Who Says Stress Is Bad For You?

The X and Y chromosomes also play a role in how people respond to stress, though how much of one isn't clear. Men and women both experience stress as a rise in adrenaline and cortisol. What differs is their reaction. Women "are more likely to turn to their social networks, and that prompts the release of oxytocin, which mutes the stress systems," says Shelley Taylor, a psychologist at UCLA. If they're surrounded by loved ones when a stressor arises, she says, "there's some evidence they don't even show as much of the initial hormonal response." Without that response, there's less risk of long-term harm to the brain. It's a critical concept—yet it wasn't on stress physiologists' radar until the mid-'90s, when Taylor pointed out that most stress research in animals and humans had been conducted overwhelmingly on males.

Finally, there's that murky territory where genes and environment interact, with lifelong effects: the womb. It's not hard to find studies suggesting that maternal stress harms later child development. But what the evidence means, no one knows. "Project Ice Storm," a survey of nearly 150 expectant mothers who toughed out a 1998 squall in Quebec—some without power for up to 40 days—is one of the scariest studies. Late last year researchers reported that the women's children had lower-than-average IQs and language skills at age 5; they say the storm and its stress on the mothers had "significant effects [on the children] … in every area of development that we have examined." The study surveys many children in great detail, but it doesn't mean all pregnant women should panic about their stress levels (or panic about the fact that they've just panicked). An ice storm isn't the same kind of stressor that people encounter in everyday life, and the women in the ice-storm study don't necessarily represent all women. Those who were stuck in Quebec during the storm were likely some of the ones with the fewest resources. Their children may have been prone to low scores as 5-year-olds simply because they were poor.

A lot of the research on stress and infant development can be picked apart this way, says DiPietro, of Johns Hopkins. Also, she notes, "nobody ever got funded by saying stress doesn't harm babies." DiPietro herself is a rare exception. Two years ago, she showed that women under moderate stress in mid-to-late pregnancy wound up with toddlers who were developmentally advanced, scoring highly on language and cognitive tests. In an upcoming paper, she confirms the trend: 2-week-old babies whose mothers were under moderate stress show evidence of faster nerve transmission—and possibly more mature brain development—than those whose moms had stress-free pregnancies. It's hard to know what to make of the findings, but DiPietro has an intriguing theory. A stressed-out mother's "internal environment"—her heartbeat, blood pressure and other signals the fetus can perceive—is constantly in flux. Her restlessness may stimulate the fetus's brain, giving it something to think about. In this light, DiPietro thinks, the kind of mild to moderate stress that is pervasive in many women's hectic lives may be beneficial, perhaps even "essential," for fetal development. The idea is controversial—but if it's correct, it certainly complicates the theory that stress can permanently damage a child in utero.

When Stanford's Sapolsky gives lectures on stress, he cites the "depressing" research on failing neurons, some of which he has conducted. But his talks end optimistically, thanks to his observations in the wild. "If some baboons just happen to be good at seeing water holes as half full instead of half empty … we should be able to as well," he once told an audience. Even if we're not born well equipped to deal with stress, he said, "we can change," because as humans, we ought to be "wise enough to keep this stuff in perspective."

So how do we do that? One place to start is with the human equivalent of Zen baboons: Buddhist monks. Their mental stability and calmness isn't mystical; it's biological. The brain can grow new cells and reshape itself, and meditation appears to encourage this process. Monks who have trained for years in meditation have greater brain activity in regions linked to learning and happiness. "The mind is far more malleable than we previously assumed," says Saki Santorelli, executive director of the Center for Mindfulness in Medicine, Health Care, and Society at the University of Massachusetts Medical School. Studies at the center have shown that meditation can help people cope with stress. It may repair or compensate for damage already done to the brain.

Not all of us want to or can become monks; not all of us can spare even eight weeks for a course at the Center for Mindfulness. But there are quicker ways to learn to harness and handle stress. For this article, I tried one: the Williams LifeSkills program, a cognitive mini-makeover based on the research of Duke University psychiatrist Redford Williams. LifeSkills teaches adherents to approach life like a Zen baboon, picking the right battles—and it can be completed in a day and a half. "You won't achieve enlightenment, but it will help you," Williams told me before I embarked on the course, which gave me a formula for assessing conflicts (How important is this to me? Should I be mad? Can I do something about the problem? Would that be worth the trouble?). He was right. I did feel a bit calmer afterward. But then, I had willed myself to. I liked Williams; I was hoping his program would work.