tO THE SWEDENThere are few scents more delightful than the scent of surströmming, a type of fermented herring. For most non-Swedes, there are probably few smells more repulsive – the fish has been variously described as smelling like rancid kitty litter, faint feces, or even corpse-like. In determining which scents people like and which don’t, surströmming suggests that culture must play a major role.
However, new research suggests that this is not the case. Artin Arshamian, a neuroscientist at the Karolinska Institute in Sweden, and Asifa Majid, a psychologist at the University of Oxford, started with the expectation that culture would play an important role in determining pleasant smells. This was not just because of examples like that of fermented herring. They had noticed from their own previous work that people from different cultures described smells differently. They also knew from previous experiments by other researchers that culture was important in determining what types of faces people liked. So they expected to see a similar phenomenon with smells.
To study how smell and culture relate, Dr. Arshamian and Dr. Majid nine different groups of people with ten scents. These ranged from pleasant-smelling vanilla extract to isovaleric acid, the chemical responsible for the disgusting smell of stinky socks. More intermediate odors, which the team thought might divide opinion, include octanoic acid with its moderately rancid odor; the sweet-smelling eugenol, which comes from cloves; and octenol, a musty and earthy odor found in many mushrooms.
The cultures that did the smelling also varied widely. These included hunter-gatherer communities along the coast of Mexico, subsistence farmers living in the highlands of Ecuador, coastal collectors, Swedish horticulturists living in the tropical rainforests of Malaysia, and city dwellers from Thailand and Mexico City. All 235 participants were asked to rank odors by pleasant. The team compared their results with previous work on New Yorkers exposed to the same odors.
Register current biology this week, the researchers noted that the smells’ pleasantness rankings were remarkably consistent no matter where people came from. The smell of isovaleric acid was maligned by the vast majority of participants, with only eight giving it a score of 1 to 3 on the pleasantness scale (1 being very pleasant and 10 being very unpleasant). On the other hand, more than 190 people gave vanilla extract a score of 1 to 3 and a small minority, just 12 people, found it repulsive enough to give 8 to 10. Overall, the chemical makeup of the fragrances presented by the researchers explained 41% of the responses participants had. Cultural education, on the other hand, accounted for only 6% of the results. dr. Arshamian and Dr. Majid point out that this is very different from how visual perception of faces works – in which case a person’s culture accounts for up to 50% of the explanation for which faces they like.
Still, although culture didn’t shape the perception of smells in the way it’s known to shape the perception of faces, the researchers found an “eye of the beholder” effect. Random, of which Dr. Arshamian and Dr. Majid suggesting it must come from personal preferences learned from outside the individual culture accounted for 54% of the variance in which people like scents. “The spectator’s olfactory bulb” doesn’t slip off the tongue so easily, but it also turns out to be a real phenomenon.
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This article appeared in the Science & Technology section of the print edition under the headline “A Rose by Another Name”