Almost everyone has something they want to change about their personality. In 2014, a study that traced people’s goals for personality change found that the vast majority of its subjects wanted to be more extraverted, agreeable, emotionally stable, and open to new experiences. A whopping 97 percent said they wished they were more conscientious.

These desires appeared to be rooted in dissatisfaction. People wanted to become more extraverted if they weren’t happy with their sex lives, hobbies, or friendships. They wanted to become more conscientious if they were displeased with their finances or schoolwork. The findings reflect the social psychologist Roy Baumeister’s notion of “crystallization of discontent”: Once people begin to recognize larger patterns of shortcomings in their lives, he contends, they may reshuffle their core values and priorities to justify improving things.

Each year, Americans spend billions of dollars on self-improvement books, CDs, seminars, coaching, and stress-management programs to become better, more sociable, effective, compassionate, and charismatic versions of themselves. But beneath theories on what drives people to change, there’s a more fundamental question debated by psychologists: Can personality even be changed in the first place?

* * *

There are so many common misconceptions of what having a personality actually entails. In his controversial 1968 book, Personality and Assessment, Walter Mischel, the social psychologist best known for leading the famous Stanford marshmallow experiment, argued that any notion of consistency among personalities is largely a myth. A person’s actions in a given moment depend more on their situation, he contended, than on some enduring essence of who that person is. His research suggested a correlation about .30 (out of 1.0) between one behavior and the next.

In 1979, the psychologist Seymour Epstein conducted a series of studies in which he observed people’s behaviors on several occasions—from impulsivity to happiness, to nurturance, to problem solving. He found that Mischel was right that understanding someone’s behavior at any given moment requires accounting for the situation they’re in more than anything else. But what Mischel didn’t consider, Epstein contended, was that beyond individual moments, a person’s general character still could be gleaned from the average of their many behaviors over time. In four studies, Epstein showed that when comparing behaviors over the course of two weeks, the stability of personality shattered the .30 barrier—sometimes reaching .90.

More recent research has confirmed Epstein’s findings. The best way to think about personality traits, it seems, is as various “density distributions”: Throughout the course of the day, everyone fluctuates in their “true” selves quite a bit. Acting out of character is more the rule than the exception. Yet at the same time, it still makes sense to talk about differences in personality between people, because when whole distributions of behavior are considered, there are very consistent individual differences. For instance, almost everyone craves at least some solitude throughout the day, but some need a lot more than others.

What this new understanding of personality means is that people are only introverted, agreeable, conscientious, emotionally stable, and open to new experiences to the extent that their repeated patterns say they are. Genes certainly influence patterns of behavior (we have what Brian Little refers to as a “biogenic” nature), but there is nothing sacrosanct about being a certain way. With enough adjustments to these patterns over time, it seems that people can change who they are.

* * *

This is all good in theory, but what does it mean in practice? It’s worth noting that, even without any conscious effort, personality does appear to evolve quite a bit throughout a person’s life. Research shows that people tend to become more mature and well-adjusted as they age: The typical 65-year-old is more self-disciplined than about 85 percent of early adolescents, and more agreeable than about 75 percent of them. Social roles matter, too. As someone becomes more invested in a job, they often become more conscientious; likewise, when someone becomes more invested in a long-term relationship, they tend to become more emotionally stable and have higher self-esteem. In fact, the more the commitment is part of a person’s identity in any context, the more it appears to cause personality change.

But these aren’t the kind of changes that most people who buy self-development books are most interested in. They want to know whether they can change their personalities because they want to. Instead of changing jobs, entering a long-term relationship, or adopting a new identity, can people change their personalities intentionally?

Some studies hint at this possibility. One 2006 study found that college students who were concerned that they were becoming boring people increased their binge-drinking behavior in the hopes that they would become a more interesting person (I wouldn’t recommend this method!). Another study, from 2011, found that students strategically chose extracurricular activities that they thought would boost certain desirable characteristics, such as leadership.

More recently, Nathan Hudson and Chris Fraley, researchers at Michigan State University and University of Illinois at Urbana-Champaign, respectively, looked at a sample of undergraduates who declared their goals to change their personality across a variety of dimensions (e.g., “I want to be more talkative”) at the beginning of a 16-week semester. Then, each week, they took personality tests to measure personality growth over time.

To help certain participants with their goals, the researchers randomly assigned half of the students to engage in a “goal-setting” intervention. In this condition, the researchers reminded the students of the traits they most wanted to change and asked them to come up with specific and concrete steps (e.g., “Call Andrew and ask him to lunch on Tuesday) and to generate “if … then” implementation plans (e.g., “If I feel stressed, then I will call my mom to talk about it”). The participants were also warned that very broad goals, such as “I want to be more self-disciplined and self-controlled,” were too vague to cause any lasting change.

Over the course of the semester, the student’s goals to change their extraversion, agreeableness, and emotional stability appeared to inspire actual growth in the desired direction. For example, people who said they wanted to be emotionally stable “more than they currently are” actually increased their emotional stability each month. What’s more, people who came up with concrete plans for reaching their goals showed much greater changes in extraversion, conscientiousness, and emotional stability than those in the control group. However, the intervention did not boost growth in agreeableness beyond merely wanting to be more agreeable.

As promising as these results sound, it’s important to point out that the effects were moderate in size. The changes happened slowly over the course of the semester, and resulted in some, but not radical, change. Rather than a knock against Hudson and Fraley’s methods, this finding points toward a commonly misunderstood truth about personal growth. According to Janet Polivy and Peter Herman, at University of Toronto, many people fail in reaching their personal-development goals because they have unrealistic expectations about the speed, amount, ease, and consequences of attempts at self-change—a phenomenon they call “false hope syndrome.”

According to their theory, first, people are motivated to adopt a difficult, or even impossible, personal growth goal (e.g., “I want to be thin”). After some initial progress, they ultimately don’t reach it. But after failing, they interpret their failure in a way that makes it seem like it wasn’t inevitable; for instance, the failure was a result of just not working hard enough. So they convince themselves that with a few minor adjustments, they can still achieve success. Finally, with renewed determination, but with only minor changes to their plan or their expectations about the rate of change, they set out again, propelled by their hope for the future, only to once again be disappointed. This cycle can continue forever.

The first step to making real, lasting personality adjustments, then, it seems, is to be critical of any self-development program that touts instant, or even radical, change. Just as it takes many years to develop patterns of thoughts, feelings, and behaviors, it will take some time—perhaps many years—to alter them. But the good news is that change is possible.