13 Personality Change
Earlier in the course, we examined personality development across the life course. We learned that personality traits are not perfectly fixed. People tend to become more stable in their relative standings as they get older, and there are average developmental trends in traits such as agreeableness, conscientiousness, and emotional stability. But that still leaves a more personal and practical question: can people change their personality in the specific ways they want to change?
This is a tricky question because the answer depends on what we mean by change. If by change we mean becoming a completely different person overnight, then the answer is almost certainly no. Personality traits are relatively stable summaries of typical patterns of thoughts, feelings, and behaviors. They do not usually flip all at once. But if by change we mean shifting the average pattern of thoughts, feelings, and behaviors over weeks, months, or years, then the answer appears to be yes. The more difficult question is how this happens, how much change is possible, and what conditions make change more likely.
In this chapter, we will examine volitional personality change, which refers to intentional efforts to change one’s own personality traits. We will also examine evidence from clinical interventions, because psychotherapy and other structured interventions may change personality even when personality change is not the explicit goal. Along the way, we will keep returning to a basic idea: traits are broad descriptions, so changing a trait probably requires repeatedly changing the smaller state-level thoughts, feelings, and behaviors that make up the trait.
Many People Want to Change Their Personality
Before asking whether people can change their traits, it is worth noting that many people want to. If you ask people whether there is some aspect of their personality they would like to change, most people can think of something. This should not be surprising. Personality traits are tied to many outcomes people care about, including relationships, work, health, and emotional well-being.
The most common desired changes also make intuitive sense. Across studies, people often report wanting to become more emotionally stable, more conscientious, more extraverted, and more agreeable (Baranski et al., 2021; Hudson & Fraley, 2015). In everyday terms, many people would like to feel less anxious or emotionally reactive, become more disciplined and organized, feel more socially confident, or be kinder and more patient with other people. These desired changes overlap with the maturity principle from the development chapter, which described the average tendency for people to become more agreeable, conscientious, and emotionally stable with age.
However, wanting to change is not the same thing as changing. Lots of people want to exercise more, sleep better, save money, or study earlier for exams. The wanting is real, but it does not automatically produce the behavior. Personality change has the same problem. The question is not only whether people prefer a different trait profile. The question is whether they can repeatedly think, feel, and behave in ways that are different enough, and consistent enough, to eventually shift their average tendencies.
From Personality States to Personality Traits
A useful way to think about personality change is to distinguish between personality states and personality traits. A personality state is a temporary pattern of thinking, feeling, or behaving in a particular moment. For example, a person might behave assertively during a group task, conscientiously while studying, or (dis)agreeably during a conflict. A personality trait is a broader summary of how often and how strongly a person tends to show those states across many situations and over time.
This distinction makes personality change seem less mysterious. To become more extraverted, a person does not need to magically acquire an extraversion substance inside the brain. They would need to spend more of their life in extraverted states: initiating conversations, expressing enthusiasm, approaching social opportunities, or practicing social confidence. To become more conscientious, a person would need to spend more of their life in conscientious states: planning, following through, organizing tasks, and resisting impulses that interfere with goals.
The basic premise of many personality change interventions is that lasting trait change can be produced by modifying state-level thoughts, feelings, and behaviors over extended periods of time (Hudson, 2021; Hudson et al., 2021). This does not mean that every temporary state becomes a trait. Acting outgoing one time will not make someone an extravert. Studying carefully for one exam will not make someone highly conscientious. The idea is that repeated states, practiced over time, may gradually become easier, more automatic, and more incorporated into the person’s identity.
Figure 13.1 summarizes one way to think about this process. Interventions do not directly reach into the mind and rewrite a personality trait. Instead, interventions are supposed to change what people repeatedly do. The most immediate bottleneck is intervention adherence, which means whether the person actually follows through with the activities, challenges, or behavioral practices that the intervention requires. If adherence is low, then the intervention has little opportunity to change the person’s recurring states. If adherence is high, then those recurring states may eventually contribute to identity changes, biological changes, and trait change.
This is why personality change is not just a matter of insight. Insight may help, and motivation may help, but the central mechanism in this framework is repeated change in thoughts, feelings, and behaviors. If the behavioral pattern never changes, then there is not much for the trait summary to summarize differently.
Participant Attributes That May Affect Change
People differ in how likely they are to benefit from a personality change intervention. One obvious factor is motivation. A person who strongly wants to change may be more willing to practice new behaviors, tolerate discomfort, and continue when progress is slow. Motivation may be especially important because many personality change goals require doing things that initially feel unnatural. A shy person trying to become more extraverted may need to start conversations that feel awkward. A disorganized person trying to become more conscientious may need to build routines that feel tedious.
Self-regulation is another important factor. Self-regulation refers to the ability to monitor one’s behavior, inhibit competing impulses, maintain attention to goals, and adjust when things are not working. This matters because personality change is not just a single decision. It requires many small decisions across time. A person might decide in the morning to be more patient, more organized, or more outgoing, but the relevant test happens later when they are tired, stressed, busy, or distracted.
A third factor involves beliefs about change. Some people hold a relatively fixed mindset about personality, where they believe personality is basically set and cannot change much. Other people hold a growth mindset, where they believe personality is fluid and can change. It is easy to imagine that a growth mindset should make personality change more likely. If people believe change is possible, perhaps they will try harder and persist longer.
The evidence is less supportive of this idea than you might expect, however. In studies of emerging adults, beliefs about whether personality can change did not consistently predict actual trait change (Hudson et al., 2021). This does not mean beliefs are irrelevant in every possible context. It does mean that merely believing personality can change is not enough. A person can believe change is possible and still fail to follow through. Likewise, a person can be skeptical about personality change and still change if their daily behavior is repeatedly altered by an intervention, social role, or environment.
This finding is useful because it pushes us away from overly simple slogans. Growth mindsets may be encouraging, but personality change probably depends more on what people repeatedly do than on whether they endorse a general belief that change is possible.
Intervention Attributes That May Affect Change
The design of the intervention also matters. A vague goal such as ‘be more conscientious’ or ‘be less anxious’ may express a real desire, but it does not give the person much guidance. What should they do at 9:00 AM tomorrow? What should they do when a friend texts them, when they sit down to study, or when they feel irritated? Personality traits are broad summaries, but interventions need to operate at the level of concrete states and behaviors.
One important feature is concreteness. A concrete intervention translates a broad trait goal into specific, detailed actions. For example, instead of simply trying to be more organized, a person might decide to write a prioritized task list before bed each night, set a reminder for one recurring obligation, or spend ten minutes clearing a work space before starting homework. The point is not that these particular examples work for everyone. The point is that a concrete plan specifies what the person is supposed to do.
A second feature is feasibility. A goal can be concrete but unrealistic. If a person who currently avoids nearly all social interaction sets the goal of attending three large social events every week, the plan may fail because it is too demanding. Feasible interventions are challenging enough to create change but realistic enough that the person can actually follow through. This matters because failed plans can reduce motivation and make the person less likely to continue.
A third feature is intensiveness. An intervention that happens once is unlikely to produce lasting change unless it triggers repeated practice afterward. Personality traits summarize average patterns, so the intervention needs enough repetition to affect those averages. This is why many interventions involve repeated challenges, prompts, reminders, or exercises over weeks or months.
A fourth feature is duration. Even an intensive intervention may not last long enough for new behaviors to become habitual or identity-relevant. Duration refers to how long the intervention continues. Longer interventions are not automatically better, because people may stop adhering if the intervention becomes exhausting or inconvenient. But in general, changing a trait-like pattern should require sustained practice over time rather than a single burst of effort.
Evidence from Psychotherapy and Clinical Intervention
One source of evidence for personality change comes from psychotherapy and clinical interventions. These interventions are often designed to reduce distress, treat symptoms, or improve functioning, not necessarily to change personality traits. Even so, they may alter the recurring thoughts, feelings, and behaviors that personality questionnaires measure.
A meta-analysis of intervention studies found that personality traits can change during psychological and clinical interventions, with especially notable changes in emotional stability (Roberts et al., 2017). This is important because emotional stability is closely related to neuroticism, the tendency to experience frequent or intense negative emotions. If therapy reduces patterns of anxiety, worry, emotional reactivity, avoidance, or depressive thinking, then it is not surprising that people may also appear to become more emotionally stable on personality measures.
Psychotherapy is therefore a strong reminder that personality is not sealed off from the rest of psychology. The same processes that change symptoms, coping strategies, relationship patterns, or daily routines may also change trait-relevant patterns. Still, we should be cautious. When a person’s depression or anxiety improves, their responses to personality items may change partly because they are in a different emotional state. Distinguishing true trait change from symptom change, response bias, or temporary state change is difficult. The evidence suggests that intervention-related trait change is possible, but it does not mean that every therapy client changes personality in the same way or to the same degree.
Evidence from Volitional Personality Change Studies
Research on volitional personality change asks a slightly different question: when people intentionally try to change their traits, do they move in the direction they want to move? Early studies suggest that they often do, at least to some degree. For example, people who reported wanting to increase a trait such as extraversion tended to show increases in that trait over time (Hudson & Fraley, 2015). This pattern is encouraging, but it also leaves open an important question: what are people doing that produces the change?
One answer comes from research on behavioral change challenges. In these studies, participants selected weekly challenges designed to pull their thoughts, feelings, and behaviors in line with their desired traits. For example, a challenge aimed at extraversion might involve initiating a conversation; a challenge aimed at conscientiousness might involve completing a task before a deadline. The key finding was that merely accepting challenges was not enough. Completing the challenges predicted trait change over time (Hudson et al., 2019).
This finding fits neatly with the state-to-trait logic described earlier. A challenge only matters if it changes what the person actually does. Accepting a challenge is a declaration of intent. Completing a challenge is a new behavior. Across enough repetitions, those new behaviors may accumulate into a different average pattern.
The evidence is not uniformly simple. Some interventions work better for some traits than others, and some attempts may produce weak or even unexpected results. Openness, for example, has sometimes been more difficult to change in a straightforward way than traits like extraversion, conscientiousness, agreeableness, or emotional stability. This should not be surprising. A personality trait is not a single behavior. It is a broad, heterogeneous construct. Some parts of a trait may be easier to practice than others, and some interventions may target only a narrow slice of the broader trait.
More recent intervention studies have used digital tools to support personality change. In one randomized controlled trial, adults used a smartphone-based coaching intervention designed to support desired trait changes over several months (Stieger et al., 2021). Participants receiving the intervention showed greater changes than a waitlist control group, and some changes were also visible to people who knew the participants. This provides stronger evidence than simple correlational studies, because random assignment helps rule out some alternative explanations. But even randomized interventions do not answer every question. We still need to know how long changes last, which components are most important, and whether changes produce improvements in life outcomes.
How Much Change Is Possible?
The evidence reviewed in this chapter supports the possibility of personality change, but it does not support unlimited change. Traits are relatively stable for a reason. They are shaped by many interacting factors, including genetics, biological systems, developmental history, habits, relationships, social roles, and environments. A short intervention can push on some of these factors, but it cannot instantly replace all of them.
There are also limits in measurement. Many personality change studies rely on self-reports. If people know they are trying to become more extraverted or more conscientious, they may later interpret themselves through that goal. This does not mean self-reports are useless, but it does mean we should be skeptical of overly dramatic conclusions. Informant reports, behavioral measures, long follow-up periods, and randomized designs all help, but no single study design solves every problem.
Another issue is durability. A person might show meaningful change during an intervention but drift back toward previous patterns after the intervention ends. This is common in behavior change more generally. A structured environment can make new behaviors easier, but when the structure disappears, old habits and old situations can return. Durable personality change likely requires either continued adherence, new habits that persist without effort, or environments that keep reinforcing the new pattern.
Finally, personality change is not automatically improvement. Higher levels of a socially desirable trait can still have costs in some contexts. More conscientiousness may come with rigidity or stress. More agreeableness may make it harder to set boundaries. More extraversion may be useful in some environments and exhausting in others. Personality change should be evaluated in relation to goals, contexts, tradeoffs, and well-being, not treated as a simple march toward the highest possible score on every desirable trait.
Closing Thoughts About Personality Change
The main conclusion from this chapter is neither ‘personality is fixed’ nor ‘you can become anyone you want by deciding hard enough.’ Both claims are too simple. Personality traits are stable enough that change usually requires sustained effort, repeated practice, and supportive contexts. But they are also malleable enough that interventions, therapy, social roles, and deliberate behavioral practice can shift them.
The state-to-trait perspective gives us a practical framework. If traits describe average patterns of thoughts, feelings, and behaviors, then changing a trait requires changing those patterns repeatedly over time. A desire to change may start the process. A growth mindset may make the process feel more possible. But the crucial step is follow-through: repeatedly enacting the states that are consistent with the desired trait until they become more typical.
This framework should also make us skeptical of magical thinking about personality change. A new label, a motivational quote, or a one-time insight is unlikely to transform a broad trait. Personality change is more mundane than that. It is built from repeated behaviors, recurring situations, feedback from others, and gradual shifts in identity and habit. That may make personality change sound less dramatic, but it also makes it more scientifically understandable.
References
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Hudson, N. W. (2021). Dynamics and processes in personality change interventions. In The handbook of personality dynamics and processes (pp. 1273-1295). Academic Press.
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