A recent study in Personality and Social Psychology Bulletin examined how married couples in both the United States and Japan influence each other’s well-being over time. The researchers found that spouses’ levels of well-being are positively associated with one another, with both American and Japanese couples displaying what the authors call “spousal interdependencies.” These interdependencies appear to be shaped by two key factors: the mutual influence between partners and the shared environments they inhabit.
Previous research has shown that well-being in couples is often interdependent. For example, a study conducted by Ulrich Orth and his colleagues found that that spouses’ happiness, life satisfaction, and emotional states influence each other significantly over time, with this interdependence driven by mutual influence and shared environmental factors.
Mutual influence reflects how one partner’s well-being directly affects the other’s over time. For instance, a positive change in one spouse’s happiness can lead to a similar boost in the other spouse’s mood. Shared environmental factors, on the other hand, include the life circumstances both partners experience together—such as financial situations, household responsibilities, or shared social circles—which shape their well-being similarly and in parallel ways.
The authors of the new study, led by Ryosuke Asano, wanted to broaden the existing research to include Japanese couples, exploring whether cultural differences might shape how couples affect each other’s happiness and life satisfaction. By doing so, they aimed to not only replicate findings from past studies but also to determine if these patterns held up across a different societal and cultural context.
“I have been interested in close relationships and well-being throughout my career,” said Asano, an associate professor at Kurume University. “When I read Orth et al.’s paper (2018, Developmental Psychology), I thought that it would be worthwhile to elaborate it in more depth. In particular, I wanted to generalize their theories to the Japanese population.”
To conduct their study, the researchers gathered a large sample of American and Japanese couples. The American sample consisted of 3,012 couples aged 26 to 96, while the Japanese sample included 2,307 couples between the ages of 24 and 76. The study involved a combination of cross-sectional and longitudinal surveys, meaning they collected data from participants at several points over time to observe how well-being shifted within each relationship.
Both the American and Japanese participants completed measures assessing various aspects of well-being, such as life satisfaction, positive and negative emotions, and symptoms of depression. These metrics allowed the researchers to capture a comprehensive view of well-being across a wide age range and to explore how partners’ experiences might impact each other.
To analyze the data, the researchers used a statistical method that allowed them to separate mutual influence and shared environmental factors. Using models that traced these influences over time, the researchers could see how couples’ well-being aligned and what might explain those patterns.
The study confirmed that well-being among married couples is interconnected, both in the United States and Japan, suggesting that spousal well-being is inherently interdependent across different cultural contexts. For both American and Japanese couples, when one spouse reported higher levels of life satisfaction or positive emotional states, the other spouse tended to reflect similar levels over time.
This pattern supports the idea that marriage forms an environment where partners’ happiness and emotional well-being become intertwined, regardless of cultural differences. The study’s findings demonstrate that this interdependence operates through two main mechanisms: mutual influence and shared environmental factors.
“We found that the interdependent nature of well-being is common for American and Japanese spouses,” Asano told PsyPost. “In particular, estimates for spousal interdependencies in well-being and two different sources of these interdependencies (i.e., mutual influence and shared environmental influences) are of very similar magnitude for Americans and Japanese.”
While this study sheds valuable light on the ways that married couples’ well-being is interconnected, it also has some limitations. For one, although the American sample was representative of the national population, the Japanese sample was drawn from a convenience sample, which might limit the generalizability of these findings. Additionally, self-reported well-being measures may be subject to biases, such as current mood or a desire to present oneself positively. Future research could benefit from including more diverse samples from other cultures and using different methods, such as partner observations, to measure well-being more objectively.
“My long-term goal for this study is to understand how close relationships affect well-being,” Asano said. “To this end, we seek to collect longitudinal couple data with a nationally representative design in Japan, as in North America and European countries.”
The study, “The Interdependent Nature of Well-Being: Evidence From American and Japanese Spouses,” was authored by Ryosuke Asano, Yuji Kanemasa, Kentaro Komura, and Kenichi Ito.