Do people change? The truth about personality over time

Have you ever wondered if people truly change? After attending my 40-year high school reunion, I reflected on this question. As a psychologist, I’ve spent years studying human behaviour, and what I witnessed that night was both surprising and affirming.

Some classmates were instantly recognizable—their mannerisms, humour, and overall vibe felt unchanged. Others, however, had transformed in ways I would never have predicted. Some had mellowed, while others had grown more outspoken. Some had aged in a way reflecting years of experience and wisdom, while others seemed frozen. So, do people genuinely change, or do our basic personalities remain stable?

The Science of Personality Stability

Psychologists have long debated how much personality shifts over time. Research suggests that while people can grow and evolve, their core traits remain relatively stable. The Big Five personality traits—openness, conscientiousness, extraversion, agreeableness, and neuroticism—tend to stay consistent throughout adulthood.

At my reunion, I saw this play out in real life. The class clown still cracked jokes, the natural leader commanded attention, and the quiet observer preferred listening. And yet, beneath these familiar traits, there was also something different—more wisdom, resilience, and in some cases, an entirely new perspective on life. Some who had been insecure in high school now carried themselves with confidence. Others who once seemed carefree had been shaped by the trials of life, showing a depth they hadn’t before.

So, If We Do Change, How Does It Happen?

While our basic temperament may not shift dramatically, true transformation is possible—but it doesn’t happen by accident. People who make significant personal changes often share these three traits:

1. We Experience a Defining Moment

Major life events—parenthood, illness, loss, career shifts—can trigger deep self-reflection. A once-reckless friend might become responsible after a crisis, or a rigid thinker might become more open-minded after travelling the world. Hardships and successes alike serve as catalysts for growth.

2. We Choose Growth Over Comfort

Real change is intentional. People who evolve don’t just let life happen to them—they actively seek self-improvement. They go to therapy, read, reflect, and challenge themselves. Change isn’t just about aging; it’s about effort. Small, consistent choices over time lead to profound transformation.

3. We Surround Ourselves with the Right Influences

The company we keep shapes who we become. A growth-oriented environment fosters change, while toxic or stagnant relationships keep us stuck in old patterns. Those who genuinely transform often credit key mentors, friends, or even challenging relationships for their evolution. Supportive communities and new perspectives can accelerate personal growth.

The Bottom Line

If my high school reunion taught me anything, it’s that personality isn’t set in stone—but it doesn’t change without reason. Growth happens when we embrace challenges and make conscious choices to evolve. If you want to change, time alone won’t do it. You have to decide to make it happen.