Couples tend to experience similar ups and downs in the stress hormone cortisol — a phenomenon known as cortisol synchrony. According to new research published in the journal Psychoneuroendocrinology, older couples living in more conservative German states tend to exhibit more pronounced cortisol synchrony than couples living in more leftist states.
The findings provide evidence that interpersonal physiological dynamics are related to one’s socio-political environment.
“There is really not much research on how daily life health-relevant interpersonal dynamics are shaped by larger socio-contextual features,” said study author Theresa Pauly, a postdoctoral fellow at the University of Zurich.
“We know that romantic partners influence each other’s health, for the good and bad. In this study, I was interested in examining one physiological pathway that could partly be responsible for health being more alike in couples: an interdependence in their stress hormone levels (cortisol).”
The study examined couples aged 56–89 years who were part of the German Socio-Economic Panel, a nationally-representative longitudinal study that began in 1984.
“To observe whether and how romantic partners show synchronized ups and downs of cortisol in their daily lives, we asked 160 older couples to provide multiple saliva samples each day for a 7-day period,” Pauly said. “These saliva samples were then assayed for cortisol levels.”
“The couples resided in different geographical locations across Germany (13 different federal states); this made it possible to examine whether everyday cortisol synchrony in older couples would be different, depending on the socio-political context.”
To determine the socio-political leanings of each federal state, the researchers analyzed data from the Manifesto Project Database and voting results from the 2017 German federal election.
Pauly and her colleagues found that the couples tended to have similar fluctuations in day-to-day cortisol levels, which was linked to their socio-political environment.
“Older couples showed synchronized ups and downs in their cortisol levels in their daily lives. This means that if one person had higher cortisol than usual, the other one tended to have elevated cortisol, too. And if one person had lower cortisol than usual, the other one tended to have a lower cortisol level as well,” Pauly explained to PsyPost
“We also made sure that the synchrony does not result from any common behavioral patterns (e.g., eating times) – because cortisol is also influenced by a number of daily life factors besides stress such as exercise, eating, and drinking coffee or alcohol.”
“When examining whether cortisol synchrony differs by the political context, we found that couples living in more right-oriented (conservative) contexts showed higher cortisol synchrony, as compared with those living in a more left-oriented political context,” Pauly noted. “This suggests that there is an association between political context and the interdependence in couples’ cortisol levels, i.e. how much one partner’s cortisol changes in unison with the other partner’s cortisol in their daily lives.”
But there is still much to learn about the causes and consequences of cortisol synchrony.
“We do not really know whether a high interconnection in one’s stress hormone levels is good or bad. Research demonstrates that it might depend on the context,” Pauly said.
“On the one hand, there is research linking higher cortisol synchrony (especially when it happens during conflict) to worse relationship outcomes, particularly in younger samples. However, in another study we have also linked greater cortisol synchrony to positive partner interactions in older couples such as feeling understood and appreciated and seeking help or closeness to the partner. There is some literature suggesting that synchrony might be important for perspective-taking and empathy.”
“Furthermore, we do not really know why a more right-oriented context would go along with greater couple synchrony,” Pauly continued. “In Germany, the major parties located on the political right lean towards a prioritization of family issues and emphasize family values. We speculate that this might result in a greater focus on the couple relationship (as compared to other relationships, e.g. with friends), and thus greater interdependence between partners.”
The study, “Political context is associated with everyday cortisol synchrony in older couples“, was authored by Theresa Pauly, Karolina Kolodziejczak, Johanna Drewelies, Denis Gerstorf, Nilam Ram, and Christiane A. Hoppmann.