Scientists have long believed that scent plays a role in attraction, but a new study suggests its influence extends to friendships too. Researchers found that when two women meet for the first time, their sense of smell helps them decide if they’ll be friends. This is achieved by analyzing “diplomatic odor,” which takes into account everyday scents from food, laundry, and environment.
According to evolutionary psychology, humans have a preference for sexual partners with different major histocompatibility complex (MHC) genes, which are linked to immune system function. A 1995 study showed that women preferred the scent of men with dissimilar MHCs. However, this finding reversed when oral birth control was taken.
Building on this research, scientists conducted a study where they analyzed scents from T-shirts worn by men for two days. The results revealed that women preferred the scent of men with dissimilar MHCs to their own. This preference varied among participants, particularly those taking oral birth control.
The latest paper focused on “diplomatic odor” – a combination of everyday scents that influences social interactions. Co-author Jessica Gaby stated, “It’s not just perfume; it’s your dietary choices and lifestyle habits.” These scent profiles help determine compatibility with others, suggesting that our daily odors can reveal our personality traits and living spaces.
The study suggests that even though we may be able to look beyond physical appearance in friendships, our sense of smell still plays a crucial role.
Source: https://arstechnica.com/science/2025/04/smells-like-teen-friendship-how-scent-influences-social-choices