SOLNA, Sweden — Although people around the world don’t always see eye to eye, a new study finds we all have one thing in common: we like the same smells. An international team of researchers found that it’s human nature to enjoy the smell of vanilla and peaches and there may even be an evolutionary reason behind it.
“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, Karolinska Institutet in a university release. “Traditionally it has been seen as cultural, but we can show that culture has very little to do with it.”
People tend to enjoy certain pleasant smells regardless of where they come from or their cultural affiliation. While the team did not directly study it, the findings suggest having a universal odor perception likely increased the chances of our ancestor’s survival. Rather than a learned cultural experience, people considered a smell pleasant based on the structure of the odor molecule.
“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,” explains Dr. Arshamian.
The researchers studied the odor preferences of 235 individuals from nine indigenous populations. Four were hunter-gatherer groups and five groups were from farming and fishing villages. These groups have little exposure to Western culture and foods.
“Since these groups live in such disparate odiferous environments, like rainforest, coast, mountain and city, we capture many different types of ‘odor experiences’,” says Dr. Arshamian.
So, which smell reigns supreme?
The team asked people to rank a variety of smells from pleasant to unpleasant. While there was a small amount of individual variation in the results, most people were consistent in what they considered soothing or stinky. Further analysis showed about 41 percent of the variation in the response was from the molecular structure of the odor and 54 percent comes down to personal preference. Dr. Arshamian suggests personal preference may have come from cultural learning experiences or genetics.
Of all the odors, people ranked vanilla as the most pleasant smell. The second favorite was ethyl butyrate, which has a peach-like scent. Mostly people considered isovaleric acid — found in cheese, soy milk, apple juice, and foot sweat — to be the worst odor.
The team’s next step is to understand why humans evolved to universally like or dislike certain smells and what goes on in the brain when we smell a specific odor.
The study is published in the journal Current Biology.