How spouses disagree may predict which ones are more likely to develop certain ailments down the road, new research suggests.
Analyzing 156 older couples over 20 years, scientists found that patterns of angry outbursts raised the risk of heart problems, while emotional withdrawal or "stonewalling" could lead to musculoskeletal issues such as back pain or stiff neck.
"We've known for a long time that stress and negative emotions are bad for your health," said study author Claudia Haase. She's an assistant professor of human development and social policy at Northwestern University in Evanston, Ill.
"But in our new study we wanted to dig deeper, and found that very specific behaviors led to specific health problems over time," she added.
Cardiovascular disease is the leading cause of death and a major cause of disability worldwide, according to the World Health Organization. Meanwhile, musculoskeletal symptoms such as back pain are among the most frequently reported health problems in industrialized nations, according to study documents.
Study participants were drawn from ongoing research of long-term heterosexual marriages, with about half of spouses aged 40 to 50 and the rest aged 60 to 70 at the start of the study. According to the 2009 U.S. Census, 96 percent of Americans over the age of 65 had been married at least once in their life.
Every five years, the couples were videotaped in a laboratory setting as they discussed areas of both enjoyment and disagreement. Expert behavioral coders rated the interactions based on facial expressions, body language and tone of voice. Spouses also completed questionnaires asking details about specific health problems.
To track displays of anger, the researchers combed videotaped conversations for behaviors such as pressed lips, knitted brows, raised or lowered voices and tight jaws.
To identify "stonewalling" behavior -- defined as shutting down emotionally during conflict -- researchers looked for so-called "away" behavior, such as facial stiffness, rigid neck muscles, and little or no eye contact.
The data was then correlated to health symptoms that were measured every five years over a 20-year span. The study didn't prove cause-and-effect between behavior and health problems, only an association. And, the links were strongest for husbands, though some of the key associations were found in wives as well.
The anger-cardiovascular relationship was most robust, with 81 percent of spouses rated in the "high anger" group experiencing at least one cardiovascular symptom within 20 years, Haase said. Cardiovascular symptoms include chest pain and high blood pressure.
Conversely, she said, about 53 percent of those in the "low anger" group had experienced such symptoms within the 20-year period.
About 45 percent of husbands rated as "high stonewallers" experienced back pain, muscle tension or stiff neck over the 20-year study. Only 23 percent of husbands who were "low stonewallers" had such symptoms in that time, Haase said.
"Our findings suggest that hot-headed people might want to consider if they would benefit from interventions such as anger management," Haase said. "If they're stonewalling, they may want to consider resisting the impulse to bottle up their emotions."
Vanessa Downing is a psychologist and behavioral health coordinator at the Christiana Care Center for Heart & Vascular Health in Wilmington, Del. She wasn't surprised by the study findings.
"When we look at health psychology as a whole and the movement to integrate psychologists into health care settings, it's because of the mounting research supporting these relationships between our emotions and personality traits and what happens with our health outcomes over time," Downing said.
But emotions such as disappointment or betrayal are normal in any long-term relationship, she noted, and it's only their chronic nature that can lead them to become destructive to one's health.
"Probably the most important message here is the importance of us starting to recognize our patterns," Downing said.
"A lot of times people get the message that they need to do something about their anger, for instance, because it's a problem for other people. But this study suggests that anger is really a problem for you, and that can be motivating for people because behavior change takes commitment," she explained.
The study was published online recently in the journal Emotion.