Do people’s personalities change with age?

But it makes that the temper change during these decades. Over all these years, our personalities have changed, but slowly. “It’s a subtle thing,” Roberts said. It is hard to see on a 5 to 10 years’ scale, but in the long run it is obvious. In 1960, psychologists surveyed more than 440,000 college students -- 5 percent of the nation’s students at the time. The students answered a variety of questions, from how they responded to emotional problems to how effectively they completed tasks. Fifty years later, the researchers tracked 1952 of the participants and did the same survey. The findings, published in the 2018 issue of the Journal of Personality and Social Psychology, found that participants scored higher in their 60s than in their teens on measures of calmness, confidence, leadership and social sensitivity.

Longitudinal studies have found similar results. Personality will become “excellent” over time. Psychologists call this the “maturity principle.” As people get older, they become more outgoing, more emotionally stable, more pleasing, and more responsible. In the long run, these changes are usually obvious.

Some individuals may change less than others, but in general, the principle of maturity applies to everyone. This makes it harder for us to detect changes in our personality -- your personality does not change as much as our overall personality changes compared to your peers, because everyone else is changing just like you. “There’s good evidence that average self-control at 30 is better than average self-control at 20,” Donnellan said. “At the same time, people who are relatively self-controlled at 18 are tend to relatively self-controlled at 30.”

So why have we changed so much? The evidence suggests it was not a dramatic life event, like a marriage, the birth of a child or the loss of a loved one. In fact, Donnellan says, some psychologists have pointed out that when you deal with these situations with your personality features, these big events reinforce your personality.

Roberts says that changing the expectations we place on us - like adjusting to college, working, starting a family - requires us to slowly adjust, like putting on a pair of shoes. “with the time passing by, in many situations in your life, you will be asked to change your style of doing things,” he said. “There is no manual for how to act, but there are very clear implicit norms for how to act in these situations.” Then we adapt to the environment.

Whether it is a revelation, unsettling or hopeful matter depends on how you look at it. With the time passing by, personality does change, step by step, throughout -- like a tectonic plate shifting, but not an earthquake. Robert said, “this introduced the question: How much have we changed over the course of our lives?”