood of consciously and mindfully trying to change those aspects of their personalities (some people try, others don’t).

A World of Differences

Damian and her colleagues also looked at whether “personality profile” changed. A personality profile outlines which of the Big Five traits stand out most when others describe the individual. The study found that similarity between a person’s personality profile as a teenager and as a 66-year-old ranged wildly: from near-perfect correlation (almost no change) to a wholesale reshuffling of the relative dominance of any of the Big Five. 

“It’s quite mind-boggling that some people didn’t change at all from their younger self, whereas some people’s personality profile is completely reversed,” Damian said. 

That’s clear when scientists dig beneath averages and look at individual variations. One 2008 study that compared people at 20 and 35 found that, on average, their personality was quite stable, but individually there were huge differences: Some people’s personalities at 35 were roughly 90% identical to what they had been at 20, while others’ flipped, going from neurotic to emotionally stable, disagreeable to agreeable, closed-off to new ideas and experiences to delighting in them.

Why We Change

How do people who stay as they were differ from those who change, for better or worse? 

“Life experiences can change personality traits,” Damian said. A first romantic relationship increases extroversion and decreases neuroticism, for example. Transitioning from high school to college or work, with the greater independence that brings and the larger social world it offers, increases agreeableness, conscientiousness, and openness, and decreases neuroticism. Greater openness to new experiences brings both positive and negative life events; those, in turn, can alter other personality traits, with negative ones decreasing emotional stability (increasing neuroticism).

Greater openness to new experiences brings both positive and negative life events; those, in turn, can alter other personality traits, with negative ones decreasing emotional stability.

“The fact that we don’t all have the same experiences, and therefore change as a result, will cause some people but not others to change,” Damian said.

That’s consistent with a 2016 study of 174 people in Scotland, whose personalities were rated when they were about 14 (in 1947) and again at 77. The questionnaires—answered by the individuals and by someone who knew them well—probed self-confidence, perseverance, stability of moods, conscientiousness, originality, and desire to learn. (The Big Five didn’t exist in 1947 psychology.) There was no significant correlation between the ratings at age 14 and at 77: People rose or fell seemingly at random.

That likely reflects not only the happenstances of their lives but also their conscious choices. “Volitional change is possible,” Damian said. One can decide to be more conscientious or open to new experiences and ideas; simply exposing yourself to new experiences can make you more open to them. Similarly, forcing yourself to speak to one new person every week can increase extroversion. “Your personality influences the situations you choose,” Damian said, “but the situations you choose can influence your personality.”