Why Long-Term Partners Feel Each Other’s Pain, According to Science

Studies indicate that long-term intimate relationships can actually influence physical and mental health over time.

Several years ago, not long after we welcomed a puppy into the family, my shoulder became stiff and sore. It quickly morphed into “frozen shoulder,” a condition that commonly strikes women in their 40s and can be triggered by repetitive strain. I assumed it was from the dog constantly pulling on her leash like an out-of-control yo-yo.

My husband of nearly two decades was, of course, sympathetic about the searing pain that shot down my arm like a lightning bolt whenever I reached for something slightly out of range. But then, a few months later, a weird thing happened: Just as my shoulder was loosening up and the sharp pain was receding to a dull ache, my husband developed a frozen shoulder in his left arm, too. It wasn’t from the dog—I did most of the walking and by the time his pain appeared, the puppy was all trained up.

I would have chalked it up to coincidence, but when I started experiencing tendonitis in my right elbow last year—likely a result of too many hours spent clacking on my laptop—hubby began complaining about pain in his elbow at the same time, and he rarely sits at a desk all day long. What were the chances? And also, how annoying! Instead of being nursed through my ailment I was once again mustering sympathy for his copycat symptoms.

A quick Google search turned up a story about how long-term couples have a tendency to become in sync, health-wise, over time. “People have been aware of this phenomenon for the last half century—that we’re connected—but now we have the methodology to begin to model these dynamics in new ways,” says Shannon Mejia, an assistant professor in the department of kinesiology and community health at the University of Illinois Urbana-Champaign. “As we’re studying how people’s lives unfold, we recognize that they’re unfolding with others’.”

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Mejia calls her area of research “lifespan psychology.” It looks at the way individuals shape their own development, and how shared environments, shared behaviors, shared beliefs about aging, and partner selection all intersect to influence health as couples age together.

Her research has shown that couples who share optimism about aging are healthier overall. They share fewer constraints on daily activities, such as climbing a flight of stairs or picking up a coin, as they get older. What’s more, partners who have weathered decades together have similar cholesterol levels, kidney function and grip strength, which is an important indicator of muscle endurance and overall health. Other studies have linked these shared health behaviours—termed “spousal concordance”—with diabetes, cardiovascular disease and depression, making a strong argument that long-term intimate relationships can influence physical and mental health trajectories over time.

To explain how my husband and I both became stricken with a frozen shoulder within months of each other, Mejia posits that shared behaviours over the years might have led to similarities in posture and vulnerability, which could have resulted in the same shoulder injury. Called “postural synchrony” in psychology circles, ours is a more extreme case of two people whose feet fall into step while walking or who lean into one another like mirror images to show interest on a date.

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Playing into it, too, is the notion of “pain empathy”—the fact that seeing someone in pain creates, at the very least, psychological pain in the observer. Watching another person suffer, particularly a loved one, “evokes a strong psycho-social reaction,” says Kenneth Craig, director of the B.C. Pain Research Network and professor emeritus of psychology at the University of British Columbia. “There’s going to be some correlation between the reaction of the observer and the person who’s actually in pain.”

An instance of this phenomenon is a sympathetic pregnancy, where non-pregnant people find themselves experiencing much the same symptoms as their partners. “Extreme reactions can go beyond pain to include weight gain, fatigue, difficulty walking,” Craig says. But he points out that it can also include pain that mirrors their partner’s distress during contractions.

These examples all tie into the idea that shared experiences, beliefs, behaviours and environments lead to similarities in health, for better or worse, and that’s really the crux of Mejia’s research.

She’s found that up to 20 percent of the differences in health that married adults experience are due to the relationship rather than the individual. So why not harness the power of two for good? Couples can inspire each other to stick with healthy habits like exercising, eating well and going to bed at a reasonable hour.

After nearly 25 years of marriage—and two healed shoulders—I like to think that my husband and I share a lifestyle that’s conducive to healthy aging (our adorable pulling dog aside).

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So do Liz and Remy Tompkins, both 55, a couple from Calgary married 31 years. They recently sold their home and just about all of their possessions and are currently driving across North America in a retrofitted van, taking the time to stretch, exercise and meditate daily. Though they each have their own individual aches and pains, they’re eerily sympatico when it comes to a low resting heart rate and healthy blood pressure. They chalk it up to genetics and an active lifestyle, but it also looks a lot like spousal concordance.

The Tompkins share the dream of a future where they’re healthy and active. They’ve gone so far as to set intentions around these healthy behaviours, and a big motivator has been watching their own parents age.
“I don’t want to end up in the same sort of condition as I see [my parents] in their 80s,” says Remy, whose dad has had a couple of strokes and whose mom is diabetic. “I want to preserve my abilities.”

Liz is also of the “use it or lose it” mentality and shares her husband’s positive vision about aging. “We’re going to have a very active old age because we share an active, healthy lifestyle,” she says.

Talking about health in this way and figuring out how to support each other through aging are steps in the right direction for couples who don’t want to be limited as they grow old, says Mejia.

“I would advocate for formalizing this shared environment. ‘Who are we? How do we think about our health? How do we want to support our health?’” she says. “Really recognize that you’re in this together.”

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Originally Published in Best Health Canada