Warning: this article contains a word that you might find offensive. In fact, some readers might find it so deeply unsettling that they might begin to wonder about the cause of their aversion. What is it about this word that generates such a visceral experience of revulsion and discomfort? Is it something about the particular combination of sounds it forces us to utter? Maybe something about the conceptual associations that it evokes? What proportion of the population also feels this way? Is this only true of certain kinds of people and not others?

The word in question here is “moist”, and apparently 20% of the population equate hearing it spoken with fingernails on a chalkboard. An aversion to the word has become somewhat of a cultural phenomenon, with celebrities decrying it as an abomination of the English language, and outlets from New Yorker to People exploring its uniquely disturbing properties.

Though on its face the thought of devoting a program of research to discovering why people hold such an aversion seems like the kind of topic likely to appear in the next round of arguments trying to defund social science research, there are interesting questions to be answered here that shed light on basic psychological processes. New research from Paul Thibodeau at Oberlin College has attempted to understand these processes and his initial work has suggested that the cause of the aversion may not be what most people think.

Thibodeau considered several possible alternative explanations for the origin of this aversion. First, there may be something about the word’s phonological properties – the “oy” sound followed by the “ss” and “tt” – that just make it seem icky. As someone who has spent the last ten minutes mouthing the word silently to himself at a coffee shop, I can tell you that this explanation holds at least some intuitive appeal. There’s something a little bit vulgar about the puckering configuration of the lips required by “moi” that makes one feel just a bit uncomfortable. And it will certainly make the people around you uncomfortable if you repeat that movement for a prolonged period of time in a public space. If this phonological hypothesis is the correct explanation, then you would expect other words with similar properties to be equally aversive (e.g. hoist, joist, rejoiced).

A second possibility has to do with the concepts that people tend to associate with the word. Though “moist” has many uses in the English language, it may be predominantly associated with thoughts of sex and other bodily functions. Concepts that some people might find uncomfortable. If this semantic hypothesis is correct, then people who show moist aversion should also be averse to other words related to bodily functions (e.g. phlegm, vomit, puke).

Dr. Thibodeau designed five experiments to tease apart these two competing explanations. To do so, he presented participants with a list of 29 target words and asked them to judge the words along six dimensions: how often they used the word, how often they encountered the word, aversion to the word, its positivity/negativity, how exciting or arousing it was, and how easily it evoked an image in their mind. Included in the set of 29 were words that were either phonologically (e.g. hoist, joist, etc.) or semantically (e.g. words about sex and bodily function) related to “moist”. Thibodeau hypothesized that if the aversion to moist is rooted in phonology, then people averse to it should also show aversion to words with similar properties. But if the aversion is semantic, then those averse to it should show similar patterns of aversion to other words linked to sex and body function.

In addition to simply asking people for their judgments about the different words, the hypothesis was also tested using a free association task, in which participants were asked for the first word that came to mind after seeing each target word, and a surprise recall task, in which participants were asked to write down as many of the 29 words they could remember at the end of the experiment. The thinking here was that participants should show similar patterns of free associations and similar rates of recall across phonologically similar words, if that was the explanation for moist aversion, but similar patterns across conceptually similar words if that was the explanation.

Several consistent results emerged across the five studies. First, it seems that attitudes towards moist are indeed driven by visceral responses to the word. This was reflected in how aversive participants rated the word, as well as the kinds of responses generated in the free association and recall task. Moist-averse participants showed strong free-response associations between “moist” and visceral expressions of disgust like “eww” and “yuck”, and people who reported an aversion to “moist” were about 25% more likely to accurately recall having seen the word (suggesting it had more of an emotional impact on participants).

Second, those averse to the word “moist” also showed aversions to semantically related words and words related to bodily function, supporting the semantic association explanation of moist aversion. No support was found for the phonological hypothesis. Finally, participants seemed to have little insight into the reason for their aversion to the word. Those most averse tended to identify the phonological properties of the word as the cause of their aversion, as opposed to its semantic association with bodily functions.

This is compelling initial support for the cause of word aversion, but further research needs to be done. A separate possible explanation not tested in the current studies, but which the author acknowledges, is rooted in the facial feedback hypothesis. This hypothesis suggests that facial movement can influence emotional experience. In other words, if facial muscles are forced to configure in ways that match particular emotional expressions, then that may be enough to actually elicit the experience of the emotion. On this explanation, saying the word “moist” might require the activation of facial muscles involved in the prototypical disgust expression, and therefore trigger the experience of the emotion. This could explain the visceral response of “yuck” people get when they think of the word. Separate research has identified the particular facial muscles involved in the experience and expression of disgust, but no research as of yet has tested whether the same muscles are required when saying “moist.”

Of course, different explanations might be needed to account for aversions to other commonly used words such as “luggage,” “slacks,” and “crevice,” and research might profitably explore the unique properties of each. Let’s just take a moment to acknowledge and thank Dr Thibodeau’s research assistants in advance for having the courage to be on the front lines in what is surely deeply awkward and uncomfortable work.