To determine whether or not someone is in a relationship, the most logical thing to do is to base ourselves, for example, on the information that we can collect visually, such as a person’s body language, among other signals. However, strange as it may sound, scientists seem to have discovered another telltale sign of being single: smell.
Specifically, scientists say that single men have a stronger odor than those with a partner, which would help them signal their availability to women, according to the results of an olfactory test carried out by researchers at Australia’s Macquarie University and published in the journal Frontiers in Psychology.
“Stronger body odor can help you stand out more. It could be a sign of dominance,” Mehmet Mahmut, one of the study’s authors, told Newsweek.
Higher testosterone levels in singles
In recent years, the science of human odor has given much to talk about. For example, previous research has shown that single men tend to have higher testosterone levels than those with a partner, due to the sexual competition associated with being single.
Still, scientists haven’t been able to conclude exactly why this difference is due, but they have a few theories: “Testosterone is associated with mate-seeking behaviors,” Mahmut says. “We know from previous research that higher testosterone is associated with stronger body odor…Potentially single men do have higher testosterone levels,” he added.
On the other hand, studies have revealed that heterosexual men also seem to be more attracted to a woman’s scent when their girlfriend is at the most fertile time of her menstrual cycle or when the woman is sexually aroused. Exposure to these pheromones can even cause men to drink more on a night out, reports Science Alert.
In addition to changes in scent, recent studies suggest that these hormonal changes might even directly alter a person’s appearance, though the results are still inconclusive.
The study
To arrive at their results, the researchers provided 91 men with a plain white T-shirt and instructed each participant to wear it for one day. The 46 singles and 45 coupled men were also advised to get moderate exercise to ensure that “a significant amount of sweat was absorbed in the underarm of the T-shirt.”
After collecting the T-shirts, the researchers asked 82 heterosexual women between the ages of 18 and 35 to rate body odors — armpit snips from each T-shirt, which were stored in a bottle — and the faces of heterosexual men. Half of the women were single, while the other half had a partner.
After studying the results, in which the testosterone levels of the participants were not directly analyzed, the scientists discovered that single men had stronger body odor than those with a partner. The more pleasant the male scent was, the more likely women were to rate his appearance as favourable.
“We also found that the faces of single men were considered more masculine than those of partnered men, but only among partnered women,” the study authors wrote.
“From an evolutionary perspective, it may be advantageous for females to be able to detect the chemical signals that connote mating and ultimately avoid courting mated males (especially with offspring) due to the relatively few resources they can offer.”
More studies are still needed
Although the authors state that their results are “consistent with previous research showing that single and partnered men can be differentiated based on their testosterone levels,” they also noted that correlation is not necessarily indicative of causation and that the data they may have been biased by certain demographic factors.
“Older men are more likely to have a partner, and testosterone declines as you age,” said Mahmut, who speculated that there might be other reasons for this discrepancy in body odor as well.
“It could be a business reason,” he said. “It’s possible that having a partner say ‘hey, you haven’t showered in a day’ makes you more likely to have less body odor,” she added.
Mahmut hopes that his research will help us better understand the science of human attraction. In particular, his relationship with the sense of smell, which has been, in many cases, ignored by science and which could have a close relationship with our sexual behavior.
“Being attracted to a partner … is the foundation of life,” he told Newsweek. “A basic part of being human is forming connections with other people. A life partner is one of the most important connections you will ever make.”
