Our preferences and dislikes for certain smells are largely universal, found a new study by researchers in Sweden and the UK. Although there is indeed some variation in the perception of smell among populations, culture does not seem to have any influence on the perception of smell. Instead, what we like or dislike is primarily determined by the chemistry of an odor. Vanilla and peaches were some of the most appreciated odors whereas, unsurprisingly, foot sweat ranked the worst smelling.
“We wanted to examine if people around the world have the same smell perception and like the same types of odor, or whether this is something that is culturally learned,” says Artin Arshamian, a researcher at the Department of Clinical Neuroscience at the Karolinska Institutet in Sweden. “Traditionally it has been seen as cultural, but we can show that culture has very little to do with it.”
“Cultures around the world rank different odors in a similar way no matter where they come from, but odor preferences have a personal – although not cultural – component,” added Dr. Arshamian.
Arsharmian's international team of researchers, which included colleagues from the University of Oxford and Stockholm University, ran experiments with 235 individuals who had to rank various odors on a scale of pleasant to unpleasant. The participants were selected from nine communities representing different lifestyles. Four of the communities were made of hunter-gatherer groups with little to no contact with Western foods and household articles. The other five communities employed different forms of farming and fishing and were well accustomed to the kind of smells readily encountered in industrialized societies.
As a result of these field experiments, the researchers found that there was quite a bit of variation between individuals within each group when assessing odors. About 41% of this variation was due to the molecular structure of the odor while the rest of the 54% was personal preference. The researchers found little indication of cultural transmission of preference for smells since members of the same group had personal preferences.
“Personal preference can be due to learning but could also be a result of our genetic makeup,” said Dr. Arshamian.
The most highly ranked smells across the board were vanilla and ethyl butyrate (the smell of peaches), while the least pleasant smells were those of cheese, soy milk, apple juice, but also foot sweat.
Despite individual preferences, most people seem to gravitate toward the same odors when it comes to the most enticing smells or, conversely, most foul odors. This makes sense since the olfactory sense is an essential survival sensor that can detect threats like poisoned food or nearby predators. It is simply evolutionary advantageous to sense these threats so most people have tuned their noses to detect them.
“Now we know that there’s universal odor perception that is driven by molecular structure and that explains why we like or dislike a certain smell,” Dr. Arshamian continues. “The next step is to study why this is so by linking this knowledge to what happens in the brain when we smell a particular odor.”
The findings appeared in the journal Current Biology.