Is Marriage Good for Your Health?

Initial research was an overwhelming yes... but our understanding is getting a bit more nuanced:

But while it’s clear that marriage is profoundly connected to health and well-being, new research is increasingly presenting a more nuanced view of the so-called marriage advantage. Several new studies, for instance, show that the marriage advantage doesn’t extend to those in troubled relationships, which can leave a person far less healthy than if he or she had never married at all. One recent study suggests that a stressful marriage can be as bad for the heart as a regular smoking habit. And despite years of research suggesting that single people have poorer health than those who marry, a major study released last year concluded that single people who have never married have better health than those who married and then divorced.
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Kiecolt-Glaser told me that the overall health lesson to take away from the new wave of marriage-and-health literature is that couples should first work to repair a troubled relationship and learn to fight without hostility and derision. But if staying married means living amid constant acrimony, from the point of view of your health, “you’re better off out of it,” she says.

There is even a biological reason why, if your partner is under some stress, that a simple holding of the hand, or a hug can do wonders:

Researchers have also started to examine the salutary health effects of social relationships, including those of a good marriage. In one recent study, James A. Coan, an assistant professor of psychology and a neuroscientist at the University of Virginia, recruited 16 women who scored relatively high on a questionnaire assessing marital happiness. He placed each woman in three different situations while monitoring her brain with an f.M.R.I. machine, which offers a way to observe the brain’s response to almost any kind of emotional stimulation. In one situation, to simulate stress, he subjected the woman to a mild electric shock. In a second, the shock was administered, but the woman held the hand of a stranger; in a third, the hand of her husband.

Both instances of hand-holding reduced the neural activity in areas of the woman’s brain associated with stress. But when the woman was holding her husband’s hand, the effect was even greater, and it was particularly pronounced in women who had the highest marital-happiness scores. Holding a husband’s hand during the electric shock resulted in a calming of the brain regions associated with pain similar to the effect brought about by use of a pain-relieving drug.

Coan says the study simulates how a supportive marriage and partnership gives the brain the opportunity to outsource some of its most difficult neural work. “When someone holds your hand in a study or just shows that they are there for you by giving you a back rub, when you’re in their presence, that becomes a cue that you don’t have to regulate your negative emotion,” he told me. “The other person is essentially regulating your negative emotion but without your prefrontal cortex. It’s much less wear and tear on us if we have someone there to help regulate us.”

There are a lot more interesting experiments in that article.