When people living far apart smell the same odor, do they experience it in the same way? Different foods and local plants might change what a smell brings to mind. But those differences need not appear only in whether people like or dislike it.
In September 2025, an international team led by Eva Drnovsek published a study of odor perception in 909 people from 16 regions. Ratings across 12 dimensions, including pleasantness, intensity, and food-related qualities, showed a stronger association with region for intensity than for pleasantness. Most differences, however, could not be explained by region, age, and gender alone.
Smelling eight odors along 12 dimensions
Participants were aged 18–60 and lived in 16 regions, including Japan. Local teams recruited participants in urban areas, such as Tokyo in Japan and Dresden in Germany. The original survey covered 18 regions, but after excluding regions with too few participants or missing ratings, 909 people were included in this analysis.
Participants smelled eight odors using pen-shaped odor-delivery devices. The substances included banana-like isoamyl acetate and grassy cis-3-hexenol. This was not a comparison of preferences for finished perfumes, but a study of perceptions of eight prepared odors.
They rated 12 attributes, such as pleasant, intense, appetizing, edible, and burnt. Participants received instructions in their native language and marked the degree of each attribute on a line corresponding to a scale from 0 to 100. Eight odors multiplied by 12 attributes yielded 96 ratings per person.
Turning each person’s perceptions into a profile
How can so many ratings be compared? The researchers’ main analysis used a measure called an olfactory perceptual fingerprint. Here, it is helpful to think of it as a profile summarizing each person’s perceptions across 12 attributes.
First, for each attribute of each odor, the researchers subtracted the mean rating across all participants from that person’s rating. For intensity, for example, this indicates how much stronger that person rated an odor than the overall average. Averaging this difference across the eight odors gives the person’s intensity value. The same calculation was performed for all 12 attributes.
This method helps distinguish the tendency of a particular odor to receive high ratings from an individual’s tendency to rate it higher than the group as a whole.
How large was the association with region?
Among the 904 participants with complete gender data, analysis of variation across the full 12-attribute profile found that age explained 1.1% and gender 0.3%. After accounting for those two variables first, region explained 9.6%.
The dispersion of participants’ ratings also differed between regions, so this result cannot be attributed solely to the effects of culture itself.
The figure of “about 10%” refers to variation in the profiles constructed in this study. It cannot be rephrased as “culture determines 10% of odor preferences.” Nor can the unexplained remainder simply be regarded as innate individual differences: it also includes measurement variability and factors not examined here.
The study also examined a different profile based on how similarly participants rated the eight odors to one another. Region explained 8.2% of the variation in this profile. Although an association with region remained when the method of summarizing ratings changed, most variation was unexplained in both cases.
Differences were more apparent in intensity than pleasantness
Looking at the 12 attributes individually, the strength of their association with region varied. A statistical measure of effect size was 0.17 for intensity and 0.08 for pleasantness. In these ratings, how strong an odor seemed captured regional differences more readily than whether it was pleasant.
This does not mean that people in one region smelled odors “twice as strongly.” Nor was this a test of the sensitivity of the nose itself. What was compared was how intense people rated the odors actually presented to them.
When asking someone about a scent, we tend to ask, “Do you like it?” This study shows how broader questions, such as “How strong is it?” or “Does it seem edible?”, can draw attention to differences in perception that preferences alone do not reveal.
Conclusion
There are many commonalities in odor perception even among people living in distant regions. That is how the researchers interpret these findings across 12 dimensions, rather than likes and dislikes alone. At the same time, regional differences were larger for intensity ratings than for pleasantness.
However, this was a survey of urban participants rating eight odors. It does not establish national patterns or the causes of the differences. Region alone cannot explain each individual’s perceptions either. The study illustrates the value of considering both shared aspects of odor perception and differences that emerge in intensity.
References
Authors: Eva Drnovsek et al.
Paper title: Demographic and geographical determinants of human olfactory perception of 909 individuals inhabiting 16 regions
Journal: iScience, 28, 113455
First published online: September 18, 2025 (issue date: October 17, 2025)
DOI: 10.1016/j.isci.2025.113455
https://doi.org/10.1016/j.isci.2025.113455
Original full text: https://depot-e.uqtr.ca/12613/1/FRASNELLI_J_30_ED.pdf
Original paper license: CC BY 4.0. This article independently explains the research and does not reproduce figures or tables from the original paper.
