Pink or red for a fruity odor; brown or orange for a musty one. Smells can bring colors to mind, but are those associations the same for everyone?
A 2014 study tested the same 14 odors in six groups with different cultural backgrounds. Color choices showed some consistent biases within each group, but the overall patterns of odor–color associations differed between groups.
Choosing colors without naming the odors
The study aimed to explore whether odor–color correspondences are broadly shared or partly learned through everyday experience and language. Comparing separate studies is difficult because their odor materials, concentrations, and questions differ, so this study used the same samples and task throughout.
There were 122 participants in total. The groups included Dutch, German, Malay, Malaysian Chinese, and US participants, plus people born and raised in China who had lived in the Netherlands for less than two years. There were 20 participants per group except for the US group, which had 22. Six groups did not mean six countries: the distinctions reflected places of residence and backgrounds of upbringing.
The samples were fragrances designed to represent fruit, flowers, candy, wood, hazelnut, rice, soap, vinegar, burnt smells, vegetables, fish, meat, plastic, and mustiness. Participants smelled them one by one from pen-like containers and selected three colors that best matched and three that least matched each odor from 36 colors on a screen. They did not rank the three colors within each selection.
No names were provided for either odors or colors, and both the color layout and odor order varied. The design aimed to minimize cues introduced by assigning specific words to odors.
Color choices were not random within each group
Analyses combining matching and nonmatching colors reportedly found significant departures from a random distribution for each odor in every group. The text gives fruity odors tending to evoke pink and red, and musty odors tending to evoke brown and orange, as examples.
Table 1, which reports these tests, leaves a reporting question: the US and Malaysian Chinese test values are identical for all 14 odors. The text’s statement that every group showed a bias should be read with that reservation. The classification performance and cross-cultural pattern comparisons below are separately reported analyses.
Shared color choices, however, are not the same as being able to identify an odor from those colors alone. The researchers therefore also examined whether a classifier trained on some participants’ color choices could identify which of the 14 odors the remaining participants had smelled from their response patterns.
Against a chance level of about 7%, accuracy was 22% for the US group, 19% for the German group, 16% for the Malaysian Chinese group, and 15% for the Dutch group, all significantly above chance. The Malay group and the China-raised group living in the Netherlands each scored 9%, neither significantly above chance.
Thus, although every group showed biases in color selection, groups differed in how strongly participants shared odor-specific color patterns. These figures describe statistical classification of response patterns, not participants’ ability to name odors themselves.
Nearby countries or shared origins did not necessarily mean similar color associations
The cross-cultural comparison examined more than which color was most popular. It considered the full set of relationships describing how similarly different odors evoked colors. For example, in the US group, fruit, flower, and candy odors formed a cluster of similar color choices.
These relational patterns were especially similar for the US–German and German–Malay pairings. The largest differences were found for the Malay–China-raised-in-the-Netherlands pairing and the Dutch–Malaysian Chinese pairing.
The researchers had initially expected similarities between geographically close groups such as the Dutch and German groups, and between groups with Chinese backgrounds. Those predictions were not supported. The associations did not form a simple map in which people from the same region matched odors to the same colors.
Nonmatching colors also help characterize an odor
An innovative feature of the study was asking about nonmatching as well as matching colors. Even if the same red is frequently chosen for two odors, differences in other selected or avoided colors can reveal different ranges of associations.
In fact, analyses using only matching colors captured pattern similarities less well than analyses using both kinds. However, the reduction in available data also matters, so this does not establish that asking about nonmatching colors is always the better method. The result highlights the value of examining combinations of colors rather than assigning each odor a single color label.
Experience may contribute, but culture need not be the only cause
The differences between groups fit the idea that experience and learning contribute to odor–color correspondences better than the idea that all such links are innately fixed. Encounters with foods, scented products, and everyday objects are possible sources of these associations.
The comparison did not disentangle age, travel experience, cooking frequency, and similar factors from cultural background. Nor could it separate direct odor–color links from color choices mediated by perceived odor pleasantness or intensity. Caution is therefore needed before treating one group’s responses as a property shared by everyone in its society.
Summary
Choices of colors that matched or did not match odors showed shared biases within each of the six groups. Yet the relationships among odors’ color associations differed between groups, and nearby countries or shared origins did not necessarily produce similar patterns.
Odor–color combinations contain both shared cues and aspects that may change with experience. The study highlights the importance of considering whom an odor is being communicated to and examining the range of associated colors rather than just a single color.
The research received funding from Occidental College, Wageningen University, the Ready Mind Project, Germany’s LOEWE research program, and other sources. Unilever supplied the odor samples. The authors declared no competing interests and stated that funders had no role in study design, analysis, the decision to publish, or related activities.
Reference
Levitan CA, et al. (2014). Cross-Cultural Color-Odor Associations. PLOS ONE, 9(7), e101651. Original research article and open full text
