Every few years, we all say it: “I’ve changed.”
Maybe you’ve mellowed out, become more confident, or finally stopped texting your ex. But have you really changed, or have you just learned to behave differently?
Psychologists have been wrestling with that very question for over a century now. Are we essentially the same people across time, or are we constantly rewriting who we are?
It turns out, the answer is both.
Personality is surprisingly stable, but it’s not immovable. Much like a river, it keeps its general course while the water itself is always flowing.
Let’s explore what science (and a few famous psychologists) have to say about whether we ever truly change.
The Roots of the Debate
Early psychology was obsessed with this question.
Sigmund Freud believed personality was largely fixed by early childhood.
In his view, once your id, ego, and superego had hashed out their lifelong turf war, you were basically set. Later experiences might tweak your behavior a bit here and there, but the deep structures (that is, your psychic “architecture”) stayed stable.
Then came Erik Erikson, who argued that we keep developing through eight psychosocial stages, from infancy to old age.
In Erikson’s model, each stage presents a challenge (such as trust vs. mistrust, identity vs. role confusion, or integrity vs. despair), and how we resolve them shapes who we become. So, in Erikson’s view, change is both possible and necessary.
Then Carl Rogers, the humanistic optimist, took it further. He saw personality as fluid, driven by a desire for self-actualization and becoming the most authentic version of oneself.
Rogers believed that, under the right conditions (empathy, acceptance, and congruence), people can absolutely grow and transform.
Meanwhile, Albert Bandura’s social-cognitive theory emphasized the power of environment and self-efficacy. We’re not passive victims of our traits; we’re active participants in shaping them.
In short: Freud said we’re stuck, Erikson said we’re staged, Rogers said we can grow, and Bandura said, “Hold my Bobo doll. I’ll show you how!”
The Big Five and the Case for Stability
Fast-forward to modern psychology, and the Big Five Personality Traits (Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism) have become the leading framework for understanding personality.
Research shows that these traits are remarkably consistent across time, especially after early adulthood. Psychologists call this “rank-order stability”: while everyone changes a little, our relative positions compared to others tend to stay the same.
For example, if you’re more conscientious than your peers at 25, you’re likely still more conscientious at 55, even if everyone’s become a bit more responsible.
Longitudinal studies, such as the Baltimore Longitudinal Study of Aging, found that personality correlations across decades often exceed 0.6 to 0.8, meaning your adult self is statistically quite similar to your younger self.
Why so stable? Well, it’s partly biology.
Twin studies suggest that 40–60% of personality variation is heritable (Vukasović & Bratko, Psychological Bulletin, 2015). Brain structures and neurotransmitter systems (like dopamine pathways linked to Extraversion or serotonin systems tied to Neuroticism) act as biological anchors.
So yes, your personality has a kind of “default setting.”
But that doesn’t mean it’s locked!
The Maturity Principle: How We Do Change
Even if our rank order stays stable, our average levels of traits shift predictably as we age in a trend known as “the maturity principle.”
As people move through adulthood, they tend to become more conscientious (reliable, organized), more agreeable (kind, cooperative), and less neurotic (emotionally volatile).
Why is that? The short answer: life happens.
Jobs, relationships, parenting, bills, and responsibility all act as personality trainers. You simply can’t stay a reckless teenager forever; at least not if you actually want to keep your job, your marriage, or your sanity.
A major meta-analysis by Brent Roberts et al. (2006) found that these patterns hold across cultures and time: people generally “grow up” in personality terms. The study found robust, predictable increases in Conscientiousness and Agreeableness and declines in Neuroticism from adolescence through middle age.
So, it’s not that we become different people; we just kind of become more refined versions of ourselves.
Interestingly, these changes often correspond with social investment, which is the degree to which people commit to adult roles and responsibilities. As it happens, taking on a career, a long-term relationship, or parenthood tends to promote maturity-related growth.
In other words: paying bills, raising kids, and remembering birthdays might actually make you a better person!
But the maturity principle doesn’t mean everyone changes in the same way.
Some people plateau early; others experience late-life transformations. What’s consistent is the direction of change toward greater emotional stability and social harmony.
So, in a sense, personality doesn’t change much. It just learns better manners.
Personality Plasticity: The Possibility of Change
Still, the story doesn’t end with stability. Research in the last decade has shown that personality is actually more malleable than we once thought.
In a landmark study, Hudson and Fraley (2015) asked participants to intentionally try to change certain traits (like becoming more extraverted or less neurotic) over several months.
The results? People not only wanted to change; many actually did.
Therapy, mindfulness, and life transitions can also shift traits. For example, cognitive-behavioral therapy (CBT) for anxiety often reduces Neuroticism scores, while mindfulness training can increase Conscientiousness and Openness.
Psychologists call this personality plasticity, which means the capacity for adaptive change. It’s not easy or instant, but it’s real.
This aligns beautifully with Carl Rogers’ idea of self-directed growth: when people experience empathy, acceptance, and authenticity, they naturally move toward becoming more congruent and balanced.
And Bandura’s concept of self-efficacy (our belief in our ability to influence our environment) reminds us that change often starts with believing we can.
Systems and Situations: Zimbardo’s Shadow
Of course, personality doesn’t exist in a vacuum. Philip Zimbardo’s work on situational power (particularly what he called The Lucifer Effect) showed how dramatically context can shape behavior, and is sometimes enough to override stable traits.
For example, put a kind, conscientious person in a toxic system, and they might act cruelly. Place a shy person in a supportive, energizing community, and they might blossom socially.
Zimbardo’s conclusion was unsettling: even “good” people can behave badly under the right (or wrong) circumstances. But it also revealed something hopeful in the sense that environments can cultivate positive change, too.
Modern research supports this.
Long-term exposure to nurturing environments (so things like stable relationships, meaningful work, and supportive communities) can reinforce prosocial traits like Agreeableness and Conscientiousness. Conversely, chronic stress or trauma can heighten Neuroticism or dampen Openness.
In other words, the systems we build from workplaces to families to societies don’t just reflect our personalities; they help shape them.
So yes, systems can sculpt souls!
Personality as a Story: The Narrative Identity View
Traits describe what we’re like. But psychologist Dan McAdams argues that to understand who we are, we need to look at our narrative identity, which is the evolving life story we tell ourselves.
According to McAdams, people create internalized narratives that give their lives meaning and coherence. To that end, we edit, reinterpret, and reframe our experiences to fit the story we want to tell.
This means that personality change can happen through storytelling and by changing how we understand our past and envision our future.
For example, someone who once saw themselves as “a failure” might rewrite that story as “a survivor who learned resilience.” That shift in narrative can subtly reshape personality and increase that person’s optimism, confidence, and openness.
In other words, you’re not just the protagonist of your life story. You’re also the unreliable narrator and the editor-in-chief!
The Neuroscience of Change
Neuroscience also backs up what psychologists have long suspected: the brain is capable of plasticity throughout life.
Practices like meditation, therapy, and new learning experiences can alter neural pathways related to emotion regulation, attention, and self-control.
For instance, mindfulness training has been shown to increase gray matter density in the prefrontal cortex (linked to self-regulation) and reduce activity in the amygdala (linked to fear and stress reactivity).
These brain-level shifts align with measurable changes in personality traits, particularly reductions in Neuroticism and increases in Conscientiousness and Openness.
Pretty cool, right?
So while genes set the stage, experience can still rewrite the script!
The Legacy of the Stability vs. Change Debate
Alas, after a century of debate, psychologists have reached a kind of peace treaty:
- Traits are relatively stable patterns, anchored by biology.
- Behavior and identity, however, are flexible and responsive to life’s circumstances.
Modern research integrates both views. Personality is stable enough to define us, yet flexible enough to evolve in a dynamic equilibrium between constancy and growth.
This has huge implications, by the way.
In therapy, understanding which traits are more malleable helps set realistic goals. In education, recognizing developmental shifts can shape how we teach self-regulation and resilience. In relationships, it reminds us to expect evolution both in ourselves and in others.
As famous American philosopher and psychologist William James once said, “In most of us, by the age of thirty, the character has set like plaster, and will never soften again.”
Not to slam dunk on the father of functionalism, but modern science would politely disagree: the plaster may set, but it’s still warm enough to reshape… if you know how.
Tomato Takeaway
So, do we ever really change?
Yes… but not all at once, and most certainly not without effort.
Personality is both anchor and sail: it keeps us steady while allowing us to move with the wind. You might never become an entirely different person, but you can absolutely become a better version of yourself that is more balanced, more aware, and more you.
Change doesn’t mean erasing who you were. It means editing the story you’re still writing.
So go ahead and pick up the pen, starting with today’s Tomato Takeaway!
Have you noticed your personality shift over time, or do you feel like the same person you’ve always been?
Drop your thoughts in the comments below and let’s compare notes on this whole “personal evolution” thing!
Fueled by coffee and curiosity, Jeff is a veteran blogger with an MBA and a lifelong passion for psychology. Currently finishing an MS in Industrial-Organizational Psychology (and eyeing that PhD), he’s on a mission to make science-backed psychology fun, clear, and accessible for everyone. When he’s not busting myths or brewing up new articles, you’ll probably find him at the D&D table or hunting for his next great cup of coffee.