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Recent research published in PNAS suggests that having difficult people in your close social circle is associated with measurable increases in biological aging. Scientists found that individuals who report having “hasslers” in their lives tend to experience a faster pace of cellular aging and an elevated risk for various health problems. These findings provide evidence that promoting healthy aging requires reducing chronic interpersonal stress, not just strengthening supportive relationships.
“What drives this study is a simple observation: most of what we know about social relationships and health has focused on the protective power of friends and family who buffer stress and promote well-being. But nearly 30% of adults report someone in their inner circle who regularly makes life harder. We wanted to know whether that kind of chronic interpersonal stress leaves a biological trace,” said study author Byungkyu Lee, an assistant professor of sociology at New York University.
To answer this question, the scientists analyzed data from the Person-to-Person Health Interview Study. This project included a representative sample of 2,345 adults living in Indiana. Participants completed detailed surveys about their social networks, identifying the people they interacted with regularly.
During the interviews, participants specifically named individuals who often caused them problems or made their lives difficult. The researchers defined these difficult people as hasslers. They also asked participants about the nature of these relationships, such as whether the difficult person was a family member, a spouse, or a friend.
To measure biological aging, the researchers collected saliva samples from the participants. They analyzed the saliva using advanced laboratory tools known as epigenetic clocks. These tools look at DNA methylation, which is a natural chemical process that changes how genes are turned on or off without altering the underlying genetic code.
By tracking these chemical tags, scientists can estimate a person’s biological age, which reflects how old their cells act rather than their chronological age in years. The researchers used two specific tools to calculate both the accumulated cellular damage and the current speed of physical decline. They then compared these biological markers to the number of stressful people each participant reported.
The scientists found that negative social ties are relatively common, with nearly 30 percent of participants reporting at least one hassler. The data indicates that exposure to these difficult people is not random. Women, daily smokers, people in poorer health, and those who experienced childhood trauma were all more likely to report having stressful individuals in their networks.
“It was striking that negative ties were linked to molecular measures of aging, not just self-reported stress or mental health,” Lee told PsyPost. “Each additional hassler in a person’s close network was associated with the body being biologically older than it should and aging at a faster pace.”
“It is about 9 extra months on the odometer and a 1.5% faster speedometer reading. Although the effect of each hassler might seem small, biological aging is cumulative, so even modest differences in pace can add up over years. To put this in perspective, the hassler association corresponds to roughly 13% to 17% of the estimated effect of smoking on these same aging measures. That is not trivial.”
The researchers also found evidence that the relationship type matters. Family members who act as hasslers showed the strongest association with accelerated aging. “That suggests the ‘stickiness’ or inescapability of certain roles may be especially important,” Lee said.
In other words, because family ties are often embedded in obligations and shared spaces, they are difficult to escape. This inescapable nature might trap individuals in repeated stressful interactions. In contrast, spouses who caused difficulties did not show the same strong association with accelerated aging, possibly because marriage mixes negative exchanges with positive support.
Beyond biological aging, the scientists discovered that negative social ties are linked to a broad range of other health issues. Participants with more hasslers tended to have higher levels of systemic inflammation. They also exhibited higher rates of depression, greater anxiety severity, and a higher body mass index.
These results suggest that chronic social stress places a heavy burden on the body’s physiological systems. Repeated interpersonal tension likely activates stress response systems, releasing hormones that eventually cause wear and tear on organs and tissues. This chronic activation provides a clear pathway linking bad relationships to poor physical and mental health.
“These findings suggest that promoting healthy aging requires not only strengthening supportive ties, but also reducing chronic interpersonal stress within close relationships,” Lee explained.
While the study provides robust data, there are potential misinterpretations to avoid. Because the research is observational, it cannot prove that hasslers directly cause accelerated aging. There are alternative explanations, such as the possibility that people who are biologically aging faster become more irritable and provoke negative interactions.
“A key caveat is that this study is observational, so we can’t claim that hasslers cause accelerated aging from these data alone,” Lee told PsyPost. “The associations are consistent with hasslers functioning as chronic stressors that drive biological wear and tear, but alternative explanations exist, including reverse causation (people aging faster may elicit more negative interactions), perceptual bias (people with more negative affect may perceive benign exchanges as hassling), and confounding from observed and unobserved factors.”
“We took multiple steps to address these concerns: adjusting for prior comorbidity using linked electronic health records, examining whether hasslers predicted health in a follow-up survey after controlling for baseline health, incorporating occupational and psychosocial covariates, adjusting for respondents’ affective orientation toward others, and conducting sensitivity analyses for unobserved confounding. These checks increase confidence in robustness but do not constitute causal estimates.”
For future research, the scientists plan to conduct longitudinal studies to track how changes in difficult relationships predict shifts in aging over time. Following the same individuals for years will help clarify the exact direction of the effect. They also hope to map the specific genetic markers that are altered by chronic interpersonal strain.
“We want to dig deeper into mechanisms by conducting an epigenome-wide association study (EWAS) of ‘hassler’ exposure to identify specific DNA methylation patterns linked to chronic interpersonal strain,” Lee said.
“One broader message is that ‘social health’ isn’t only about having people around. It is also about whether those close ties are a source of support or a source of chronic strain. Public conversations about healthy aging often focus on individual behaviors like diet and exercise, but our findings underscore that the social environment, especially the difficult relationships people can’t easily escape, may also be part of the aging equation.”
The study, “Negative social ties as emerging risk factors for accelerated aging, inflammation, and multimorbidity,” was authored by Byungkyu Lee, Gabriele Ciciurkaite, Siyun Peng, Colter Mitchell, and Brea L. Perry.
