The pandemic may have caused people to become more neurotic and less agreeable, open and conscientious, the study found.

Editor’s Note: Sign up for CNN’s Stress, But Less newsletter. Our six-part mindfulness guide will inform and inspire you to reduce stress while learning how to harness it.

CNN  — 

Covid-19 changed a lot – how we socialized, where we went, and even what work looked like. A new study shows the pandemic may have changed our personalities as well.

Psychologists have long believed that a person’s traits stayed pretty much the same, even in the wake of stressful events. But by looking at pre-pandemic levels of neuroticism, extraversion, openness, agreeableness and conscientiousness and comparing that to data collected in 2021 and 2022, researchers found notable personality changes among the United States population, according to the study.

“The pandemic was an unprecedented opportunity to see how a collective stressful event may impact personality,” said lead study author Angelina Sutin, a professor of medicine at Florida State University.

Extraversion, agreeableness and conscientiousness all declined in the US population in the years following the start of the pandemic, particularly in young adults, according to the study, published Wednesday in the journal PLOS One.

Why were younger adults more impacted? We can’t know for sure, Sutin said, but there are theories.

“Personality is less stable in young adults,” Sutin said. “But then at the same time, the pandemic disrupted what young adults are supposed to be doing. They’re supposed to be in school or starting their careers or transitioning into careers. They’re supposed to be going out and forming relationships.”

The results didn’t hold true for each person — it was a look at a population trend, so it’s no surprise if you don’t see that same change in yourself or those closest to you, Sutin said.

There are some caveats to the data as well, said Brent Roberts, a professor of psychology at the University of Illinois at Urbana-Champaign who was not involved in the study. Since there wasn’t a control group and other explanations were not examined, he said it’s hard to say for sure whether the pandemic caused these changes.

Behind the findings

Researchers collected the data from the more than 7,000 people ages 18 to 109 who participated online in the Understanding America Study, comparing how they responded to questions before February 2020 versus later that same year and then again in 2021 or 2022, according to the study.

They examined the data through the five-factor model, which hypothesizes that the various personality traits can be attributed to one of five overarching qualities: neuroticism, extraversion, openness, agreeableness and conscientiousness.

Over the entire population they examined, researchers found a declining trend in neuroticism in 2020, but the changes were small, according to Sutin.

Once they took 2021 and 2022 data into account, researchers saw a more significant decrease in extraversion, openness, agreeableness and conscientiousness. The change was big enough to equal about a decade of change, according to the study. Neuroticism also increased over this time.

That is especially significant considering how essential those traits are, Sutin said. Conscientiousness is important for academic and work outcomes, as well as relationship and physical health, she added.

“The increased neuroticism and decreased conscientiousness would mean that this cohort would be more vulnerable to mental and physical health problems,” Roberts said. “Although, given the modest effect sizes, these effects would be too subtle to see at the level of an individual and would more likely only be seen in aggregate, population-level analyses such as those done by epidemiologists.”

Questions remain

A society that is less open, agreeable and conscientious may not sound promising, but experts say there’s still more work to do to determine how these findings may impact the future.

Although researchers noted changes, they cannot yet say how long the difference in personality might last or whether it will see a swing back, Sutin said.

The takeaway, Roberts said, is that “personality, while more consistent than changing, is not fixed and can respond to changes in the environment.”

And since there were changes both in society and the ways individual people functioned, it’s clear the pandemic was difficult for everyone, he added.

“In other words, (people) are not crazy, it’s been a hard few years on all of us. So much so that there has even been a small effect on our personalities,” Roberts said.