May 12, 2003 -- Despite the popular theory that personality is genetically "set in plaster" by early adulthood, new research suggests the proverbial old dog can learn new tricks -- and mostly for the better.
As people reach middle age and beyond, the study shows, they tend to care more about their work, responsibilities, and those in their lives. But they also become less open to meeting new people, and women become less neurotic and extroverted.
These findings, published in the May issue of the Journal of Personality and Social Psychology, were reached after analyzing self-reported answers to an online questionnaire completed by some 132,000 Americans and Canadians between ages 21 and 60. They rated themselves on personality traits known by psychologists as the "Big Five": conscientiousness, agreeableness, neuroticism, openness, and extroversion.
"We were somewhat surprised by our findings," says lead researcher Sanjay Srivastava, PhD, psychologist at Stanford University. Though previous research has suggested that personality changes less and less over time, the researchers found that certain personality traits change gradually but consistently throughout life -- and on average, people are getting better as get older.
His study adds to evidence that personality may not solely result from biology, but changes over time as the result of life stages, experiences, social environment, and gender. And Srivastava tells WebMD that it should offer reassurance to people worried about aging being a process of decline. "As you get older," he says, "you can get better ... at least in certain traits."
The researchers found that conscientiousness -- being organized, disciplined, and well-planned, especially at work -- increased most strongly in the 20s for both men and women, and these personality changes slowed by age 30 but didn't stop. Agreeableness -- being warm, generous, and helpful -- accelerated most in the 30s in both men and women and climbed more slowly in the 40s, with women recording higher overall levels. Meanwhile, rates of neurosis tended to decrease with age in women but didn't change much in men. And both sexes had small declines in their levels of openness, but split on extroversion -- women became less gregarious with age while men became slightly more outgoing.
Are these simply the results of the added responsibilities that come with building a career and family? "One could argue that as you get more into adulthood, you have new responsibilities and that's why you are more conscientiousness. You have a family, so you're more agreeable," Srivastava tells WebMD. But the cause of why these traits change wasn't examined in his study. Srivastava says biology may be programmed to make people adapt better to life's new chapters.
Srivastava notes that "openness" is subject to interpretation: People may not be really less open as they age; they may just not choose to meet new people and instead spend their time with already established loved ones.
Two experts not connected with the study agree that personality changes throughout life, but they question how the study was conducted. It did not follow the same people over time, but rather compared self-perceived ratings among different people in different age groups.
"When you compare different age groups at the same time, there's still doubt there," says Bernardo J. Carducci, PhD, director of the Shyness Research Center at the University of Indiana and the author of a textbook on personality. "You're essentially comparing apples with oranges on a specific date. What they really need to do is compare apples with apples with apples over time, and oranges with oranges with oranges over time."
Still, Carducci says he believes the study would be a useful tool in helping psychologists better learn about the evolution of personality via the Internet, a new medium for gathering scientific data in which people may be less likely to lie about their self-perceptions than in a personal evaluation.
Another researcher says good research suggests that personality changes throughout life. "People tend to have more integrity and put more emphasis on fulfilling their responsibilities and doing what they say they'll do," says psychologist Robert Hogan, PhD, who has devised a similar assessment questionnaire and written several books on personality. But he says a better way of evaluating someone's personality is to have the people answer the questionnaire, and then validate their answers with others who know them. "People sometimes see themselves differently than others see them."
Hogan, a spokesman for the American Psychological Association, says that his research has produced similar patterns of change on four of the Big Five traits, but he disagrees that people become more agreeable as they age. "Most research shows that as people get older, they are not more agreeable -- they don't care as much," he tells WebMD.
The key to these improvements may be the result of attaining a better sense of identity. "The changes noted in the other traits can largely be attributed to attaining more of a sense of identity as one gets older. A large part of these positive changes reflected in this and other studies stems from knowing who you are and what you stand for. And that often occurs in your 30s."