Scientists say the types of scents people like or dislike tend to be common among individuals of different cultural backgrounds, which may point to an evolutionary basis for what appear to be universal scent preferences.
In a new study, researchers asked individuals from 10 distinct cultural groups – including a number of indigenous hunter-gatherers and traditional farming communities, as well as modern urban dwellers – to smell 10 unique fragrances and rank them in order.
“We wanted to examine whether people all over the world have the same smell perception and like the same types of smell, or whether this is something that has been culturally learned,” says neuroscientist Artin Archamian, from Karolinska Institutet in Sweden. But we can show that culture has little to do with it.”
The researchers traveled far and wide, collecting data from field work in many cultural settings, which represent diverse lifestyles across Thailand, Mexico, Ecuador and the United States, and include deserts, tropical rainforests, highland climates, coastal regions, and more.
The research included a number of hunter-gatherer groups (including the Semaq Beri people from the Malay Peninsula in Thailand), as well as several horticultural and agricultural communities (such as the Chachi people in Ecuador), and a group of participants from New York.
In each location visited, participants – more than 280 individuals – were provided with 10 randomly arranged diffusers. They were asked to smell each one in turn, from the most pleasant to the unpleasant.
The scent generally rated as the most pleasant was vanillin (the main component of the vanilla extract), while the next most common scent was ethyl butyrate (which has a fruity aroma and is often used as a flavor enhancer in fruit-flavored foods), and the third is linalool, which has a distinct floral scent.
While much previous research has examined the field — looking at how smell perception is informed by cultural associations — the researchers here say that previous experimental approaches have failed to study a sufficiently diverse cultural spectrum.
Ultimately, we might expect people’s classification of smell (smell valency) to reflect a combination of their cultural traditions, personal sensitivities, and general preferences (ostensibly based on the molecular traits of smell), but the extent of each of these effects has so far been unclear.
Archamian’s team found that the influence of cultural traditions plays only a small role in people’s preference for smell, with ratings of odor valence strongly and positively correlated across all cultures measured.
When people rated individual odors differently from each other in terms of perceived pleasure, the researchers say that participants’ culture explained only about 6% of the variance, while 54% was due to people’s individual preference, and the molecular profile of a chemical odor explained about 40% of the variance.
In other words, while people can arrange different scents differently, most of the differences observed appear to be a matter of personal preference, not a reflection of culture; At the same time, there is a lot of cross-culturalism in terms of what people like and don’t like.
The researchers explain: “There was significant global consistency. Taken together, this shows that human olfactory perception is severely restricted by universal principles.”
As for the reason why the perception of odors seems at least somewhat universal across cultures – and depends on the physical and chemical properties of the smells themselves – it is plausible that a preference for certain chemical odors may have served an evolutionary purpose in our history, and somehow increased our chances of survival in Long forgotten times.
And if so, the results here could help us study the possibility further, the researchers suggest.
The results are reported in Current Biology.