New research provides evidence that biological mechanisms play an important role in the maintenance of romantic love in marriages. The study of newlywed couples, published in Frontiers in Psychology, indicates that genetic influences and the brain’s reward system are both associated with sustaining romantic love.
“I realized the importance of relationships at an early age, and it was and continues to be what captivates my attention. Relationships make the world go around. They add meaning, color and joy to our lives, or in some cases when people are attached they can create a lot of suffering,” said study author Bianca Acevedo, a research associate at the University of California, Santa Barbara
“They are also good for our health. Meaningful connection is one of the most powerful and simple tools we have to improve our lives and the lives of others. I am intrinsically curious about the nature of relationships and committed to using science to help us better understand relationship dynamics.”
The researchers used functional magnetic resonance imaging (fMRI) to examine brain activity in 19 healthy, right-handed women and men as they viewed alternating images of their partners and a neutral acquaintance they knew well. The participants also completed a battery of questionnaires that assessed romantic love, sexual satisfaction, and other factors.
The participants were tested around the time of their marriage and again a year later. They also provided saliva samples, which the researchers used to test for genes implicated in pair bonding in non-human mammals, such as voles.
Acevedo and her colleagues found that romantic love maintenance was associated with heightened brain activity in the dopamine-rich substantia nigra and several other cortical areas in response to seeing a partner’s face. They also found evidence that dopamine-related genes were associated with sustaining romantic love over time.
“Love activates the reward system of the brain which is important for motivation and working for what we want. It is a survival system that motivates us to go out and get what we want and need, like water, food and a romantic partner,” Acevedo told PsyPost.
“However, it’s complicated. We also see activation in response to a beloved in areas of the brain that are important for attachment, memory, and physiological homeostasis, as well as cortical activity related to decision-making and cognitive processing. In sum, love is complicated. It is one of the most basic things that we do as a species but it’s also complex.”
Romantic love was also linked to relationship satisfaction and frequency of sexual activity. The researchers found heightened brain activity in the paracentral lobule, a genital sensorimotor region, in participants who maintained love for their partner over the one-year time period.
“Although many therapists have suggested an important role for sexual activity in maintaining a marital relationship, this is the first time a cortical brain region associated with direct sexual stimulation has been correlated with self-reports of romantic love in marriages while simply thinking (and viewing face images) of a spouse,” the researchers said.
“Humans are wired for love. However, it’s important to take note that love can take many different forms. Some individuals have a biological predisposition for forming and maintaining pair-bonds. Also, we are learning that some individuals may also have a genetic predisposition for staying in love,” Acevedo said.
“However, humans have the capacity to override their impulses through engaging higher order thinking and self-regulation. Love is basic but complex, and it takes work to keep love alive.”
The new study — like all research — also includes some limitations.
“Most of our research has been based on people that are in-love, and in some cases also happily married. Also, our samples are often constrained by the parameters of the scanner. Therefore, most of our study participants have been relatively healthy and people that were willing to come forth and help us better understand the biological basis of love. They had the time and were relatively conscientious about science,” Acevedo explained.
“Also, to the point made by Goetz et al. (2019), regarding the non-representative status of participants and being WEIRD (Western, Educated, Industrialized, Rich, and Democratic), it is important for future studies to make concerted efforts to recruit more representative samples.”
The study, “After the Honeymoon: Neural and Genetic Correlates of Romantic Love in Newlywed Marriages“, was authored by Bianca P. Acevedo, Michael J. Poulin, Nancy L. Collins and Lucy L. Brown