Written by Anna Riordan
Some people claim love changes you, but does it change your brain? How and why does love change over time? What determines a successful, long-standing marriage? In a 2020 study titled, “After the Honeymoon: Neural and Genetic Correlates of Romantic Love in Newlywed Marriages,” researchers studied these questions. The researchers hypothesized that “romantic love is a developed form of the mammalian drive to find, and keep, preferred mates; and that its maintenance is orchestrated by the brain's reward system” (Acevedo et al., 2020).
Romantic love often declines over time, a phenomenon known as the “Honeymoon Period.” Researchers measured romantic love between couples during and after the honeymoon period by conducting functional MRIs (fMRI) and genetic testing around the time of their wedding (T1) and one year later (T2). Around their wedding, researchers tested nineteen first-time newlyweds by conducting an fMRI while showing them a picture of an acquaintance and then a picture of their partner. They collected saliva samples for genetic testing, and participants rated their relationship quality on the Eros romantic love scale. Researchers followed the same procedure a year later.
The researchers found for both measurements, successful, strong romantic relationships were associated with the activation of dopamine-, vasopressin-, and oxytocin-rich parts of the brain, and the interaction of dopamine, vasopressin, and oxytocin with genes related to pair-bonding, the formation of a relationship between a mating pair of adult animals. These chemicals in the brain are correlated with participants’ ability to form and sustain a long-term romantic partnership. Researchers also found polymorphisms, or variations, in genes associated with dopamine, vasopressin, and oxytocin function that affect the ability to sustain romantic love, suggesting that some people may be predisposed to falling in love based on their genes.
Based on the results, the researchers concluded that “romantic love maintenance is part of a broad mammalian strategy for reproduction and long-term attachment that is influenced by basic reward circuitry, complex cognitive processes, and genetic factors” (Acevedo et al., 2020). This provides more detail about the evolution and science of love and suggests that based on genetics, some people are better poised to maintain strong romantic love over time, so the fate of your relationship may be based on the luck of the draw.
Acevedo, B. P., Poulin, M. J., Collins, N. L., & Brown, L. L. (2020). After the Honeymoon: Neural and Genetic Correlates of Romantic Love in Newlywed Marriages. Frontiers in psychology, 11, 634. https://doi.org/10.3389/fpsyg.2020.00634