Is Your Personality Plastic Or Set In Plaster?

What's on your list of New Year's resolutions? Are you determined to pay off your credit card debt? Start taking piano lessons? Or maybe you have more ambitious personal goals. Perhaps you intend to retire a bad temper. Maybe you're determined to slow down and smell the roses.

Most people find it hard to stick to a pledge to lose 10 pounds. So what are the chances of transforming your very self?

Psychologists and therapists have been debating that question for 20 years, trying to determine whether adults can alter basic tendencies and traits, and at what point their personality becomes permanently fixed - if it does.

They have yet to agree even on the definition of personality, which turns out to be as slippery as the notion of the soul. Psychologists have defined personality in a variety of ways - as the self, as a repertoire of characteristic behaviors, as temperament, as a series of traits, or as the entire life of the individual.

Researchers studying personality generally select a few traits - independence, agreeableness, shyness, competence, for example - and then measure how those traits change, or remain constant, over time. Most studies show more consistency than change.

Set in plaster?

Paul Costa and Robert McCrae, psychologists at the National Institute on Aging in Baltimore, believe personality is "set in plaster" by early adulthood. In a paper presented at the American Psychological Association conference in August, Costa and McRae wrote, "Somewhere between the ages of 21 and 30, personality appears to take its final, fully developed form."

Avshalom Caspi, a psychologist at the University of Wisconsin, has published several papers that argue that basic personality emerges during childhood and then remains remarkably stable. In a study of girls who started menstruating much earlier than their peers - an "off-time" event that is widely considered to be stressful - he showed that girls who had behavioral problems earlier in childhood had more problems during adolescence. Analyzing data from this and several other studies, Caspi maintains that stressful life events tend to accentuate - not change - basic personality traits.

But other research supports the idea that personality can change throughout life. Ravenna Helson, a research psychologist at the Institute of Personality and Social Research at the University of California at Berkeley, agrees that personality is "a relatively enduring structure," but she also says that "under some circumstances, it might be expected to change."

Helson's long-term study of 100 women from the classes of 1958 and 1960 of Mills College in Oakland, Calif., and their husbands found changes in independence, dominance and self-esteem well past the age of 30. The changes, she found, were less pronounced in the men.

What psychotherapists say

Psychotherapists, who would seem to be in the business of helping people change, also join in the debate over whether basic personality changes are possible. Eric Harris, a psychologist in private practice in Lexington, Mass., says he tends to agree with the idea that personality is "relatively immutable."

"The myth of transformation gets in people's way" by giving them unrealistic expectations, he said. According to Harris, the goal of therapy is to help people better understand their personalities and adjust their behavior accordingly.

Eleanor Counselman, on the other hand, believes that people can change, and that therapy can help the process. "I'm not saying it's easy," said Counselman, who has a private practice in Belmont, Mass. "In fact, I think it's really hard. But it would be a very depressing world if you thought that once you hit 30 or 40, that's it - you're cast in a mold."

Stability has its benefits

Robert McCrae, Costa's associate and co-author of their paper entitled, "Set like Plaster: Evidence for the Stability of Adult Personality," is used to hearing that his position is depressing.

People "think about being stuck with what they don't like about themselves," but stability has its benefits, too, said McCrae, whose paper will appear in a forthcoming book titled "Can Personality Change?"

"People don't think about what they like about themselves," he said. "If right now you are a well-adjusted, outgoing, creative person, that will probably continue to age 90. It means when you get old, you won't necessarily get depressed and socially withdrawn."

For their research, McCrea and Costa looked at five general traits: neuroticism, extraversion, openness, agreeableness and conscientiousness. Their conclusions, based on their own work and on studies by other psychologists, is that after age 30, any changes in these basic characteristics are statistically insignificant.

McCrea and Costa did find small declines in neuroticism, extraversion and openness over time, and modest increases in agreeableness and conscientiousness. However, because most of the data on change are based on one-shot studies of different groups of people, rather than on longitudinal or long-term studies of a single group, the researchers say, there may be "alternative explanations" for the findings.

For example, McCrea and Costa theorize that the higher levels of agreeableness among older people may be due to the fact that very disagreeable people are more prone to coronary disease; they die, and thus alter the nature of the group being studied.

Costa and McCrea cite Ravenna Helson's 30-year study of Mills College graduates, one of the few long-term studies, to bolster their claim that the most dramatic personality changes occur between the ages of 20 and 27. That is a period characterized by change, but Helson found significant changes in later adulthood, as well. She notes that the biggest increase in assertiveness occurred between the ages of 30 and 43 and was especially marked among women who worked outside the home.

The role of social climate

Helson says many researchers tend to ignore the impact of social climate and demographic factors when studying change among adults. "The Mills study showed that participation in the labor force made a big difference in the personalities of the women," she says. Helson also says that her own research shows that "everybody changes in some ways."

She found increases in independence, for example, across the board in the sub-groups of women, although traditional homemakers showed the smallest increases.

Helson does not challenge the notion that personality is stable but, she says, "To say that you have reliable measures of stability doesn't contradict the idea that people can change. Stability of personality and change are unrelated to each other."

To illustrate her point, she says, "If you have five children in five grades and each goes up a grade every year, the stability is the same," but the change is also dramatic. "We don't seem to understand or remember that long enough to keep from feeling there is a conflict."

Harris would probably agree with McCrae's and Costa's conclusion that "People surely grow and change, but they do so on the foundation of enduring dispositions."

Added Harris, "There are limited parameters of alteration." But that, he says, shouldn't be cause for dismay. "It's hard enough to be yourself. If people can learn to be the best person they can be, that is worth working for."

And this is especially true when it comes to New Year's resolutions, he says. Resolutions can be productive if you recognize "who you are and what is possible, and thus have reasonable goals and expectations." But he cautions that trying to become a different kind of person, "leads to spurts of trying hard, discouragement, depression, a sense of failure and self-loathing."

In the end, says one therapist, this whole debate may be a semantic one.

"I think it's hard to distinguish between core personality and what's going on in your life," says Counselman. "In my practice, I have seen people who look terribly rigid, and then, through a change of life circumstances, such as when the last child goes off for college, I see much greater flexibility.

"They really look as though they've changed. Whether it's real personality change or not," she says, "it really doesn't make any difference."