“If personality is stable, can we really change?” This is one of the most common, and most misunderstood, questions in personality science. Current research consistently shows that personality traits become relatively stable in adulthood. By our mid-20s and beyond, our broad behavioural tendencies tend to show consistent patterns over time. At first glance, that can feel limiting. If our personality stabilises, does that mean we are locked into who we are?

Most personality conversations often start in the same place: “That’s so me.” Recognition is powerful. It creates insight. It often creates relief. Sometimes it creates laughter. But awareness alone doesn’t change performance. Understanding your preferences is helpful. Understanding how those preferences influence behaviour and how that behaviour affects others is what drives growth. That’s where personality becomes commercially relevant.

When organisations choose a personality tool, one of the first questions is often, “Is it easy to understand?” That makes sense. If people cannot grasp the model quickly, it won’t travel far inside a business. But there is a more important question sitting underneath that one: Does it measure personality the way personality actually exists? Because how we measure something shapes how we interpret it. And how we interpret it shapes how we develop it.

Most people see a big number and think: Great. That must mean it’s good. But here’s the question few people ask: Good at what? Because a high reliability score does not automatically mean a model is useful, predictive, or even particularly insightful. It simply means the items hang together consistently. And consistency, on its own, is not the same as value.

One of the unintended consequences of personality work is that what begins as insight can quietly become identity. At first, this can feel empowering. Personality language gives people words to describe themselves. It creates recognition. It reduces confusion. It can build self-efficacy around ‘knowing self’.