We all know people who hate the word moist, But why are they okay with synonyms like damp or muggy or wet. What's going on in their brains and what does this have to do with shapes or autism or synesthesia. Welcome to another episode of Inner Cosmos with me David Eagleman, all about the magical three pounds of matter that constitute your reality. In today's episode, we're going to talk about a wild and relatively new example of the differences between people's internal cosmoses. We're going to talk about word aversion. Imagine that you find a tribe of people with little contact with the outside world, and they show you that they have some shapes that they draw. One of them is a round, blobby object, and another shape is a sharp, spiky star pattern. Now you figure out that one of these they call bouba and the other they call kiki. And the question I have for you is which do you think is which is the blobby thing called kiki and the starburst thing is called buba? Or would you guess it's the other way around? If you are like essentially everyone else on the planet, you guessed that the blobby object was called buba, and the sharp object was called kiki. Now, the buba kiki effect was something studied in a psychology paper a century ago, and it was a little surprising because essentially everybody gives the same answer, linking the soft sounding word with the soft looking object and vice versa. But this is surprising because in general, there's really not supposed to be a relationship between the sound of a word and what it looks like. But what this tells us is that we sometimes have relationships across the senses. And if you heard my episode on synesthesia, episode four, you'll know that a fraction of people, probably between five and ten percent, have this kind of blending of the senses in more unusual ways. For example, they might see letters and that triggers a color experience for them, where they might hear something, and that triggers a visual shape for them where they might taste something and that puts a feeling on their fingertips and so on. Now, I'm going to come back to this issue of synesthesia. That want to return to the issue of the sound of a word. So let me begin by pointing out that in general, the sound of a word has no relationship to its meaning. You can call a car an automobile or a vehicle or whatever. We don't just call it a room. So the sound that we make with our mouth car is usually quite arbitrary, and you can see this by comparing across languages, where you can call it a mahonite or che or vatur or whatever. So the sound of a word and its meaning are typically unconnected. But it's not always so simple, because sometimes we do find a strange relationship between sound and meaning. Think of on amotopeia, where a word imitates phonetically, in other words, in sound what it describes. For example, for a gun firing we say bang. It's a mapping between the sound and the meaning that's not arbitrary. Or describing the sound a fly makes as buzz, or describing the sound of cat makes as hiss, And there are lots of examples of onomatopeia, like the sound of something breaking we say crash, or the sound of something plunking into the water, or the sound of a clock we use TikTok, or when we think about the sound of cat makes in English, we say meow, or for a dog woof or a frog ribbit. These are all examples of words that have a phonetic relationship with the thing they describe. In other words, they sound like it. And sometimes these relationships between sound and meaning are even more subtle. There's something called phonus themes, which are clusters of sound that you find in common across related words in a language. So in English we find the sound made by gl or ghul is associated with light or shining. Think about words like gleam, glitter, glisten, glow, and more loosely, words like glorious or glamorous. Across all these words, which are cousins in meaning, you find the same sound. So linguists are aware that sometimes there are mappings between the way a word sounds and its meaning, but there's not much known about the more specific relationship between word sounds and an unusual emotional response that can be triggered. So I got interested in this question because something didn't escape my notice and probably not yours either, And that's the fact that some fraction of my friends can stand certain words. This is something that struck the author George Saunders when he was giving a reading of a new book he'd just published, and he was surprised that people in the audience didn't really seem to mind his really rough language with the cussing and the sex scenes and so on. But two people told him that they really hated that he used the word moist. His cousin who was there, said it made her feel a little physically ill when he used it. And then he gave a reading in a different location, and his sister was there and she said the same thing. Her reaction wasn't to the risk a language and scenes, but to a single word moist. Now, as it turns out, lots of people, people you know or people you love, they hate the word moist. It triggers a feeling of aversion or disgust. For some people, this makes cooking shows unwatchable, or they can't read an article about forestry and soil or whatever. Moist is famous for being a word that many people despise, but moist is just one word of many consider the word tender, the word slacks, the word tissue. Now, many of you listening don't mind these words at all, and others are disgusted by these or consider words like the yellow thing inside an egg, the word yoke. Some people hate that word and many other words come up in our studies as being unusually hated words like nourish, bulge, pulp, giggle, fluffy nugget, or there was a guy who got interested in astronomy but got put off by the term globular cluster. So this phenomenon is called word aversion, and what it involves are words that are neutral in their meaning, like tissue or a globular cluster or whatever. There's no particular emotional meaning to the word, but it triggers a feeling of repugnance in some fraction of the population. My colleague Mark Lieberman, who's a linguist at the University of Pennsylvania, he set out to give a clear definition of word aversion. He said, it's quote a feeling of intense, irrational distaste for the sounder sight of a particular word or phrase, not because its use is regarded as etymologically wrong or logically wrong or grammatically wrong, nor because it's felt to be overused or redundant or trendy or non standard, but simply because the word itself somehow feels unpleasant or even disgusting. End quote. So I want to be clear that there are all kinds of words that you can hate for other reasons. You might find some word snobbish or foolish, or you might think that it's being used incorrectly. But those are all different from word aversion, and we're not talking about politically charged words like words that are sexually taboo or religiously taboo, or ethnic slurs or other offensive words. Word aversion is a different thing. And Lieberman points out that while people say they hate words like moist, it's not the angry kind of hate. It's more the cringe, shudder, shiver, gives me the willies kind of hate. As an example, one person online said, and I quote the word panties grosses me out, and hypercorrect usage of whom annoys me. But the feelings I get when I hear them are two distinct sensations that I would never confuse end quote. So the scientific mindset cares about this distinction and understanding what is going on here, And my lab got interested in this because we saw that word aversion provided an inroad to study this strange and unexpected relationship between sound and emotion. Now, before we dig in on this, I want to fully flesh out word a version with some examples. And there's a ton of information about word a version spread all around online forums. So I'll just give you some examples to enhance our intuitions about this. One woman named Lisa posted quote, there's one word that I hate above all others. If I come across it, I must immediately declare my hatred of it to anyone who is there to listen. If there's no one around, I'll resort to primal arguing and hit the page where the word resides. The word is hard scrabble. I don't have a logical reason for hate this word. I haven't had a traumatic experience with it in the past. I simply find it revolting. It's ugly. End quote. Someone else posted luggage. Can't stand that word luggage. It just feels gross. End quote. Someone else says I hate the word pugilist. Another says tissue shiver. It gives me the willies. Someone else writes, my girlfriend's sister hates the word moist fist used together. So if you start looking around, you'll find literally thousands of posts and discussions about this, which, from a scientific point of view, suggests that there's something to be understood here. Now. Quite commonly, when you look through these forums, you see words like moist and fleshy, and panties, but there are lots of other words that are less expected. One woman reports, quote, my mother hated gut, would not let us say it, as if it were the worst word in English. End quote. Other people online give examples like goose, pimple, or a chunk or wedge, or meal or baffle or squab or cornucopia. One person pointed to the word giggle and said he hates that word quote with the concentrated hatred of a thousand hate filled sons. End quote, fudge conduit. One person said his aversive words were a gig motif and whimsy. He says, quote no rational reason, just hate them unquote. Now there are a few important clues that we need to note here. The first thing is that not everyone experiences word aversion. In fact, most people don't, and this is something I'll come back to in a bit. But of course it's hard to know what fraction of the population has this. So about a decade ago, Mark Lieberman decided to take a cre creative shot at gathering some data. He noted that the problem with scraping people's online postings about word a version was that it can't tell you what fraction of people experience it. In other words, how many people have word a version? Because if a commenter writes how aversive moist is to them, you don't know if that poster represents one out of five people or one out of five hundred. So Lieberman had an interesting idea to look at famous authors and see how often they use the word moist. Now, just a side note that this is the kind of experiment that you can do now, but you couldn't do this twenty five years ago because you need to analyze every word of the entire corpus of each author, everything they've ever written. Nowadays this seems trivial, but I just want to point out that this kind of questioning and answering was just not available even a generation ago. So we're living in terrific times, Okay. So he tapped into projects Gutenberg, which was an early project to digitize books and make them searchable, and using that approach, which was still a little rough back in twenty twelve. When he did this, he analyzed the complete works of fifty authors. So this was about one hundred and twenty five million words, with an average of about two and a half million words per author, and he found that on average, there were about six appearances of the word moist per million words. Now here's the interesting part. He found that for some authors, like Jane Austen, for instance, there was never a single mention ever of the word moist. If it was just a random draw, the fact that she never ever used moist would have a probability of happening by chance of zero point seven, in other words, a very low probability of that happening just by chance. On the other hand, some authors use it plenty. The short story writer Brett Hart from the eighteen hundreds used fifty six moists, or about twenty two times for every million words. But compare rehtt Hart to Mark Twain, who lived at almost exactly the same time. Mark Twain only used the word moist two times in his entire career, and he wrote a lot more so. Mark Twain used only zero point five moists per million words, or forty four times less often than Brett Hart. And by the way, Lieberman points out that one of Twain's uses of the word moist hardly counts because it was part of a long made up name of an elephant, and the other use of moist Lieberman asks with a question mark whether that single use of the word might have been in by an editor. In any case, this kind of literary detective work reveals that some authors are happy to use the word and others avoided completely in every sentence they've ever published in their entire career. Now you might point out that maybe these authors just wrote about different topics and so moistness just didn't come up. So to address that, Lieberman quantified other humidity related words like wet, damp, or dry or arid, and he did the calculations on those, and he found that Mark Twain used plenty of such words, He had about half the rate of Brett Hart, even while his use of the particular word moist was forty four times less frequent. So by looking at someone's entire corpus of writing, you might be able to tell something about who hated moist and who didn't care. Now, why is there any difference between people? Well, let's take a quick dive version into another area that my lab is studied for a long time, sinesthesia. These reports of word aversion immediately grabbed my attention because in sinesthesia, as I mentioned at the beginning, we see a cross blending of the senses. So sounds of certain words might trigger a color experience, or a texture or a taste, and word aversion sounds quite a bit like that. We're talking about sensory experiences that we usually consider as separate and distinct, but in some people the lines between these different sensations aren't so rigid. And so although we typically think of synesthesia as triggering colors or sounds, there certainly seem to be examples where any emotion is triggered, and often it's an emotion of aversion or disgust. So something I've previously suggested in the literature is that the sensory processing disorder that we see in autism is actually a kind of synesthesia. Sensory processing disorder is when you see a kid who can't stand certain sounds it drives them nuts, like the sound of a vacuum or the sound of a zipper or somebody chewing or so on. So I think that is a form of synesthesia, But instead of a region of the brain like color getting triggered, it's regions involved in aversion. There are a whole bunch of circuits in the brain involved in pain and disgust or itch or whatever. So if sensory processing disorder is a form of synesthesia, you can see why word a version grabbed my attention. I wondered if there might be some sinesthetic relationship here, that a person might get this cross blending of different senses with the sound of the word and an emotion that that triggers. Instead of colors, one gets a feeling instead of indigo blue, one gets the creeps. So I got very interested in understanding what was going on here, And the first thing I zoomed in on was that for people with word aversion, it doesn't happen for all words, just certain words. So how could we drill down on that? First I found in the literature that there had been a study on word aversion. A researcher named Paul Thibodeau explored what he called moist aversion, and it was binary, in other words, just based on your yes or no answer to the question would you characterize yourself as being particularly averse to the word moist. But we know that word a version is much broader than moist aversion. Many other words appear all the time in self reports of word aversion, like tender or slax or nugget or tissue. So Thibodeau's study was an important first step in understanding word of version, but it left a lot unanswered. Okay, so what were the next steps for us? If aversive words were only words like moist, we might think it's some reference to the meaning of the word. But something I noticed is that people often clarified that they were fine with alternative words or synonyms. Even if they hated the word panties. They were fine with words like undies and thong, just not panties. And even if they hated the word moist, they were fine using synonyms in its place, like damp or humid, or muggy or wet. So that suggests it's not just about the meaning, but perhaps there was something else going on. And with so many of the other words that show up on these lists, it's essentially impossible to think of any meaning, even several degrees away that could possibly be triggering. Who has anything against the word giggle or wedge or luggage. So one possibility that suggested itself is that it's the sound of the word, not just the meaning, that was the basis for the aversion. And so we got interested in this question, and I started looking into this with a student of mine, Hannah Bosley, who's now a clinical psychologist in Berkeley, and we ran a study in my lab to figure out more about word a version. Now, what other reasons do we have for thinking that the sound of the word has anything to do with it. Well, first of all, it's not uncommon to hear things from people with word a version who point to a phonetic detail, in other words, how the word sounds like that they hate words that contain the sound oil or oiin. An example of this is the word ointment, which is despised almost as much as moist and the political writer William Safire pointed out that the oise sound triggers an aversion in some people, and he said he thinks this is why some people insist on being called an attorney instead of a lawyer, or other people hate the word shibbleth even if they don't know what it means. Or one guy online noted that he has word a version to any word beginning with cht, like Cathonic or Cathonian, and he doesn't like similar words like Cthulhu, which was a creature created by the sci fi writer Lovecraft in nineteen twenty eight. So many, many of the words that people find aversive seem unrelated to the meaning and more about the sound. So we focused in on the sound issues at play. What is the mapping between how something sounds and the emotion it triggers. So we tested two hundred and forty four people and what we did is we built three lists of words matched by the first letter and the length. The first list was aversive words based on the most commonly reported disliked words in online forums, so words like moist and tender and slacks and giggle and so on. And list number two was a list of other words generated from a word generator that matched in length or meaning or first letter. These were in different experiments, but these were all neutral words that nobody found versive. And the third list was nonsense words that had the same phoning frequency of English, but they were totally made up, like strains or yin's or pilp. So as an example, slacks might be the commonly reported aversive word, and then we tested against the word slopes which is neutral, and slent, which is a nonsense word meaning it's a word that's just made up. Or another example is moist and moose and ritz or a giggle and pickle, and gampin. So we asked participants to read words and record their feelings about the sound of the words. So you see a word presented on the screen from any of these categories, and with each word you rate it on a scale from most unpleasant to most pleasant. So what did we find. The average rating for the aversive word group was significantly more unpleasant than the real word controls. So we know that a subset of the population has greater than average version of these words, but what we had was a random population sample. But even here we find that the pre selected aversive words are more unpleasant on average than the matched control words. So that suggests that there may be something different about these aversive words like moist and slacks, and that causes these words to be more commonly disliked. But we also found something unexpected, which was that the most unpleasant words for people were the nonsense words. In other words, to our surprise, the nonsense words like gloike and frajoians and ulvasus and pesmeri and nullogh were even more aversive than the words that we intended to be aversive. So what does that mean? Well, we started to examine why we got that result, what is it about the aversive words and the nonsense words that's getting to some people? It presumably has something to do with the particular phonemes, the sounds and the words, but what well. One idea that people have suggested is that particular phonemes may inherently connote a pleasant or unpleasant valance. For example, there was an eighteenth century Russian poet named Mikhail Lemonzov who asserted that tender or positive or pleasant subjects should be described using vowels like I and e, and that unpleasant, fear evoking subjects should be described using vowels like oh and ah. But this isn't generally the same from language to language, or even from person to person. And so we started to consider the possibility that perhaps certain sounds go with certain emotions because those sounds occur with different frequencies in a given language. So why would it matter if some sound is more likely to occur than another. Well, in psychology, there's a phenomenon known as the mere exposure effect, in which people tend to prefer familiar items or concepts over unfamiliar ones. This is so important that I'm gonna take a minute to talk about this. The mere exposure of is also known as the familiarity principle, and it points to the fact that people develop a preference or a liking for things that they are exposed to repeatedly, even if they were neutral to it at the beginning. The more you encounter something, the more you tend to like it, and this is true, by the way, whether or not you consciously remember encountering it before. This has been shown in a million studies. From the people we meet to the products we encounter, familiarity breeds preference. For example, you might find yourself gravitating towards a particular song on the radio after you hear it a few times, or you might feel more comfortable with someone that you've met a few times, even if you didn't feel a strong initial connection. The mere exposure effect highlights the brain's inclination to find comfort in the familiar. Now. Possibly this is because repeated exposure reduces the uncertainty or the perceived threat associated with anything unfamiliar, so over time, this increased comfort results in a preference or a liking. And by the way, the way that you study this in the lab is you show people shapes or faces or words that they haven't seen before, and you have them rate them, and what you find is that they tend to rate these things more positively after being exposed to them multiple times, even if they're not consciously aware of the exposures. And this mere exposure effect is leveraged all the time by marketers and advertisers who use repetition to make products more appealing. This is why companies will pay a lot of money to have their product appear in the background of a television show or a movie, because that way we feel closer to it. We warm up to things that we encounter frequently. Now, this is issue of familiarity. It also applies in the realm of language. If you're exposed more to certain sounds, you come to prefer those over infrequent ones. So we explored whether this familiarity effect holds true at the level of sounds to explain word a version, so we calculated the probability of certain sounds going together in the English language. Essentially, if you look at a word, how word like or well formed it is. So, for example, take the word blick. It doesn't violate any sound constraints in English. But if you have the word benick that's less permissible because of the initial b n sound. So essentially, the less a word sounds like other English words, the lower its probability is. If you want to know, this is called phonotactic probability. And by the way, if you want to read all the details of the study, I'm linking our paper at eagleman dot com slash podcast. So what we found is that the phonotactic probability how likely different sounds go together. This mapped right onto what we found for the scores. The nonsense words, which everyone hated, had the lowest probability of existing as words. They were the least word like in the sense of all these sounds ending up together. Now, the aversive words like moist and slacks and nugget had higher probabilities of those sounds going together, but these were less probable than the control words, the words that nobody minded. So the control words had the highest probability of the sounds going together. So sound groupings that were improbable mapped onto higher aversion. And then we looked at a related measure. You can calculate what's called the neighborhood density for any word. This just tells you how many words differ from your word by only one phoneme. So for instance, cat has many neighbors like sad or bad or bat or can or cow and so on. Or neighbors of the word urge are earth and earl and edge and urn and age. You just change one sound in the word and you're at some other new word. So some words have lots of neighbors, but others don't. And so neighborhood density measures how similar sounding a word is to other words, and we find the same result here. The nonsense words, on average, had the fewest neighbors. They had the fewest words that sounded like them, and people hated these the most. Then you had the aversive words like moist, and they had some more neighbors to them. And finally, the control words had the most neighbors. So if you're a word with fewer other words that sound like you, you are more unfamiliar. And again this suggests that unfamiliarity plays a key part in the experience of aversion. So words with improbable combinations of sounds that sounded less like other English words, these were more likely to be unpleasant. Unfamiliarity correlates with aversion. Now just to wrap this study. I suspect that linguistic familiarity, like we explored here, is just one important piece of the word aversion puzzle, because there's a lot of variability in the data that's not explained fully by familiarity. For a full explanation, we'd almost certainly have to include the meaning of the word as well as something about an individual's prior experience of that particular word. So there's still plenty to do in terms of understanding who has this and who doesn't, and surveying speakers in other languages beyond English to understand about their word a versions. Just as an example, one Spanish speaker I saw said she has a horrible aversion to words like socopar, which means to cover up. She can't stand the word. So we can find these same principles across languages, and we need to understand what that tells us. And I think there are other questions too, like is it only negative emotions? Maybe certain words trigger really positive emotions, but maybe for some reason that doesn't get talked about as much. And finally, my lab and others have been searching for the genes that underpins synesthesia and the signatures in the brain of this crosstalk. The question is what do these look like for word aversion? But what we can already see is that in some people, certain sounds trigger emotions, and this seems to be another form of synesthesia, where there's a blending between regions of the brain that are normally a little more separate. Now, as I noted at the beginning, only some fraction of the population experiences word aversion, and it's hard to estimate that percentage until you do a careful population study, let's say, testing ten thousand people about it. But I want to flag something important here, which is that doing a population study, say on the internet, isn't totally straightforward, and it has to be done carefully because people often confuse word aversion for whatever their own pet peeves are, like what we discussed earlier, what words they find overused or used mistakenly, or a word that's elitist or patronizing or whatever. Now, why might people confuse these things with word aversion, Because, as I've discussed throughout the Inner Cosmos podcast, it's often really hard to imagine what it is like to be in someone else's head. And if you don't know that experience can be different for different people. It's easy to mistakenly believe that everyone must be having the same experience that you're having on the inside, and so we interpret new information by shoving it into our own model of the world, even when it doesn't quite fit. In other words, someone tells you that they feel a certain way, and you say, I know exactly how you feel. Well, you may or may not. You can only interpret their story through the lens of your own experience. So when the study of word aversion first began, it took a lot of effort to convince people who didn't have word a version that this was a thing. Why because they were interpreting the claim through only a single perspective on the world. As an example, there was a British guy I saw online who didn't experience word a version, and so he asserted that this was quote an American thing that didn't exist in British English. Well, we now know he's incorrect about that. Many Brits have this, but he's making the common but fundamental error of assuming that because he doesn't experience it, British people in general do not. And I stumbled on several comments about this online, especially when this all started a decade ago, where people would say things like word a version is a quote rare and weird neurotic behavior that's being talked about by point one percent of women. Because we know these aren't the numbers. This is another example of our naive internal models, where we tend to assume that if if we don't experience something, it's because it doesn't exist and other people are just making it up. It's just like I talked about in other episodes about synesthesia or how we visualize things, like some people imagine a scene like a movie and others have no particular image at all in their heads. Or take mental illness. For millennia, the approach to mental illness was to say, just toughen up, or in other cases it was we can torture you until you start acting normally. It took literally thousands of years before people started to realize that the experience in one person's head can be different than the experience in their own and what happened through history happens in the course of our own lifetime too. A large part of your passage into maturity is realizing that people can be quite different on the inside and coming to override the assumption that every one is having an experience just like yours. So, to wrap up today's episode, reality is not one size fits all. Two people can listen to the same words, and for one it's aversive and for the other it's totally neutral. It's just like eating cilantro or the feel of wool against your skin. You can have two humans experiencing the same event and having very different experiences. The important lesson to keep in mind here is that if you are only trying to understand your own reality, you're like a fish in water trying to describe water. It's impossible to describe what water is because you've never seen anything other than that. But when you see a different way that things can be, that gives you a broader platform from which to build theories. And that's one of our deepest goals in neuroscience, to understand how the specific microscopic activity in your three many pounds of wet, gushy, alien computational material maps onto the world that you see and enjoy every day, How the unique activity in your head maps onto the view that you're looking at right now, the feel of your clothes on your skin, the sound of my voice in your ear because for each of us, reality is a little bit different. Go to Eagleman dot com slash podcast for more reading and more information. Send me an email at podcasts at eagleman dot com with questions or discussion, and I'll be making an episode soon in which i address those. Until next time, I'm David Eagleman, signing off from the Inner Cosmos assas

We all know people who hate the word moist, But why are they okay with synonyms like damp or muggy or wet. What's going on in their brains and what does this have to do with shapes or autism or synesthesia. Welcome to another episode of Inner Cosmos with me David Eagleman, all about the magical three pounds of matter that constitute your reality. In today's episode, we're going to talk about a wild and relatively new example of the differences between people's internal cosmoses. We're going to talk about word aversion. Imagine that you find a tribe of people with little contact with the outside world, and they show you that they have some shapes that they draw. One of them is a round, blobby object, and another shape is a sharp, spiky star pattern. Now you figure out that one of these they call bouba and the other they call kiki. And the question I have for you is which do you think is which is the blobby thing called kiki and the starburst thing is called buba? Or would you guess it's the other way around? If you are like essentially everyone else on the planet, you guessed that the blobby object was called buba, and the sharp object was called kiki. Now, the buba kiki effect was something studied in a psychology paper a century ago, and it was a little surprising because essentially everybody gives the same answer, linking the soft sounding word with the soft looking object and vice versa. But this is surprising because in general, there's really not supposed to be a relationship between the sound of a word and what it looks like. But what this tells us is that we sometimes have relationships across the senses. And if you heard my episode on synesthesia, episode four, you'll know that a fraction of people, probably between five and ten percent, have this kind of blending of the senses in more unusual ways. For example, they might see letters and that triggers a color experience for them, where they might hear something, and that triggers a visual shape for them where they might taste something and that puts a feeling on their fingertips and so on. Now, I'm going to come back to this issue of synesthesia. That want to return to the issue of the sound of a word. So let me begin by pointing out that in general, the sound of a word has no relationship to its meaning. You can call a car an automobile or a vehicle or whatever. We don't just call it a room. So the sound that we make with our mouth car is usually quite arbitrary, and you can see this by comparing across languages, where you can call it a mahonite or che or vatur or whatever. So the sound of a word and its meaning are typically unconnected. But it's not always so simple, because sometimes we do find a strange relationship between sound and meaning. Think of on amotopeia, where a word imitates phonetically, in other words, in sound what it describes. For example, for a gun firing we say bang. It's a mapping between the sound and the meaning that's not arbitrary. Or describing the sound a fly makes as buzz, or describing the sound of cat makes as hiss, And there are lots of examples of onomatopeia, like the sound of something breaking we say crash, or the sound of something plunking into the water, or the sound of a clock we use TikTok, or when we think about the sound of cat makes in English, we say meow, or for a dog woof or a frog ribbit. These are all examples of words that have a phonetic relationship with the thing they describe. In other words, they sound like it. And sometimes these relationships between sound and meaning are even more subtle. There's something called phonus themes, which are clusters of sound that you find in common across related words in a language. So in English we find the sound made by gl or ghul is associated with light or shining. Think about words like gleam, glitter, glisten, glow, and more loosely, words like glorious or glamorous. Across all these words, which are cousins in meaning, you find the same sound. So linguists are aware that sometimes there are mappings between the way a word sounds and its meaning, but there's not much known about the more specific relationship between word sounds and an unusual emotional response that can be triggered. So I got interested in this question because something didn't escape my notice and probably not yours either, And that's the fact that some fraction of my friends can stand certain words. This is something that struck the author George Saunders when he was giving a reading of a new book he'd just published, and he was surprised that people in the audience didn't really seem to mind his really rough language with the cussing and the sex scenes and so on. But two people told him that they really hated that he used the word moist. His cousin who was there, said it made her feel a little physically ill when he used it. And then he gave a reading in a different location, and his sister was there and she said the same thing. Her reaction wasn't to the risk a language and scenes, but to a single word moist. Now, as it turns out, lots of people, people you know or people you love, they hate the word moist. It triggers a feeling of aversion or disgust. For some people, this makes cooking shows unwatchable, or they can't read an article about forestry and soil or whatever. Moist is famous for being a word that many people despise, but moist is just one word of many consider the word tender, the word slacks, the word tissue. Now, many of you listening don't mind these words at all, and others are disgusted by these or consider words like the yellow thing inside an egg, the word yoke. Some people hate that word and many other words come up in our studies as being unusually hated words like nourish, bulge, pulp, giggle, fluffy nugget, or there was a guy who got interested in astronomy but got put off by the term globular cluster. So this phenomenon is called word aversion, and what it involves are words that are neutral in their meaning, like tissue or a globular cluster or whatever. There's no particular emotional meaning to the word, but it triggers a feeling of repugnance in some fraction of the population. My colleague Mark Lieberman, who's a linguist at the University of Pennsylvania, he set out to give a clear definition of word aversion. He said, it's quote a feeling of intense, irrational distaste for the sounder sight of a particular word or phrase, not because its use is regarded as etymologically wrong or logically wrong or grammatically wrong, nor because it's felt to be overused or redundant or trendy or non standard, but simply because the word itself somehow feels unpleasant or even disgusting. End quote. So I want to be clear that there are all kinds of words that you can hate for other reasons. You might find some word snobbish or foolish, or you might think that it's being used incorrectly. But those are all different from word aversion, and we're not talking about politically charged words like words that are sexually taboo or religiously taboo, or ethnic slurs or other offensive words. Word aversion is a different thing. And Lieberman points out that while people say they hate words like moist, it's not the angry kind of hate. It's more the cringe, shudder, shiver, gives me the willies kind of hate. As an example, one person online said, and I quote the word panties grosses me out, and hypercorrect usage of whom annoys me. But the feelings I get when I hear them are two distinct sensations that I would never confuse end quote. So the scientific mindset cares about this distinction and understanding what is going on here, And my lab got interested in this because we saw that word aversion provided an inroad to study this strange and unexpected relationship between sound and emotion. Now, before we dig in on this, I want to fully flesh out word a version with some examples. And there's a ton of information about word a version spread all around online forums. So I'll just give you some examples to enhance our intuitions about this. One woman named Lisa posted quote, there's one word that I hate above all others. If I come across it, I must immediately declare my hatred of it to anyone who is there to listen. If there's no one around, I'll resort to primal arguing and hit the page where the word resides. The word is hard scrabble. I don't have a logical reason for hate this word. I haven't had a traumatic experience with it in the past. I simply find it revolting. It's ugly. End quote. Someone else posted luggage. Can't stand that word luggage. It just feels gross. End quote. Someone else says I hate the word pugilist. Another says tissue shiver. It gives me the willies. Someone else writes, my girlfriend's sister hates the word moist fist used together. So if you start looking around, you'll find literally thousands of posts and discussions about this, which, from a scientific point of view, suggests that there's something to be understood here. Now. Quite commonly, when you look through these forums, you see words like moist and fleshy, and panties, but there are lots of other words that are less expected. One woman reports, quote, my mother hated gut, would not let us say it, as if it were the worst word in English. End quote. Other people online give examples like goose, pimple, or a chunk or wedge, or meal or baffle or squab or cornucopia. One person pointed to the word giggle and said he hates that word quote with the concentrated hatred of a thousand hate filled sons. End quote, fudge conduit. One person said his aversive words were a gig motif and whimsy. He says, quote no rational reason, just hate them unquote. Now there are a few important clues that we need to note here. The first thing is that not everyone experiences word aversion. In fact, most people don't, and this is something I'll come back to in a bit. But of course it's hard to know what fraction of the population has this. So about a decade ago, Mark Lieberman decided to take a cre creative shot at gathering some data. He noted that the problem with scraping people's online postings about word a version was that it can't tell you what fraction of people experience it. In other words, how many people have word a version? Because if a commenter writes how aversive moist is to them, you don't know if that poster represents one out of five people or one out of five hundred. So Lieberman had an interesting idea to look at famous authors and see how often they use the word moist. Now, just a side note that this is the kind of experiment that you can do now, but you couldn't do this twenty five years ago because you need to analyze every word of the entire corpus of each author, everything they've ever written. Nowadays this seems trivial, but I just want to point out that this kind of questioning and answering was just not available even a generation ago. So we're living in terrific times, Okay. So he tapped into projects Gutenberg, which was an early project to digitize books and make them searchable, and using that approach, which was still a little rough back in twenty twelve. When he did this, he analyzed the complete works of fifty authors. So this was about one hundred and twenty five million words, with an average of about two and a half million words per author, and he found that on average, there were about six appearances of the word moist per million words. Now here's the interesting part. He found that for some authors, like Jane Austen, for instance, there was never a single mention ever of the word moist. If it was just a random draw, the fact that she never ever used moist would have a probability of happening by chance of zero point seven, in other words, a very low probability of that happening just by chance. On the other hand, some authors use it plenty. The short story writer Brett Hart from the eighteen hundreds used fifty six moists, or about twenty two times for every million words. But compare rehtt Hart to Mark Twain, who lived at almost exactly the same time. Mark Twain only used the word moist two times in his entire career, and he wrote a lot more so. Mark Twain used only zero point five moists per million words, or forty four times less often than Brett Hart. And by the way, Lieberman points out that one of Twain's uses of the word moist hardly counts because it was part of a long made up name of an elephant, and the other use of moist Lieberman asks with a question mark whether that single use of the word might have been in by an editor. In any case, this kind of literary detective work reveals that some authors are happy to use the word and others avoided completely in every sentence they've ever published in their entire career. Now you might point out that maybe these authors just wrote about different topics and so moistness just didn't come up. So to address that, Lieberman quantified other humidity related words like wet, damp, or dry or arid, and he did the calculations on those, and he found that Mark Twain used plenty of such words, He had about half the rate of Brett Hart, even while his use of the particular word moist was forty four times less frequent. So by looking at someone's entire corpus of writing, you might be able to tell something about who hated moist and who didn't care. Now, why is there any difference between people? Well, let's take a quick dive version into another area that my lab is studied for a long time, sinesthesia. These reports of word aversion immediately grabbed my attention because in sinesthesia, as I mentioned at the beginning, we see a cross blending of the senses. So sounds of certain words might trigger a color experience, or a texture or a taste, and word aversion sounds quite a bit like that. We're talking about sensory experiences that we usually consider as separate and distinct, but in some people the lines between these different sensations aren't so rigid. And so although we typically think of synesthesia as triggering colors or sounds, there certainly seem to be examples where any emotion is triggered, and often it's an emotion of aversion or disgust. So something I've previously suggested in the literature is that the sensory processing disorder that we see in autism is actually a kind of synesthesia. Sensory processing disorder is when you see a kid who can't stand certain sounds it drives them nuts, like the sound of a vacuum or the sound of a zipper or somebody chewing or so on. So I think that is a form of synesthesia, But instead of a region of the brain like color getting triggered, it's regions involved in aversion. There are a whole bunch of circuits in the brain involved in pain and disgust or itch or whatever. So if sensory processing disorder is a form of synesthesia, you can see why word a version grabbed my attention. I wondered if there might be some sinesthetic relationship here, that a person might get this cross blending of different senses with the sound of the word and an emotion that that triggers. Instead of colors, one gets a feeling instead of indigo blue, one gets the creeps. So I got very interested in understanding what was going on here, And the first thing I zoomed in on was that for people with word aversion, it doesn't happen for all words, just certain words. So how could we drill down on that? First I found in the literature that there had been a study on word aversion. A researcher named Paul Thibodeau explored what he called moist aversion, and it was binary, in other words, just based on your yes or no answer to the question would you characterize yourself as being particularly averse to the word moist. But we know that word a version is much broader than moist aversion. Many other words appear all the time in self reports of word aversion, like tender or slax or nugget or tissue. So Thibodeau's study was an important first step in understanding word of version, but it left a lot unanswered. Okay, so what were the next steps for us? If aversive words were only words like moist, we might think it's some reference to the meaning of the word. But something I noticed is that people often clarified that they were fine with alternative words or synonyms. Even if they hated the word panties. They were fine with words like undies and thong, just not panties. And even if they hated the word moist, they were fine using synonyms in its place, like damp or humid, or muggy or wet. So that suggests it's not just about the meaning, but perhaps there was something else going on. And with so many of the other words that show up on these lists, it's essentially impossible to think of any meaning, even several degrees away that could possibly be triggering. Who has anything against the word giggle or wedge or luggage. So one possibility that suggested itself is that it's the sound of the word, not just the meaning, that was the basis for the aversion. And so we got interested in this question, and I started looking into this with a student of mine, Hannah Bosley, who's now a clinical psychologist in Berkeley, and we ran a study in my lab to figure out more about word a version. Now, what other reasons do we have for thinking that the sound of the word has anything to do with it. Well, first of all, it's not uncommon to hear things from people with word a version who point to a phonetic detail, in other words, how the word sounds like that they hate words that contain the sound oil or oiin. An example of this is the word ointment, which is despised almost as much as moist and the political writer William Safire pointed out that the oise sound triggers an aversion in some people, and he said he thinks this is why some people insist on being called an attorney instead of a lawyer, or other people hate the word shibbleth even if they don't know what it means. Or one guy online noted that he has word a version to any word beginning with cht, like Cathonic or Cathonian, and he doesn't like similar words like Cthulhu, which was a creature created by the sci fi writer Lovecraft in nineteen twenty eight. So many, many of the words that people find aversive seem unrelated to the meaning and more about the sound. So we focused in on the sound issues at play. What is the mapping between how something sounds and the emotion it triggers. So we tested two hundred and forty four people and what we did is we built three lists of words matched by the first letter and the length. The first list was aversive words based on the most commonly reported disliked words in online forums, so words like moist and tender and slacks and giggle and so on. And list number two was a list of other words generated from a word generator that matched in length or meaning or first letter. These were in different experiments, but these were all neutral words that nobody found versive. And the third list was nonsense words that had the same phoning frequency of English, but they were totally made up, like strains or yin's or pilp. So as an example, slacks might be the commonly reported aversive word, and then we tested against the word slopes which is neutral, and slent, which is a nonsense word meaning it's a word that's just made up. Or another example is moist and moose and ritz or a giggle and pickle, and gampin. So we asked participants to read words and record their feelings about the sound of the words. So you see a word presented on the screen from any of these categories, and with each word you rate it on a scale from most unpleasant to most pleasant. So what did we find. The average rating for the aversive word group was significantly more unpleasant than the real word controls. So we know that a subset of the population has greater than average version of these words, but what we had was a random population sample. But even here we find that the pre selected aversive words are more unpleasant on average than the matched control words. So that suggests that there may be something different about these aversive words like moist and slacks, and that causes these words to be more commonly disliked. But we also found something unexpected, which was that the most unpleasant words for people were the nonsense words. In other words, to our surprise, the nonsense words like gloike and frajoians and ulvasus and pesmeri and nullogh were even more aversive than the words that we intended to be aversive. So what does that mean? Well, we started to examine why we got that result, what is it about the aversive words and the nonsense words that's getting to some people? It presumably has something to do with the particular phonemes, the sounds and the words, but what well. One idea that people have suggested is that particular phonemes may inherently connote a pleasant or unpleasant valance. For example, there was an eighteenth century Russian poet named Mikhail Lemonzov who asserted that tender or positive or pleasant subjects should be described using vowels like I and e, and that unpleasant, fear evoking subjects should be described using vowels like oh and ah. But this isn't generally the same from language to language, or even from person to person. And so we started to consider the possibility that perhaps certain sounds go with certain emotions because those sounds occur with different frequencies in a given language. So why would it matter if some sound is more likely to occur than another. Well, in psychology, there's a phenomenon known as the mere exposure effect, in which people tend to prefer familiar items or concepts over unfamiliar ones. This is so important that I'm gonna take a minute to talk about this. The mere exposure of is also known as the familiarity principle, and it points to the fact that people develop a preference or a liking for things that they are exposed to repeatedly, even if they were neutral to it at the beginning. The more you encounter something, the more you tend to like it, and this is true, by the way, whether or not you consciously remember encountering it before. This has been shown in a million studies. From the people we meet to the products we encounter, familiarity breeds preference. For example, you might find yourself gravitating towards a particular song on the radio after you hear it a few times, or you might feel more comfortable with someone that you've met a few times, even if you didn't feel a strong initial connection. The mere exposure effect highlights the brain's inclination to find comfort in the familiar. Now. Possibly this is because repeated exposure reduces the uncertainty or the perceived threat associated with anything unfamiliar, so over time, this increased comfort results in a preference or a liking. And by the way, the way that you study this in the lab is you show people shapes or faces or words that they haven't seen before, and you have them rate them, and what you find is that they tend to rate these things more positively after being exposed to them multiple times, even if they're not consciously aware of the exposures. And this mere exposure effect is leveraged all the time by marketers and advertisers who use repetition to make products more appealing. This is why companies will pay a lot of money to have their product appear in the background of a television show or a movie, because that way we feel closer to it. We warm up to things that we encounter frequently. Now, this is issue of familiarity. It also applies in the realm of language. If you're exposed more to certain sounds, you come to prefer those over infrequent ones. So we explored whether this familiarity effect holds true at the level of sounds to explain word a version, so we calculated the probability of certain sounds going together in the English language. Essentially, if you look at a word, how word like or well formed it is. So, for example, take the word blick. It doesn't violate any sound constraints in English. But if you have the word benick that's less permissible because of the initial b n sound. So essentially, the less a word sounds like other English words, the lower its probability is. If you want to know, this is called phonotactic probability. And by the way, if you want to read all the details of the study, I'm linking our paper at eagleman dot com slash podcast. So what we found is that the phonotactic probability how likely different sounds go together. This mapped right onto what we found for the scores. The nonsense words, which everyone hated, had the lowest probability of existing as words. They were the least word like in the sense of all these sounds ending up together. Now, the aversive words like moist and slacks and nugget had higher probabilities of those sounds going together, but these were less probable than the control words, the words that nobody minded. So the control words had the highest probability of the sounds going together. So sound groupings that were improbable mapped onto higher aversion. And then we looked at a related measure. You can calculate what's called the neighborhood density for any word. This just tells you how many words differ from your word by only one phoneme. So for instance, cat has many neighbors like sad or bad or bat or can or cow and so on. Or neighbors of the word urge are earth and earl and edge and urn and age. You just change one sound in the word and you're at some other new word. So some words have lots of neighbors, but others don't. And so neighborhood density measures how similar sounding a word is to other words, and we find the same result here. The nonsense words, on average, had the fewest neighbors. They had the fewest words that sounded like them, and people hated these the most. Then you had the aversive words like moist, and they had some more neighbors to them. And finally, the control words had the most neighbors. So if you're a word with fewer other words that sound like you, you are more unfamiliar. And again this suggests that unfamiliarity plays a key part in the experience of aversion. So words with improbable combinations of sounds that sounded less like other English words, these were more likely to be unpleasant. Unfamiliarity correlates with aversion. Now just to wrap this study. I suspect that linguistic familiarity, like we explored here, is just one important piece of the word aversion puzzle, because there's a lot of variability in the data that's not explained fully by familiarity. For a full explanation, we'd almost certainly have to include the meaning of the word as well as something about an individual's prior experience of that particular word. So there's still plenty to do in terms of understanding who has this and who doesn't, and surveying speakers in other languages beyond English to understand about their word a versions. Just as an example, one Spanish speaker I saw said she has a horrible aversion to words like socopar, which means to cover up. She can't stand the word. So we can find these same principles across languages, and we need to understand what that tells us. And I think there are other questions too, like is it only negative emotions? Maybe certain words trigger really positive emotions, but maybe for some reason that doesn't get talked about as much. And finally, my lab and others have been searching for the genes that underpins synesthesia and the signatures in the brain of this crosstalk. The question is what do these look like for word aversion? But what we can already see is that in some people, certain sounds trigger emotions, and this seems to be another form of synesthesia, where there's a blending between regions of the brain that are normally a little more separate. Now, as I noted at the beginning, only some fraction of the population experiences word aversion, and it's hard to estimate that percentage until you do a careful population study, let's say, testing ten thousand people about it. But I want to flag something important here, which is that doing a population study, say on the internet, isn't totally straightforward, and it has to be done carefully because people often confuse word aversion for whatever their own pet peeves are, like what we discussed earlier, what words they find overused or used mistakenly, or a word that's elitist or patronizing or whatever. Now, why might people confuse these things with word aversion, Because, as I've discussed throughout the Inner Cosmos podcast, it's often really hard to imagine what it is like to be in someone else's head. And if you don't know that experience can be different for different people. It's easy to mistakenly believe that everyone must be having the same experience that you're having on the inside, and so we interpret new information by shoving it into our own model of the world, even when it doesn't quite fit. In other words, someone tells you that they feel a certain way, and you say, I know exactly how you feel. Well, you may or may not. You can only interpret their story through the lens of your own experience. So when the study of word aversion first began, it took a lot of effort to convince people who didn't have word a version that this was a thing. Why because they were interpreting the claim through only a single perspective on the world. As an example, there was a British guy I saw online who didn't experience word a version, and so he asserted that this was quote an American thing that didn't exist in British English. Well, we now know he's incorrect about that. Many Brits have this, but he's making the common but fundamental error of assuming that because he doesn't experience it, British people in general do not. And I stumbled on several comments about this online, especially when this all started a decade ago, where people would say things like word a version is a quote rare and weird neurotic behavior that's being talked about by point one percent of women. Because we know these aren't the numbers. This is another example of our naive internal models, where we tend to assume that if if we don't experience something, it's because it doesn't exist and other people are just making it up. It's just like I talked about in other episodes about synesthesia or how we visualize things, like some people imagine a scene like a movie and others have no particular image at all in their heads. Or take mental illness. For millennia, the approach to mental illness was to say, just toughen up, or in other cases it was we can torture you until you start acting normally. It took literally thousands of years before people started to realize that the experience in one person's head can be different than the experience in their own and what happened through history happens in the course of our own lifetime too. A large part of your passage into maturity is realizing that people can be quite different on the inside and coming to override the assumption that every one is having an experience just like yours. So, to wrap up today's episode, reality is not one size fits all. Two people can listen to the same words, and for one it's aversive and for the other it's totally neutral. It's just like eating cilantro or the feel of wool against your skin. You can have two humans experiencing the same event and having very different experiences. The important lesson to keep in mind here is that if you are only trying to understand your own reality, you're like a fish in water trying to describe water. It's impossible to describe what water is because you've never seen anything other than that. But when you see a different way that things can be, that gives you a broader platform from which to build theories. And that's one of our deepest goals in neuroscience, to understand how the specific microscopic activity in your three many pounds of wet, gushy, alien computational material maps onto the world that you see and enjoy every day, How the unique activity in your head maps onto the view that you're looking at right now, the feel of your clothes on your skin, the sound of my voice in your ear because for each of us, reality is a little bit different. Go to Eagleman dot com slash podcast for more reading and more information. Send me an email at podcasts at eagleman dot com with questions or discussion, and I'll be making an episode soon in which i address those. Until next time, I'm David Eagleman, signing off from the Inner Cosmos assas