Through a unique combination of experimental methods and field studies, a research team led by the Karolinska Institute in Sweden and the University of Oxford in the UK has found that what smells we like or dislike is primarily determined by the structure of particular odor molecules. Thus, people around the world seem to generally share odor preferences regardless of their cultural background.
“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,” said study lead author Artin Arshamian, an expert in Medical Epidemiology at the Karolinska Institute. “Traditionally it has been seen as cultural, but we can show that culture has very little to do with it.”
The scientists selected nine indigenous communities representing different lifestyles, including four hunter-gatherer groups and five groups engaging in various forms of fishing and farming activities. In total, 235 individuals were asked to rank different smells on a scale from pleasant to unpleasant.
“Since these groups live in such disparate odiferous environments, like rainforest, coast, mountain, and city, we capture many different types of ‘odor experiences,’” said Dr. Arshamian.
Although the results showed variations between individuals in each group – which can be largely explained by molecular structure (41 percent) and by personal preference (54 percent) – there was a strong global correspondence on which odors were considered pleasant or unpleasant.
Most of the participants ranked the smell of vanilla as the most pleasant, and that of isovaleric acid – found in foods such as cheese, soy milk, or apple juice, as well as in foot sweat – as the least pleasant. According to the researchers, a possible reason why people like some smells more than others regardless of their cultural background is that such odors may have increased the risk of survival during human evolution.
“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. 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,” Dr. Arshamian concluded.
The study is published in the journal Current Biology.