Chromatic Classification of Odor Identities

Scientists are smart - the way they figured this out is really clever, because they literally "blinded" the participants to the study; they're not asking you to tell them what color comes to mind, they ask you to just choose the neutral gray. This is how they figure out racial bias too:

Our sense of smell alters the colors we see, show scientists

Oct 2023, phys.org

https://medicalxpress.com/news/2023-10-scientists.html

"In a previous study, we had shown that the odor of caramel commonly constitutes a crossmodal association with dark brown and yellow, just like coffee with dark brown and red, cherry with pink, red, and purple, peppermint with green and blue, and lemon with yellow, green, and pink," explained Ward.

Ward and colleagues tested 24 adult women and men between 20 and 57 years of age with one of six odors chosen at random from caramel, cherry, coffee, lemon, and peppermint, plus odorless water as a control, and asked to manually adjust two sliders - one for yellow to blue, and another for green to red - to change its color to neutral gray. 

Participants had a weak but significant tendency to adjust one or both of the sliders too far away from neutral gray. For example, when presented with the odor of coffee, they wrongly perceived 'gray' to be more of a red-brown color than true neutral gray. 

An exception was when the odor of peppermint was presented: here, the participants' choice of hue was different from the typical crossmodal association demonstrated for the other odors. As expected, the participants' selection likewise corresponded to true gray when presented with the neutral scent of water. 

via John Moores University in Liverpool: Ryan J. Ward et al, Odors modulate color appearance, Frontiers in Psychology (2023). DOI: 10.3389/fpsyg.2023.1175703

https://dx.doi.org/10.3389/fpsyg.2023.1175703

Image credit: AI Art - Face of Quasiparticles - 2023

Crossmodal Perception and Cultural Difference

Infrared Central Park by Paolo Pettigiani circa 2016, via wired

It is not often that we get to hear scientists talking about the language of smell, so let’s hear from Asifa Majid, a scientist who studies, among other things, the language of smell as she talks to cognitive scientist Jon Sutton about language and thought:

“For example, in English sweet (taste) can also be used to describe people; i.e. a ‘gentle, kind or friendly’ person. But in Hebrew when sweet is used metaphorically it refers to ‘inauthenticity’. A spicy person in English might be considered ‘full of spirit’, but a spicy person in Hebrew would be someone ‘intellectually competent’. If a young man in Guhu Samane (Papua New Guinea) described a group of girls as sweet, the man could relate to them as sisters, and approach them. But if the girls were described as bitter, that would be because they are potential wife material (because they come from the appropriate clan), and so the young man should be cautious and keep his distance. These are all examples of how taste vocabulary can be used for traits and characteristics of people. Metaphor is pervasive in language.”

- taken from The Content of Minds in The Psychologist, July 2016

The entire language of smell is a proxy for other senses. All smells are named for what they’re like, for the experiences they evoke. To name a smell, to verbally explore what a thing smells like, is to reveal something deep inside our minds and at the core of our culture.