Survival of the Steadiest

When I first studied psychology some years ago, personality typing was really big. Students would fill out batteries of tests and inventories and come away with tidy answers to the Big Question: Who Am I? One popular personality test, based on the thinking of the Swiss psychoanalyst Carl Jung, told me I was The Protector, which meant that I tended to let my feelings trump my reasoning. As an angst-ridden young adult, I was okay with that identity. I wasn’t quite as happy with being a Type A, which meant I was driven and competitive and hostile and would probably die young.

A lot of this was just parlor game. What did it mean that I shared my basic temperament with Louisa May Alcott and Robert E. Lee? But the clear message we all took away from this constant labeling was unmistakable: Who you are — your identity, your essence — is a crucial, one-time roll of the dice. Childhood experience might do some tinkering around the edges, but by early adulthood the collection of traits that defined you was pretty much fixed for life — or death, as the case may be.

Most psychologists don’t think so fatalistically about personality anymore. Indeed, quite the opposite, and for good reason. Many studies over many years now have shown that personality is quite malleable, and that it changes — or at least can change — not only in childhood, but in young adulthood, middle age, even when we are old and supposedly set in our ways. Psychologists still believe — more than ever — that personality is related to health and mortality. But most now contend that age-related shifts in our sense of identity are just as important as our genetic legacy. Here’s how it works.

First, forget those old categories. There is broad consensus today that personality is an amalgam of traits called the “Big Five”: extraversion, agreeableness, conscientiousness, emotional stability, and openness to experience. Each of these broad measures can be broken down into smaller ones, but in general this taxonomy appears to take in most of what we think of as personhood. When you think of someone as basically “steady” or “flaky” or “gloomy” or “daring,” what you’re really doing is unconsciously taking a measure of these five traits and crunching them together.

So what makes a healthy personality? Psychologists have been studying this important question, and at least two of these five traits appear to be directly related to physical well being and longevity: emotional stability and conscientiousness. More to the point, wellness is linked to changes in these traits over time.

Consider emotional stability. Or, rather, its polar opposite, which psychologists call neuroticism. Neuroticism is the tendency toward hand wringing and negative thinking. People with a heavy does of neuroticism don’t handle stress well at all, and are often anxious and moody. Such negativity has been linked to increased mortality in a number of studies, but for Purdue University psychologist Daniel Mroczek this finding raised as many questions as it answered. Does it follow that this inherited trait is a death sentence? Or can people with this propensity change their destiny?

Mroczek decided to explore this idea. Using a standard measure of neuroticism, he tracked more than 1,600 men over 12 years, recording not only how neurotic they were at the start but also whether they got more or less neurotic over time. He also looked at mortality risk for these same men over an 18-year span. As reported in the May issue of the journal Psychological Science, being more neurotic than average was not enough in and of itself to predict an early death. But being a worrier and getting more stressed out over time was a ticket to an early grave. In other words, these men — all middle age or older to begin with — didn’t grow old gracefully. They got more and more fretful, and this downward spiral increased their risk for dying, mostly from cancer and heart disease.

That’s the bad news. The good news is that men with a fretful temperament, if they managed for whatever reason to chill a bit over time, had survival rates similar to those of emotionally stable men. This finding jibes with other life-span research on conscientiousness and health. Brent Roberts of the University of Illinois has done several studies showing that the cluster of traits comprising conscientiousness — orderliness, industry, reliability, conventionality, and so forth — not only can and do increase over the entire lifespan, but these changes are directly related to improved health and longevity.

Why? Well, there are a couple likely reasons. First, conscientious people create life paths for themselves that contribute to better health. That is, they are more successful in their careers, earn more money, have more stable families, and socialize more — all factors known to be linked to health. For example, Roberts tracked college-educated women from age 21 to age 52, and found that women who had been more conscientious in college were less likely to divorce and had more children than women who had been less centered. Other studies have linked conscientiousness to job stability and job satisfaction.

In addition, industrious and reliable people simply do fewer stupid things. They don’t smoke as much, drink as much, drive as fast, have sex with the wrong partners — all those things that we know kill us. This may seem self-evident at first, but what’s not is the link between healthy living and changes in personality. It appears that young adults especially start trying on certain roles — parent, reliable employee — and “watching themselves.” If they like what they see (and they often do), they in effect add a trait to their psychological repertoire that wasn’t there before. They change their opinion of themselves. So in a sense, conscientiousness shapes experience, which in turn helps people mature and become more solid. This is hopeful news for those parents despairing over their slacker teenager.

The effect of conscientiousness on longevity is not trivial. Indeed Roberts estimates that being a responsible person is as powerful as cardiovascular disease in determining how long we live. Psychologists have long suspected that a single common psychological trait may underlie all healthy choices, and conscientiousness is emerging as a strong candidate for that H factor. If so, simply acting “as if” you are solid and centered may be one way to a long, healthy life.