The Philosophy of Smell

Josh Landy
What’s unique about our sense of smell?

Ray Briggs
Can it tell us things our other senses are silent about?

Josh Landy
How can we get better at navigating the world of scent?

Ray Briggs
This is Philosophy Talk, the program that questions everything…

Josh Landy
…except your intelligence. I’m Josh Landy.

Ray Briggs
And I’m Ray Briggs. We’re coming to you from the Stanford Humanities Center.

Josh Landy
Continuing conversations that begin at the Philosophers Corner on the Stanford campus, where Ray teaches philosophy, and I direct the Philosophy and Literature Initiative.

Ray Briggs
We’re very grateful to the Symbolic Systems Program for sponsoring today’s event.

Josh Landy
Welcome, everybody, to Philosophy Talk.

Ray Briggs
Today, we’re thinking about the philosophy of smell.

Josh Landy
You know, Ray, philosophers talk a lot about seeing things and hearing things. Why don’t we ever talk about smelling things?

Ray Briggs
Well, you know, some of them have and they found that smell is kind of weird. So when you see something, it’s clear what you’re looking at—there’s a person or a chair or a room. When you smell something, what is it exactly that you’re smelling?

Josh Landy
I don’t get it. I mean, let’s say I’m smelling a delicious loaf of bread. I mean, aren’t I smelling a delicious loaf of bread?

Ray Briggs
Well, maybe. But what happens if you walk into a kitchen where somebody was baking bread an hour ago, but now the breads all gone? You’re still smelling something, but what?

Josh Landy
Alright, okay, that is a fun puzzle. But I don’t see that it’s that different from the other senses. Like let’s say, you know, I’m lying in a lovely grassy meadow at night skies clear. I’m looking at the stars, right? Well, I mean, a lot of what I’m looking at is long gone. So how is that any different? Like you’re smelling the lingering aroma of bread. I’m seeing the lingering trace of stars.

Ray Briggs
God, don’t be so dazzled by the stars, Josh. I mean, they’re an exception. Most of the time, what you see is just right there in front of you. Whereas, you know, the scent of flowers pops in on the breeze or this horrible odor emanates up from the subway—what you’re smelling is just puffs of air.

Josh Landy
Okay look, I’ll grant you that smell is different. But that just confirms my point. There needs to be a ton more philosophy of smell—like stuff smell can do for us that no amount of looking and listening can make up for.

Ray Briggs
I don’t think it’s that complicated. So when I look at a picture, for example, I can distinguish different parts of the picture. I can name colors and shapes. Or when I listen to a song I can pick out individual notes and chords even lyrics. But just try putting something like Chanel No.5 into any kind of words.

Josh Landy
No problem… Drama. Elegance. Boldness. You are the you.

Ray Briggs
Yeah, nice try, but it’s not going to help me pick it out of a lineup.

Josh Landy
Okay, maybe you won’t have you pick it out of a lineup. But the only reason for that is we don’t have the words for it. Most languages are totally biased against smell. We have a zillion and one words for a pretty face. We have like two for a nice fragrance.

Ray Briggs
Yeah, and that’s there’s a reason for that: we don’t need those words for smells. Our noses just aren’t that sophisticated. What goes on, we pick up on maybe a tiny fraction of it. And it’s not that important to your decision making. So when’s the last time you picked up a book because of the way it smelled?

Josh Landy
Okay, that’s fair. But look, I noticed, Ray, that you didn’t ask me about choosing a partner. I mean, when it comes to that kind of thing, many scientists would say there’s a lot going on in the realm of smell. And whatever we’re picking up on, we’re picking up on unconsciously. That’s why we don’t have the words for it.

Ray Briggs
Wait, you’re complaining that we don’t have the words for something that we’re not even conscious of? How is that supposed to work? In order to name something, I have to notice it consciously.

Josh Landy
Well, I don’t see the problem. I mean, look, take my favorite author, Marcel Proust. He had no problem writing about smells. And brilliantly, right. He said, “Even when the objects of our past are long gone, smell and taste still remain for a long time like souls. And on their own most improbable droplet, they can hold up the immense edifice of memory.” Isn’t that gorgeous?

Ray Briggs
It’s absolutely lovely. But it doesn’t tell me anything about the cookie he’s writing about, much less how it smells. I’m not gonna write a 3000 page novel every time I want to describe a pleasing aroma.

Josh Landy
Okay, but you don’t need to write a 3000 page novel—just use a teensy tiny little metaphor, right? I mean, that’s what wine buffs do. They’ll say a burgundy is serious and broad-minded, or a rosé is light-hearted and cheeky.

Ray Briggs
Wait, are you being cheeky? You’re not being serious? So just imagine it. Two people are arguing one of them says, “Oh, this rosé is very broad-minded,” and the other one says, “No, actually, it’s kind of narrow-minded.” How are they going to settle that? It’s all just kind of interpretation. There’s no fact of the matter.

Josh Landy
Well, I’m sure there are some facts about smell and even some philosophically interesting truths. And I’ll bet our guest will help us figure out exactly what they are. It’s Asifa Majid, an olfaction expert from the University of Oxford.

Ray Briggs
But it’s not just the philosophy of smell that’s cool. There’s also a lot of really fascinating olfactory art.

Josh Landy
So we sent our Roving Philosophica Reporter, Holly J. McDede, to have a sniff at some of it. She files this report.

Holly McDede
M. Daugherty is a scent artist and researcher. And people ask a lot of questions about that.

M. Dougherty
I keep getting asked if I’ve seen the movie “Perfume,” which is about a serial killer who’s capturing body odor. That’s one that comes up a lot, which is good fun.

Perfume
I don’t know what a formula is. But I can make Amour and Psyche for you now. And you think I just let you slop around in my laboratory with essential oils and with a fortune!

Holly McDede
But Daugherty’s intentions are good. They want to help people improve their olfactory literacy, our ability to read smells.

M. Dougherty
There’s so much information being communicated in smell from like health, to mood to history, cultures, all sorts of things like that. And I think we’re just not socialized to tune into it.

Holly McDede
Dougherty’s interest in smell really kicked off during a class at the Institute for Art and Olfaction in Los Angeles, where they looked at recreating the smell of Cleopatra’s perfume.

M. Dougherty
And while I was there, smelling a whole wall of materials, smelling things I hadn’t really paid attention to before, there was someone else that was recreating the smell of Hot Cheetos.

Hot Cheetos
Flamin’ Hot Cheetos, anyone?

Holly McDede
Daugherty was hooked. They created an odor odor—instead of playing a sound, it plays a smell.

M. Dougherty
You can really just play around with playing different keys releasing different smells, combining them together, you can make something like lemon. And then if you add a sweet note to it, it’ll smell more like candy then citrus.

Holly McDede
During the thick of the COVID pandemic Daugherty showed their work at a gallery called Olfactory Art Keller in New York. Because of COVID loss of smell was fresh in everyone’s mind. They wanted to offer something good through smell, so they pumped the scent of the forest out to the sidewalk and scattered scented objects throughout the gallery.

M. Dougherty
There’s like the fresh air right where it’s like air that’s so fresh, you can almost feel the cool when you’re inhaling it.

Holly McDede
A little bit of decay a little bit of funk—trees, animals… The work at Olfactory Art Keller can be political, too. Gayil Nalls is an internationally-known pioneer of olfactory art and science. She’s also disturbed by how synthetic fragrances are hurting the environment.

Gayil Nalls
Neurotoxins now are at every part of our environment. You know, they’re in the top of the Alps. They’re in the sludge where all young, aquatic life is’s born.

Holly McDede
Nalls’ exhibit at the gallery is a photographic series titled politics of perfume objects, the Avon sweet. She arranged and reconfigured Avon decanters to give them a new narrative. Avon is a huge cosmetics company and a decanter is a small plastic or class file that contains a fragrance.

Gayil Nalls
I began to explore how these chemicals ended up being so massively deployed into the United States in a short period of time, and I landed upon Avon and began to collect their older bottles and explore the iconography.

Holly McDede
In one piece, a bullet sits atop the Liberty Bell. In another Thomas Jefferson is dwarfed by his handgun.

Gayil Nalls
It’s just a bit crazy how this iconography was used to sell these untested chemicals and deploy them in mass tonnage throughout the country in no time.

Holly McDede
The exhibit also features a new scent: the smell of George Washington’s false teeth.

Gayil Nalls
It was kind of about his favorite meal, really—griddle cakes and honey and some other nice things that were soft, because he had a lot of teeth problems.

Holly McDede
This all might sound bizarre, but it shouldn’t—we’re talking about the facts of life. George Washington had false teeth; smell is all around us. Olfactory Art Keller aims to make the world of smell based art more accessible. Andreas Keller is its owner and operator.

Andreas Keller
There’s a big need. There’s like a large group of creative interested in working with smell. But they have no infrastructure, they have no outlet, they have not enough knowledge to do that. And so I kind of felt that there’s a need for doing that.

Holly McDede
As one of his visions…

Andreas Keller
I would hope in the future to also have short movies that are scented.

Holly McDede
That way people can see feel and be in smell. For Philosophy Talk, I’m Holly J. McDede.

Josh Landy
Thanks for that great report, Holly, which definitely passes the smell test. I’m Josh Landy, along with my Stanford colleague Ray Briggs and we’re with a live audience at the Stanford Humanities Center for an episode generously sponsored by the Symbolic Systems Program.

Ray Briggs
Our guest today is an experimental psychologist from the University of Oxford and an olfactory expert. Please welcome to the Philosophy Talk stage Asifa Majid.

Josh Landy
So Asifa, you’re an expert in all kinds of things mind-related, but how did you get interested, particularly in smell?

Asifa Majid
I think, for me, the interest is really in language. And as we’ve talked about already, smell seems to be something that’s difficult for people to talk about. So that’s what brought me into it. I was like, everybody in this room, probably not particularly oriented towards smile, didn’t really notice it. But now that it’s been brought to my attention, every room, every person is a new, interesting object to experience not just through vision, but through the sense of smell, too.

Ray Briggs
So Asifa, we have so many words for like things we can see, but so few for what we can smell. Why is that

Asifa Majid
in English, you mean. So this seems to be something that’s a limitation of English and other related languages in Europe. But if we look at the global diversity of languages in the world, there’s around 7000 languages that are spoken today, we find everywhere really, pretty much nearly every part of the world has a language that has a developed smell lexicon, so lots of different words to describe lots of different qualities of smells.

Ray Briggs
So why is English so impoverished then?

Asifa Majid
Yeah, that’s a great question, what is going on with those, there’s different ideas about what might have happened. So one speculation is that we weren’t really smell oriented until the industrial revolution. So when we were living, a more farming lifestyle, closer to nature, we were paying attention to our sense of smell. And then as people started moving to the cities, and then producing vast amounts of sewage, which they then polluted rivers with, there is a need for a new hygiene practice. So we started clearing things up sterilizing them, but also getting rid of smells. So we now live in an urban environment where maybe there isn’t the same diversity of smells, because we are getting rid of them everywhere that we can, and maybe replacing them with a few synthetic odors that are carefully curated. So that that might be one reason that we’ve cultivated an environment that doesn’t do it.

Josh Landy
So that sounds like a kind of time based explanation for the variation of presumed there’s also space based once like, right, so you’ve written about how maybe there’s some correlation between these languages that have larger vocabularies for smell. And, for example, hunter gatherer populations, or, you know, if you’re in a rainforest, which is an area that that’s really rich in smell, and not that great on sightlines that might lend itself to a language that’s rich in smell, what are those core legs, they they hold up?

Asifa Majid
There’s certainly—it’s another great potential explanation. So in a tropical rainforest, you’ve got much more biodiversity, there’s just more plants and animals that can potentially emit odors, and you have high humidity. So humidity helps us smell. Whereas most European languages have evolved in a temperate climate. So perhaps there’s just not the same number of smells. But we do find smell lexicons in places where there’s desert and coastal areas. So still not clear, but certainly something we’re lacking.

Ray Briggs
This is Philosophy Talk coming to you from the Stanford Humanities Center. Our guest is Asifa Majid from the University of Oxford.

Josh Landy
How would you describe your favorite smell? Why is it so hard to express what makes it unique? Do we need a better smellexicon?

Ray Briggs
Noses, roses, and descriptive proses—along with comments from our live audience, when Philosophy Talk continues.

Sparks
That’s why I wanna spend my life with you, that’s why I wanna spend my life with you

Josh Landy
Welcome back, I’m Josh Landy. And this is Philosophy Talk the program that questions everything…

Ray Briggs
…except your intelligence. I’m Ray Briggs, and our guest is Asifa Majid from the University of Oxford. Today we’re thinking about the philosophy of smell. Special thanks to the Stanford Symbolic Systems Program for sponsoring today’s episode.

Josh Landy
Do you have a sweet question or a stinker of a comment? Join the discussion by raising your hand and Jaime here will put you on the list and bring the mic around to you when it’s your turn.

Ray Briggs
So Asifa, what’s distinctive about smell as a sense?

Asifa Majid
Well, you picked out some things that are distinctive already. Maybe in contrast, to vision, smell is ephemeral. But then so is sound. So that doesn’t seem to be so particular. I mean, so smell is a chemical sense, unlike what we get through the eyes, where we’re getting wave lens, in for a sense of smell molecules in the air, every time we breathe in, we’re taking in a sample of the molecules in the air, and some of them get through our mucous to the olfactory neurons, and then we can smell them. So it’s different logic in terms of the infrastructure that’s needed just to perceive something. But there are kind of some things that come from that. So I’m only sampling the air when I breathe in, when I breathe out. There’s nothing so it’d be like every time you breathe out, you close your eyes and didn’t see the world for that moment. What would that reality be like? So there’s a sampling of the air successively over time that you have to keep in mind. That’s something that’s a bit distinctive.

Josh Landy
So that raises interesting questions for philosophers, because, you know, philosophy hasn’t necessarily been that great in relation to smell, because a philosopher Peter Strawson, said something like, you know, you don’t lose your sense of what the world is, if you have a cold. He turned up his nose, the sense of smell, and I think, okay, so how should we let our understanding of smell change the way we think about perception? Like, should we be thinking about the senses, as sort of on a par instead of thinking, well smells just trying to do what vision is doing, but worse? Could we be thinking about these different senses is kind of complimentary that they have maybe limitations, but they also have different affordances. And there are things that you can do by smelling that you just can’t do with any of the other senses, that seems about right.

Asifa Majid
Are you seeing that losing the sense of smell wouldn’t really affect us. But, you know, for many people who’ve had COVID and lost their sense of smell, they also lose their enjoyment of food, it’s not the same anymore. And we know that people that lose their sense of smell, who have anosmia, also report more depression, they feel like they can’t connect to their loved ones in the same way, because it senses smell as important they are, they may lose weight, some people put on weight, because because they can’t get the same flavor experience because we experienced smell through our mouth as well as when we sniff because they don’t get the same flavor experience they over eat, so they go for fried food or other sorts of texture things to try and make up for it. So there’s lots of things where smell is critical. And it can affect how people feel just maybe not as aware of it as we could be.

Josh Landy
Yeah, I mean, just the taste thing, right? Because we think of taste as being a separate sense. But we’re only getting a fraction of it through our tongue. And lots of it’s coming through that retro nasal movement of molecules. But I’ve gotten to you know, since you mentioned, since you mentioned, other things are kind of as a Christian, I kind of asking you, right isn’t Is that another thing that we lose? In other words, because smell is so connected with memory, and particularly emotional memory? Is that another special affordance of smell, it’s it’s, you know, it’s sort of the direct linkage between the the smell circuits in the amygdala and hippocampus that that binds these things together. So it’s not a real thing was Proust onto something about this connection between smell and memory.

Asifa Majid
It’s complicated. So there’s definitely some smells, that I think everybody has this feeling that there’s a certain smell, it really takes you back to a particular place. But it turns out that’s only for particular kinds of odors. So there has to be something that you experienced in a particular location or a particular time and then don’t frequently experience and lots of other places. So that moment becomes a capsule if you like, but just because something’s closely tied to autobiographical memory doesn’t mean that it can’t be tied to other aspects of memory to. So you know, we can look at photographs, and remember, oh, that’s when we were in holiday in this particular place. But that doesn’t mean that we can’t talk about the things that we see. So there’s no reason that smell couldn’t also be something that we are able to talk about just because it’s connected to memory.

Ray Briggs
I’m kind of curious about the loss of sense of smell and what happens over time. So is it the kind of thing that you can come back from and compensate for or is it just always this terrible loss?

Asifa Majid
Well, I mean, there are some really cool studies that show that olfactory training can work. So the olfactory receptors are things that can be regenerated over time. So actually, it’s one of the places that been shown that you get neurogenesis in adulthood. And so what can happen is if you have lost your sense of smell, you can take, you know, 46, common smells in your house and just deliberatively smell them, say, for 20 seconds every day. So you’re going to training regime. And this has been shown to improve all factory performance. So your sense of smell seems to get better. For certain some types of loss, this can be an amazing thing that you can do cheaply at home to help.

Ray Briggs
So what about enhancement? Like if I want to become a better smeller? Can I also do this kind of training?

Asifa Majid
Yeah, we’ve studied the wine experts. And in fact, it is something that you can train. So wine experts, they’re not just making it up. And they don’t only talk in metaphors, but you can learn to recognize a grassy smell and a wine or a raspberry smell. And in fact, if you look at wine reviews that different writers have produced, you can predict things about the wine from the descriptions that they give. So if I take a bunch of wine reviews, I can tell you, from the wine review, not knowing about the wine in advance that this was a red or a white wine, this was a particular grape, this was a expensive or cheap wine. So it means that the descriptions are actually telling us something informative about the wine. So over a bunch of studies, we’ve now shown that wine experts have better language, for wine, they have better imagery for wine and better memory for wine, but only for wine, it doesn’t generalize. So they’re no better at describing coffees, different types of coffees they know better at describing everyday smells, is something that they’ve trained for the specific thing that they’ve trained on, that’s what they’re good at.

Josh Landy
Okay, so we talked about different kinds of variation, right? So there’s a culture level variation, and perhaps temporal as well. Then there’s variation between experts and non experts. What about individual variation? I read somewhere that basically there, you know, there’s 800 or so olfactory receptor genes, but only 400 are expressed, and a slightly different set for everyone. So that’s why I understand the truth about cilantro. And it’s really disgusting. And so is that right? We do we each live in a slightly different sensory world?

Asifa Majid
We do, in fact. So there is a lot of variation. But I think we also underestimate the variation in the other senses. So you think, in Europe, 8% of men are colorblind. And that might be something that we don’t recognize, and sometimes people don’t even realize until much later in life unless they’ve specifically been tested on it. So there is variation of because as you said, there is a much larger class of receptors that can be expressed in different ways in different people. Maybe that does mean that we live in different smell universes.

Ray Briggs
You’re listening to Philosophy Talk. We’ve got a question from the audience. Can you tell us your first name and your question or comment, please?

Shahnawaz
Shahnawaz. My question is, you describe that in the modern society, we don’t we sanitize ourselves. So I was wondering if there is some people who live in, for example, developed countries where we are exposed to maybe more brand type smells, and some of them smells may not be so pleasant. So so people who have that experience of those different variety of smells, as compared to the people who live here and don’t have that much are exposed to only certain smells? Is there does that reflect in any way as far as their personality is concerned? or exposure to different smells? Does that have any bearing later on in adult life? Thank you.

Asifa Majid
I’m not sure about the relationship to olfactory exposure and personality. But there’s certainly differences in olfactory environments that people experience. What researchers are trying to establish now is what that means for how people think about smells and how they talk about smells. So some studies have shown that hunter gatherers are able to name smells better than non hunter gatherers, and that might be related to their subsistence or their foraging. And perhaps his sense of smell is more important. But when we look closely at hunter gatherer societies we find smell is important in all sorts of different places. So it’s important in their religious life, so they believe that certain smells shouldn’t mix because it makes their Thunder God angry. So for example, a brother and a sister shouldn’t sit too close together, and that’s breaking a taboo and when that happens, the thunder god funders, and so to ward off the wrath of the thunder gods. Traditionally, people would have cut their their calves with a knife and thrown the blood up to the founder God so the smell of the blood would appease the founder guide. First one practice that they have, they also theories that certain smells make them sick and other smells can make them better. They have theories about which kind how you cook foods or certain kinds of game meat can’t be cooked on the same fire. So it goes beyond just getting something to eat, it seems to be impacting almost every aspect of their life. And these are the kinds of things that we’re trying to find out now in different cultural contexts.

Ray Briggs
So we’ve got another question from the audience. Could you tell us your first name and your comments or questions, please?

Louisa
My name is Louisa. I was just wondering if any gender differences and a sense of smell. This is one of those controversial questions. There’s been a very nice meta analysis or looking at a bunch of different studies to see, are there any reliable findings across all of the studies that have looked for gender differences? You get quite reliable differences in being able to recognize and describe smells, women are better, obviously. But in terms of being able to detect and discriminate, the evidence isn’t so clear.

Ray Briggs
We’ve got another question from our audience.

Larry
Larry. Very interesting, very intriguing. You know, Wittgenstein’s take on the limits of my language over limits the world. But the big question winds up being, how does this fit into an evolutionary perspective? I don’t know who has dogs or, you know, their house is invaded by ants. But the feral gnomes, the sense of smell winds up being absolutely critical. So how would this fit into a more evolutionary perspective? Well,

Asifa Majid
in writing the 19 century, brocco made a distinction between asthmatic species, those that rely on their sense of smell and non asthmatic species that don’t rely on their sense of smell, humans being one of those, what Brocker notice was though, the olfactory cortex and humans was very small, in compared to the relative amount of space that was taken up by the olfactory cortex and other species. But there’s now fantastic evidence looking at different molecules across a bunch of different species to see how much of this molecule do you need to be able to have before you can see that something’s there, just the ability to detect it. And humans do really, really well, almost as good as dogs and many things, but definitely as good as many species that we’ve thought is super smeller. So as good as rats as good as pigs. Dogs are kind of special, though. So they are picking up odors that we can pick up on, but our sense of smell is a lot better than we thought in the last century.

Josh Landy
Okay, so this is something I couldn’t wrap my mind around, are we are we worse than dogs? Yeah, for a long time. Surely dogs are better than us at smelling. But then there are some studies, that seems just actually for some things. Like one example is the smell of cork wine where we can pick it up like one part and a billion or something crazy like that. And we can detect a very, very large number of individual odors. So is it kind of a mix where we’re humans are better at some things, and dogs are better at other things?

Asifa Majid
So there’s about 180 molecules that have been tested across a number of species, and we are as good if not better, at most of them. Dogs. So but dogs are special. They are able to detect things that we can’t detect when the other thing is until a few years ago, we thought that humans could discriminate around 10,000 orders. So tell the difference between two orders. And a study in 2014 showed that humans can distinguish a trillion odors. And more recently, it seems that the number is infinite. So we really are learning more and more about how sensitive our noses are, even though we’ve underestimated them all these years. Now that the studies are being done, it’s bringing to light new facts about what we can do.

Ray Briggs
So I love this, but I feel like just detecting substances at small concentrations is kind of not the only game in town.

Josh Landy
Ray is a dog owner, so…

Ray Briggs
I have a dog and I don’t do as much with dogs as my mom, but my my mom trains dogs to do search and rescue, where you can give them an article that a person has held. They can smell it and they can go match the smell and find the person in a field. I don’t think like any amount of training could get me there.

Asifa Majid
Well, you know, you’re saying that but a while back there was a study done in at Stanford, where a piece of chocolate was taken and put a cross the field. And humans tracked that trail of chocolate just by smelling it. So it’s something that you could do. I bet after this, you have to go and try.

Josh Landy
I am so delighted that chocolate is winning. And it’s not dogs. This is an incredible day for me. Now, if you say that, you know something negative about cilantro, my evening will be complete.

Asifa Majid
I’m sorry, I’m not with you there.

Ray Briggs
So we’ve got another question from the audience.

Christine
So Christine, and being among the scent allergy community, I’m wondering if there’s some kind of development of smell ometer, or smell or meter submillimeter. The same way that there are ways to measure other senses like light, color, etc. Such that we can look forward to some kind of regulations or some kind of limits that are acceptable or not for certain types of smells, or certain types of chemicals.

Asifa Majid
So smell noise regulations exist in in Europe, and in the UK, they are regulated in certain spaces. So some of it relies on just human judgment. So if you think this smell is too intense, over to longer time, you can put in a complaint, there are methods to measure specific types of odor. So for example, if you have a sewage plant, and it should be cleaning up its act, there are specific molecules that you can look for in that area. There’s also regulations around cooking smells. So those aren’t necessarily things people would find unpleasant. But in Europe, they are regulated. So people have to get the right extractor fans and make sure that smells are dissipating. But when you’re developing this kind of technology, the tricky thing is because there’s so many different types of smells, figuring out methods that can be sensitive to the things that you want to measure. So it might be that we need different tools for different types of smells. So there’s things that are being developed now, for example, to put into your fridge so they can tell you when things in your fridge have gone off. You can also just smell them.

Josh Landy
You’re listening to Philosophy Talk. Today we’re thinking about the philosophy of smell with us from Majeed from the University of Oxford.

Ray Briggs
How important is the smell of your home and your workplace? What advice would you give to designers and architects who wanted to make it better? How would you change your olfactory landscape?

Josh Landy
We’re coming to you from the Stanford Humanities Center for a program sponsored by the Symbolic Systems Program. We’ll take more questions from our live audience when Philosophy Talk continues.

Black Eyed Peas
We keep it stinky, we keep it stinky

Josh Landy
Welcome back. I’m Josh Landy. And this is Philosophy Talk the program that questions everything…

Ray Briggs
….except your intelligence. I’m Ray Briggs. Our guest is Asfa Majid from the University of Oxford. And we’re at the Stanford Humanities Center thinking about the philosophy of smell for a program sponsored by Symbolic Systems.

Josh Landy
So Asifa, I think you’ve convinced everyone in this room, if they didn’t already, believe it, that smell is incredibly important. So how do we keep that in our thoughts as we go about building human environments?

Asifa Majid
Depends on what kinds of environments I think people are thinking about it in all sorts of spaces. We can think about our well homes indoor spaces. So the fact that we do spend, I mean, some reports are saying we spend 90% of our time indoors, which is kind of incredible. And then you think, Well, you’ve probably cleaned your indoors, I hope you have. But probably with a cleaning product, that’s one of a few different smells. So we are not really giving ourselves a chance to really exercise their noses in the way that we could if we were getting fresh air. So when you open your windows, you’re gonna get samples of different sorts of odors coming in, which is good. In terms of outdoor spaces, we know that green spaces are good for health. And people have been thinking about the role that green plays and kind of our well being. But green also emits certain kinds of smells, and it seems that those smells might be good for us. So we can think of having planted trees, different kinds of vegetation as being good for biodiversity. Generally, it’s good for the insects and the animals are in our environment, but it’s also good for us.

Ray Briggs
So I want to know more about smell education. Also, like I want to get good at smelling the chocolate. How do I learn t o like name and distinguish smells better?

Asifa Majid
Just practice. So I think it is bringing it to mind taking some time to reflect on it. I mean, you know, we can put you in a regimen of distinguishing different chocolates, I can prescribe you exercises if you own, but I think it’s not just eating them without thinking about them. So you can try and name them for yourself, oh, you know, this was the raspberry flavored chocolate or this was the cherry chocolate or whatever, and just making that connection between what’s in your mouth and what’s in your mind.

Ray Briggs
Okay, so with vision, I can be like, that’s red, that’s yellow, that’s blue. And so in English, I don’t have anything similar for smell you I know you’ve studied a language where that is different. Could I could I acquire basic smell words?

Asifa Majid
I mean, you could but what you’re going to do with it, if it’s only you that lands them. So one of the things about languages, it’s a great tool to think with, but most importantly, we use it to communicate with. So what you need is people that you’re going to talk about this stuff with, and a reason that you guys would want to communicate about it. So build that social network.

Ray Briggs
So we’ve got another question from the audience.

Larry
Larry, again. I just wonder about the consequences of smell for behavior. And there was that older research done by I think it was Martha McClintock out of University of Chicago, where women’s menstrual cycle just wound up getting coordinated, living in dorms. So I wonder if you, you know, and that was quite some time ago. I don’t know what’s happened since then. But I wonder if you could comment on that.

Asifa Majid
There are some really great studies now showing that we are very sensitive to other people’s smell. So an area code social chemo signaling. So we can recognize when somebody else is sick from their smell. So in one study, researchers in Sweden brought people into a hospital and they injected them with something that caused them to an immune response. So we knew that they’re actually sick, or a placebo, and everybody gave consent, it went through ethics. And the orders that were taken from the people that actually had been injected with something that caused them to be sick, were recognized by a different participant of pool of people that that that order was a sick smell, and not a not sick smell, healthy smell. So we know we can recognize sickness and using similar paradigms, we know that we can smell fear, we can recognize a grandparent can recognize their grandchild from their smell.

Josh Landy
Newborns too, right, recognize their parents?

Asifa Majid
That’s right. So in a fantastic study done in France, the researchers assigned mothers to one of two conditions. So in one mums had to eat garlic while they were pregnant, the last trimester, or they had to aniseed for the last trimester. And then they tested the newborns as soon as they’re born. And they found that babies liked the smell. So if without those conditions and the general condition, babies don’t really like either of those smells, so they’ll turn their faces away from them. But in when their moms had ingested garlic, the babies smiled and turn their faces to it. And when their mom said it, and honestly, they did the same. So the chemical environment that the infants exposed to in neutral is already determining their order preferences. So there’s all sorts of information that we’re getting, what’s less clear, I would say now is whether there’s really something like pheromones. So I think they are balance of evidence. That’s not something that seems to be relevant for human behavior.

Ray Briggs
One thing about my smell environment that I want to kind of highlight is that I don’t like it to be loud in the same way that I don’t like my auditory or visual environment to be loud. And a lot of places I go to are scented in a way that is loud. And I wish people would stop. Could you explain what’s going on there?

Asifa Majid
Yes. And marketing became big, didn’t it? So I think there were studies on kind of going back to the house smells might drive behavior. Some early studies showed that if you pumped out the smell of bread in a bakery, people bought more bread. And you know, well, then it was like, Well, if you make some nice cookies, when you’re trying to sell your house, then maybe more people want to buy a house and you’ll get a better price. And that’s kind of gone into scent branding. So hotels are using particular sense so that now you feel you’re in a very luxurious hotel because it’s got this idea thing and I agree with you sometimes it’s overboard. I mean, if you walk into lush, I mean it’s more than Lush. So if customers are pushing back on it, then that might change what different companies are doing.

Josh Landy
I wonder if it’s maybe connect as a couple of things. I want habituation that, that the people who are working in these invites or trying to sell the house don’t notice anymore their neurons adapt. Right? And the other thing might be, again, individual variation, that I mean, could it be that some people are just more sensitive either, generally, to scent, or maybe it’s a specific scent, so that something that somebody else would think is very nice or just not noticeable at all, to somebody else smells loud>

Asifa Majid
There is that individual variation. So it can be for some people, certain orders are more intense than they are for others. And, you know, it’s funny, when you think about, you know, we know that repeated exposure to something can habituate the system, but also repeated exposure, can you make you more sensitive to it? So now you notice it, because it’s something that’s familiar. So how those things exactly play out. And what determines, which is going to happen in which condition, that’s something that scientists have to figure out.

Ray Briggs
So contrarily, like if I want to go to an exciting, but not overly loud smell environment? What are my options for making my life more olfactory really interesting?

Asifa Majid
Apart from the nature walk, so much would be a good way to get a variety of orders. I mean, I think developing Gurmeet smells and tastes is probably a good way to go. So instead of spraying on the perfumes, you know, trying different cheeses, trying different wines, noticing the differences that would make your life richer, make your pocket less rich, but might make your life richer.

Josh Landy
Can we come back to the question of human beings versus other animals. I’m really cute, because in terms of what scent does for us, there’s a number of things in common. So for example, you know, being able to know whether food is fresh or rotten, or whether there are poisonous chemicals in the air like hydrogen sulfide or whatever. And then yeah, you’re dating that seems like that’s held in common in humans Now, other animals, but but it seems like for the most part, we’re not as we’re not using our noses to detect predators, and whether it’s some other animal species are hopefully. So where do we sit, you know, in the world of, of animals in relation to how important smell is to us?

Asifa Majid
Is there a predator that you’re worried about that’s lurking trying to grab you?

Josh Landy
I’ll talk about it later.

Asifa Majid
I guess it’s I mean, that’s a question about what are all of the places where orders might be relevant. And I think you’ve picked out a good many of them. So definitely, in food and ingestion. And I think they’re like, you know, the relation to the obesity epidemic that we’re in is an unmarked, so the fact that we don’t eat mindfully, we automatically we’re not thinking about the smells and tastes that we’re experiencing, I think that’s worth lingering on is our first warning system. So you’re going to pick up that there’s danger from a gas leak, or that there’s a fire way before you’re going to see anything. And kind of going back to an example that you had earlier about her vision so much important for enjoying things. Imagine I give you a luscious chocolate cake is delicious. You can see the icing and now it smells of feces. How likely are you to put that in your mouth? No, what I want your visual system tells you so olfaction is giving you important information that should be determining approach avoidance and that’s the most basic thing underlying our behavior at all.

Ray Briggs
So on the one hand, I don’t want that cake. On the other hand, I have eaten durian, which smells terrible. Why should I be okay eating durian do I have to I overriding unnatural avoidance

Asifa Majid
Yeah, doings a fantastic example where what you get through the nose and what you get in the mouth don’t match. So when you sniff it, it has a maybe rotten I mean, it’s very difficult to describe it. But in the mouth, you’re getting this creamy texture, and it’s almost like vanilla. So there, you’ve got Miss matching information. And we can develop tastes or noses for things that seem unpleasant. So some cheeses, for example, have this kind of sweaty socks sort of smell, then yeah, that’s a delicacy or a fermented fish in Sweden is a delicacy. So we can override kind of natural warning signals that sometimes become these cultural delicacies just by again repeated exposure. That now makes something that would be disgusting, really delicious.

Josh Landy
Asifa, this has been incredibly enjoyable and very sensible conversation. Thank you so much for joining us today.

Our guest has been Asifa Majid, an experimental psychologist from the University of Oxford, where she researches the science of olfaction.

Ray Briggs
We’ll put links to everything we’ve mentioned today on our website, philosophytalk.org where you can also become a subscriber and gain access to our library of more than 500 episodes.

Josh Landy
And if you have a question that wasn’t addressed in today’s show, we’d love to hear from you. Email us at comments@philosophytalk.org, and we may feature your question on our blog.

Ray Briggs
Now… scratch him sniff him but do it fast. It’s Ian Shoales, the Sixty-Second Philosopher.

Ian Shoales
Ian Shoales… Exploring our olfactory scale leads one into the familiar territory of what humans have lost on our evolutionary path. Fur, for example, fangs maybe, talons, all of which survive kind of in werewolf myths. But not all of us can be werewolves. That’s a sad fact of life. Much of our smell detectors are now pseudogenes, though some might be reactivated, should it become necessary to detect the presence of a platypus, for example, in a darkened room. But what remains for us to smell, we smell intensely. Fishy smells still wrinkle our pretty nose, though lobsters remain odor free. Many familiar scents are named for the source. Strawberry smell for example smells like strawberries. This can get fuzzy. The teeshirt that I wear for two days may have a slight masculine musk that a woman might find attractive if her nose was stuffed up, I could dropped a few pounds, and we were standing in an orange grove. I’m horrible with perfumes myself. Call it Nuit De Paris, but I always think of it as eau de girlfriend’s neck. And many smells are conditional. You don’t want to smell vinegar at a wine tasting, but in grandma’s kitchen, it’s reassuring. Those with highly developed noses are like wine tasters, an army of adjectives and metaphors march at their command. Woody. Aftertaste of cinnamon. A whisper of cardomon lingers in the nostril. Thus smell and taste are linked to class. Wet wool is not classy. Salt air is, but not chlorine. When I was a lad, I read cheap mystery stories, often set in the bad part of town, where the private eye would encounter the “sickly sweet smell of marijuana.” I eventually set foot in a bad part of town, and you can bet I kept my nose peeled. Nope. New York City smelled like pennies, electricity, and evaporated urine, but never sickly sweet, that’s more of an L.A. thing, which smells like octane and jasmine. When I finally did smell marijuana, it was hard to tell, because everything smelled like beer. Now, marijuana just smells skunky. There are things we say we smell but we don’t. Blood in the air, for example, is just a newscaster’s way of saying it’s a football game, or a close election. Blood smells like iron, by the way, and humans don’t like it much. Wolves do! But werewolves are rare. There are also smells that have evolved from other smells, like grape gum from grapes. Supposedly. Wine, grape juice, gum. None of these actually smell or taste like grapes. We don’t like it when medicine tastes “medicine-y”. Which is why we have orange children’s aspirin. Which tastes like orange flavoring for children’s aspirin. We will never again know what children’s aspirin taste like in the wild. The smell on the breeze just means the orange grove has been burned down to make room for a cluster of ranch style homes. And what do they smell like? Again, household cleaners began with their own distinctive smells—with hard names and hard smells that made it seem like they were hard at work. Lysol. Listerine. Hydrogen peroxide. Bleach. But we got tired of that. So now cleaners join shampoo, detergent, deodorants, soaps, breakfast cereals to bring you lemon scented, orange, strawberry banana, lilac, ocean breeze, minty fresh. Prescription drug marketing took off in the late 1990s, spending close to $6 billion a year now. This is really a big niche market, for people who have diabetes related foot pain, mysterious headaches, eczema, joint inflammation, excess blood. But you’d never know what the drugs do from the names: Ozempic, Cromular, dupixent, humira. Could be drugs, could be new car models, could be Norwegian death metal bands. So again, they sound like they’re probably good for you, but after a while, I don’t know if it’s in our human genes, or if it’s a byproduct of marketing, which may also be in our genes, but sooner or later, it seems, we turn away from the science of it. It’s not Frankenstein, it’s Franken berry, the vampire is chocolate now, the werewolf is bitesized, the fresheners smell like pine, which doesn’t smell like pine, the medicine smells like hippie candles, and tastes like malted milk balls. Well, I say it’s all a weight loss grift, and I smell a rat. Maybe not, but I’m smelling something, and it sure isn’t teen spirit. I gotta go.

Ray Briggs
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Josh Landy
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Ray Briggs
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Josh Landy
Thanks also to Michael Frank, Todd Davies, and the Stanford Symbolic Systems Program, which has generously sponsored tonight’s episode.

Ray Briggs
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Josh Landy
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Ray Briggs
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Josh Landy
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Ray Briggs
Not even when they’re true and reasonable.

Josh Landy
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Ray Briggs
I’m Ray Briggs. Thank you for listening.

Josh Landy
And thank you for thinking.