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People in harmonious relationships may start thinking in synch, according to new research. Hinterhaus Productions/Getty Images
  • Although research suggests several factors may contribute to a harmonious relationship, what predicts marital satisfaction is not fully understood.
  • Research also indicates that long-term couples often begin to think and behave similarly, leaving many unanswered questions about how this might play a role in marital satisfaction.
  • A recent study from Stanford University in collaboration with researchers in China has uncovered evidence that shared brain activity may predict marital happiness.
  • Their findings also provide insights into the neurobiological foundation of human marital bonding.

Marital satisfaction and romantic compatibility have been the subject of research for decades. Yet, scientists are only beginning to understand why some couples report happiness within a relationship and others do not experience this type of relationship satisfaction.

So far, research has identified several factors that may contribute to an individual’s happiness in their relationship. For example, a 2016 systematic review of research found that religion, sex, and communication impacted marital satisfaction. Interpersonal factors and mental health also played a role, along with occupation, length of the marriage, age, and the number of children a couple had.

In addition, over time, harmonious couples often begin to think and behave in similar ways. For instance, a 2021 study found evidence of personality synchrony over time within older adult couples.

Still, scientists have yet to fully understand if this synchronicity between romantic partners indicates greater relationship satisfaction.

However, a new study from Stanford University researchers in collaboration with scientists in China has uncovered more insight into marital satisfaction.

Specifically, they found that heterosexual married partners who reported higher marital satisfaction also had synchronized brain activity when viewing marriage-related images.

Moreover, in contrast to other research, the scientists found no significant association between marital satisfaction and age, sex, personality traits, or marriage length.

The research appears in the Proceedings of the National Academy of Sciences (PNAS).

The study authors hypothesized that measuring marital satisfaction might be possible by looking at the brain’s response to marital and socially relevant cues.

They also proposed that since growing evidence indicates neural activity in partnered individuals becomes increasingly synchronized over time and shared life experiences, these synchronicities might contribute to greater marital satisfaction.

To investigate this theory further, the scientists recruited 35 heterosexual couples in China who had been married for at least a year. The researchers also included randomly selected male-female pairs that were not married.

First, the research team determined whether behavioral or personality factors predicted marital happiness by having study participants complete several questionnaires on marital satisfaction and adult attachment. The participants also completed the Big Five Personality Inventory.

Then, the participants underwent fMRI scans of the brain while viewing relationship-related and object-related movie clips. The scientists hoped to identify whether married couples showed more brain activity synchronization than randomly selected male-female pairs.

The scientists analyzed the data by computing intersubject synchronization (ISS) between married couples. The team also used dimensional and categorical analyses to determine whether the ISS between married couples was associated with marital satisfaction.

In addition, the researchers also examined what role the default mode network (DMN) — a brain network linked to thoughts, emotions, or beliefs about oneself and others — played in marital happiness.

Specifically, the team looked at whether ISS in the DMN was related to specific factors of marital satisfaction, including personality, communication, and conflict resolution.

The analysis showed that married couples who reported greater marital satisfaction were more likely to show activity in similar parts of the brain when they watched the relationship-related movie clips. However, this synchronized neural activity did not happen when they viewed object-related images, regardless of reported marital satisfaction.

Moreover, happily married couples showed more synchronized brain activity than randomly paired couples.

In a Stanford Medicine article, study author Dr. Vinod Menon, a professor of psychiatry and behavioral sciences at Stanford University, said, “we found that the links between marital happiness and behavioral measures, like personality tests, were quite weak.”

In the article, Dr. Vinod explained that “married couples overall, compared with random couples, had more similar brain activity independent of levels of satisfaction. On top of that, you get additional synchronization in those who self-report to be more satisfied in their marriage.”

Individuals come together and create pair bonds due to many complex factors. But when and how a couple develops synchronized thinking is not fully understood.

“We don’t know whether there [are] selection-based behaviors arising from similar brain activity in a relationship, or whether couples evolve over time to develop similar anticipatory and predictive brain representations,” Dr. Menon explained in the Stanford Medicine interview.

Dr. Jared Heathman, board certified psychiatrist with Your Family Psychiatrist in Houston, Texas, told Medical News Today:

“Married couples often think the same, which is called synchronized thinking. This type of thinking can be something that brings couples together. People often choose partners that are similar to them. Synchronized thinking can [also] be a learned response that occurs after a couple has been together for a long period of time.”

Interpreting the study results, Dr. Heathman added, “my thoughts on this are that in a relationship, both partners move toward a similar line of thinking regarding needs, wants, and hopes. Both partners influence each other.”

“Although both partners are in sync about marriage, they may have different views and perspectives on some various topics, thus explaining why they did not have similar brain activity when viewing non-relationship related images,” he added.

Dr. Monica Vermani, clinical psychologist and author of A Deeper Wellness: Conquering Stress, Mood, Anxiety and Traumas, told MNT:

“Couples with similar thinking styles and personalities often come together easily, cohabit well, and easily live in harmony. On the other hand, some people come together because, […] they lack certain traits in themselves, and seek out partners who possess the traits they lack in order to attain a sense of balance.”

“In successful partnerships where these dynamics are in play, both individuals respect, admire, and learn from one another. Over time being together, they are often challenged and inspired to learn from and acquire the traits they admire in their partner.”
— Dr. Monica Vermani

Regarding the study’s results, Dr. Vermani suggests that “brain similarities confirm shared perceptions, thought patterns, ways of processing emotion, anger, interpersonal and social interactions, and even analytical versus emotional reasoning.”

“Such neurological/brain activity commonalities can be strong predictors of marital satisfaction,” she concludes.