New research published in the journal Scientific Reports reveals the influence of scent in women's friendship choices, suggesting that olfactory cues play a role in how women decide whom they like and want to befriend.
In a collaborative study reported by the New York Post, researchers from Cornell University, Middle Tennessee State University, and Sabancı University in Turkey conducted a speed-friending experiment with 40 female participants aged 18 to 30 to explore how everyday scents affect friendship formation. The participants were each photographed and given a simple cotton T-shirt to wear for about 12 hours during their normal daily activities. They were instructed to maintain their usual hygiene routines, including the use of deodorant and perfume, to capture their "diplomatic odor"—a mix of their natural scent and the products they use.
Before meeting in person, the participants viewed 100-millisecond flashes of photographs of other participants and rated their "friendship potential" based on several criteria. Additionally, they smelled and rated the T-shirts worn by the people they were about to meet, assessing whether they would like to be friends, date, or avoid them in the future.
On the day of the speed-friending event, the women engaged in 10 rounds of four-minute face-to-face conversations, chatting with fellow participants. After each interaction, they provided friendship ratings. Following these live interactions, they smelled and rated the same shirts again.
The study found a strong correlation between the initial scent-based friendship ratings and the assessments made after in-person meetings. "The consistency of the judgments across the three rating opportunities is remarkable," said Vivian Zayas, a psychology professor involved in the research, according to La Tercera. She added, "It's amazing, our attunement to other people, even without being consciously aware of how in tune we are."
"It's not just about perfume. It's your food choices. Do you like cats or dogs? What detergent do you use? All these choices combine to create what we call 'diplomatic odor.' You live in this olfactory space; does it match with the people you interact with?" said Jessica Gaby, assistant professor of psychology at Middle Tennessee State University and first author of the study.
The researchers observed that participants' evaluations of the T-shirts changed based on their personal interactions. If they enjoyed talking with someone during the brief meeting, their rating of that person's scent became more positive afterward. "What surprised me the most was the learning, the change in the second series of readings: a single interaction and you think, 'Hmm, maybe not.' A single in-person interaction with a person can change the way you perceive their body odor. This seems amazing to me," said Gaby.
The findings suggest that our brains actively update scent associations based on social experiences, and as relationships develop, this process may continue, potentially strengthening emotional bonds. The researchers attributed this to the fact that someone's "diplomatic odor" provides subtle, personal preferences that help our brains decide whether we're likely to get along with someone.
The article was written with the assistance of a news analysis system.