Most people think of personality traits as set in stone. We consider them to be as fixed as our eye color. For example, you might tell yourself, “I’m just a perfectionist,” or “I’m the type of person who can’t get organized unless it’s the last minute,” or even “I’m too emotional.”

Most of the common personality tests you’ve probably taken online or in your HR office reinforce the idea that you have a set “type” and that, if you build your life around it, things will go smoother. For instance, your test results may say that if you’re naturally sensitive, you should avoid high-stress jobs. Or, if you’re on the introverted side, you might not be suited to leadership roles.

If I had taken a personality test when I was 18, the results would have reflected my tendency to be irresponsible (like skipping math class so much I had to repeat it the following year). They also would have reminded me that I was painfully self-conscious in social situations.

Now, when I tell people that I used to be lazy and shy, they don’t believe me. They can’t square the person I am now, a successful academic who routinely speaks in front of large audiences, with the kid who “cleaned” by stuffing things under the bed.

What if I had let a personality test limit who I could become? Would I have told myself that I wasn’t cut out for getting a PhD, writing books (and meeting deadlines!), or getting out in front of people to share the findings from research?

Fortunately, I didn’t know I was “supposed” to choose my goals according to my type. I found something I was interested in (psychology) and then gradually shaped the traits I needed to be successful on this path.

And this isn’t just my experience. Longitudinal studies that follow people for decades show that personality continues to evolve across the lifespan. Even more exciting, we are in the driver’s seat when it comes to the direction of that change.

In fact, my research, as a clinical psychologist with a specialization in personality change, shows that we can see 20 years’ worth of natural personality change in 20 weeks when we take specific actions.

Personality change is not to become someone else entirely, but to become more of who you need to be to create the life you want.

The basics of personality change

Personality is your characteristic way of thinking and behaving. And while it might sound impossible to change personality, people change how they think and behave all the time. If you start to think “being on time shows others that I respect them,” feel pride when you arrive at brunch before your friends, and engage in new behaviors that increase your timeliness (e.g., getting up with an alarm, setting appointment reminders), you are embodying the characteristics of a reliable person. If you maintain these changes to your thinking, emotions, and behaviors over time—voilà!—you are reliable.

Practices drawn from cognitive-behavioral therapy (CBT) are really useful for shifting traits. CBT techniques are relatively simple, and you don’t need to visit a therapist if that’s not something you’re into.

The first component involves changing your thinking patterns (this is the “cognitive” piece). You have to become aware of your thoughts to determine whether they’re keeping you stuck acting in line with a particular trait. For example, if you find yourself thinking “people are only looking out for themselves,” you are likely to behave defensively around others.

The behavioral component involves becoming aware of your current action tendencies and testing out new responses. If you are defensive around other people, they will probably respond negatively to you (e.g., withdrawing, snapping at you), confirming your belief that you can’t trust others. By contrast, if you try behaving more openly (perhaps sharing that you’re struggling with a task with a coworker), you have the opportunity to see if that changes the way others act toward you.

These cognitive-behavioral strategies are so effective for nudging personality because (again) personality is literally your characteristic way of thinking and behaving. Consistently making changes to your perspective and actions can lead to lasting habits that ultimately result in crafting the personality you desire.

Be who you want

The bottom line is that your personality isn’t a box—it’s a starting point. When you stop telling yourself, “I’m just like this” and start asking, “Who do I want to become?” you open the door to intentional growth. And your dreams can be the roadmap for the traits you choose to develop.