An olfactory demography of a diverse metropolitan population

Abstract

BackgroundHuman perception of the odour environment is highly variable. People vary both in their general olfactory acuity as well as in if and how they perceive specific odours. In recent years, it has been shown that genetic differences contribute to variability in both general olfactory acuity and the perception of specific odours. Odour perception also depends on other factors such as age and gender. Here we investigate the influence of these factors on both general olfactory acuity and on the perception of 66 structurally and perceptually different odours in a diverse subject population.ResultsWe carried out a large human olfactory psychophysics study of 391 adult subjects in metropolitan New York City, an ethnically and culturally diverse North American metropolis. 210 of the subjects were women and the median age was 34.6 years (range 19–75). We recorded ~2,300 data points per subject to obtain a comprehensive perceptual phenotype, comprising multiple perceptual measures of 66 diverse odours. We show that general olfactory acuity correlates with gender, age, race, smoking habits, and body type. Young, female, non-smoking subjects had the highest average olfactory acuity. Deviations from normal body type in either direction were associated with decreased olfactory acuity. Beyond these factors we also show that, surprisingly, there are many odour-specific influences of race, age, and gender on olfactory perception. We show over 100 instances in which the intensity or pleasantness perception of an odour is significantly different between two demographic groups.ConclusionsThese data provide a comprehensive snapshot of the olfactory sense of a diverse population. Olfactory acuity in the population is most strongly influenced by age, followed by gender. We also show a large number of diverse correlations between demographic factors and the perception of individual odours that may reflect genetic differences as well as different prior experiences with these odours between demographic groups.

The smell of us – crowdsourcing human body odor evaluation

“…Rather we observed a uniform distribution of smeller scores, with the exception of extreme values that were more likely to be selected. In contrast, other large-scale odor analysis projects have observed normal or bell-shaped distributions of pleasantness scores (Keller et al, 2012). This difference may be caused by the slider tool used to collect user inputs.…”

“…Individual smellers will differ in their genetics (Keller, Zhuang, Chi, Vosshall, & Matsunami, 2007), level of training (Cain, 1979), previous experience with an odor (Poncelet et al, 2010), and demographic profile (Keller, Hempstead, Gomez, Gilbert, & Vosshall, 2012). To an unknown extent, odor perception is the product of cultural forces beyond the scope of chemistry or physiology (Agapakis & Tolaas, 2012).…”

“…Women also show a greater interest in olfaction across cultures (Seo et al, 2011) and have a higher neuron density in the olfactory bulb (Oliveira-Pinto et al, 2014), which may contribute to a greater odor sensitivity. Gender-based differences have been shown in the perceived pleasantness of many odorants (Keller et al, 2012) including other body odors (Doty, Ford, Preti, & Huggins, 1975), but it is unknown to what extent these differences are biological or cultural. Surprisingly, deodorant use was found to have no effect on body odor intensity and a negative impact on pleasantness.…”

Understanding smell—The olfactory stimulus problem

“…In insects, assays and highthroughput methodologies can be applied for measuring odor attractiveness (Steck et al, 2012). Recently, large-scale psychophysics studies have been applied in humans (Keller et al, 2012), and it is to hope that more studies will go in a similar direction.…”

Individual Differences in Retronasal Odor Responsiveness: Effects of Aging and Concurrent Taste

“…Accordingly, the valence of a food odor modulates the acceptance and rejection of the food. Beyond individual differences in the perception of odor quality, sensitivity to odors can vary across individuals as well (Berglund et al 1971;Burdach et al 1985;Powers and Shinholser 1988;Wysocki and Gilbert 1989;Walker et al 2003;Keller et al 2012). For example, sensitivity to vanillin, a common food odor, varies as much as 5 orders of magnitude across individuals (Powers and Shinholser 1988).…”