According to research from the University of Bonn (Germany), men involved in a stable relationship feel more satisfied with their partners after having inhaled a dose of oxytocin, the “love hormone”. This reaction would be linked to the reward systems of the brain, which trigger a feeling of gratification when faced with certain stimuli and which also intervene in drug addiction.
Oxytocin is a hormone linked to sexual and parenting patterns, as it is released both during intercourse and during pregnancy. Due to this nexus, scientists have investigated its involvement in sexual monogamy, a behavior that underlies human nature and is very rare in other mammals due to its high evolutionary cost.
The team asked 20 single men in a multi-year relationship about the attractiveness of various women in their family, their environment and strangers. When men saw images of their girlfriends after having inhaled oxytocin, they rated them above the rest . The MRI scan showed that after the dose, the areas of the brain associated with the reward were activated to a greater degree when viewing photographs of their partners. Oxytocin even increased the neural response towards a partner compared to a known woman, indicating that this reaction is specific to partner bonds, not familiarity.
The finding assumes that the increase in oxytocin levels experienced by men during infatuation increases the psychological reward derived from spending time with their partner, thus reinforcing their monogamous behavior.
