Radio Replay: Yum and Yuck

[0] This is Hidden Brain.

[1] I'm Shankar Vedantam.

[2] Sarah and David Reza recently bought a place outside of Washington, D .C. They sound excited because this is the first time they're hosting both their families.

[3] We are making today a vegetable frittata with tomato, basil, and goat cheese.

[4] We've got home fries.

[5] Sarah and David wanted to start a new tradition.

[6] Cook brunch with ingredients from their home garden.

[7] The home fries have rosemary from our garden and the frittata has basil.

[8] from our garden.

[9] This is Sarah's way of going back to her family's roots.

[10] She remembers her mother doing the very same thing.

[11] I remember growing up, my mom had a garden, and she would always come back with, like, these tiny little tomatoes and be like, I provided for my family.

[12] Look, family, I grew this.

[13] And we're like, yeah, that's the smallest tomato ever.

[14] But there's something about being able to grow stuff and being able to give it to people that you love that's pretty exciting.

[15] So, yeah.

[16] My grandmother would always say that...

[17] This is Sarah's brother, Zach.

[18] The sharing food is important, but I'd say the most important part is being around the table.

[19] But food was the lure to get everyone.

[20] Food, yeah, exactly.

[21] Food kept us there.

[22] Yes, exactly.

[23] Food brought us together, but it's the company and the conversation.

[24] Today on Hidden Brain, the profound role that food plays in our lives.

[25] Food is not just nutrition that goes in your mouth or even pleasant sensations that go with it.

[26] It connects to your whole.

[27] life.

[28] We look at the culture and psychology that determine what we eat, what we spit out, and when we come back for more.

[29] Paul Rosen has been studying the psychology and culture of food for more than 40 years.

[30] He works at the University of Pennsylvania.

[31] Early in his career, Paul found himself pondering a question that few of us might think to ask, why do so many people across the world enjoy the hot, stinging pain of chili peppers?

[32] This question took Paul to a small village in Mexico, where chili peppers were as common as salt and pepper in the United States.

[33] They don't think their food tastes good without it.

[34] And the little kids don't like it.

[35] So something happens somewhere between two and five years of age.

[36] At the meals where everybody adult is eating the hot pepper and the older children are and they're all enjoying it and the little kid is thinking it's terrible.

[37] And after a while, some magic occurs.

[38] And the little kids like it.

[39] So I thought, well, we had a number of possible accounts.

[40] Some accounts involve something fundamentally biological.

[41] And presumably the biological explanation would be if you start eating it long enough, you're eventually just going to like it for biological reasons.

[42] Yes, that's right.

[43] The brain compensates for all sorts of things.

[44] We adapt to things.

[45] This is a case of more than adaptation where you're turning something that's negative into something positive.

[46] I mean, to me, that's an amazing thing, that we can start with something that's innately negative and make it really positive.

[47] So I said, let's take a look at the animals in the village.

[48] Because the dogs and the pigs eat Mexican food.

[49] They're eating tacos and hot sauce and beans and all of that stuff.

[50] So I went around the village and I first asked people, do you have any dogs or pigs that like hot pepper?

[51] And they said, what, are you crazy?

[52] I said, well, yeah, I mean, they eat it.

[53] And they said, that's ridiculous.

[54] I said, would you mind if I give the dogs a little piece of cracker with some hot sauce on and without and see what they choose.

[55] So they said, go ahead.

[56] And so I did go around the village with pigs and dogs.

[57] I put one cracker in front of them with hot pepper sauce and another without, and I'd see what they did.

[58] And it turns out that none of them ate the hot pepper first.

[59] They all ate the one with hot pepper because they're hungry, but their first choice was the one without hot pepper.

[60] So that I couldn't find an animal in the village that did what everyone over five years old in humans did, which was the gobobble.

[61] their stuff out and prefer it.

[62] So that suggested to me that it seems to be uniquely human.

[63] And so this is not just a question of people getting used to it and getting to like it, because the dogs and pigs are eating the garbage.

[64] The garbage is laced with chili peppers.

[65] If that was the case, that would be true for the animals as well.

[66] So what was happening in the humans, in the human brain, if you will, that allowed five -year -old children to fall in love with chili peppers and kept their canine cousins from liking it?

[67] Well, that's indeed exactly the question.

[68] We don't know how this happens, but we do know that where it happens is at the meals where the kids are eating with their parents and their older siblings, and they keep eating it because there's social pressure to eat it.

[69] Now, the animals keep eating it too because they're hungry.

[70] So it can't be just that they keep eating it.

[71] So it's really, to me, a miracle.

[72] And what I realized is that it's a miracle that takes place in humans all over the world, not just about hot pepper.

[73] It's also about liking coffee, which is bitter, and people don't like it originally, and they like it.

[74] And it goes outside the food domain.

[75] People like to go on roller coasters.

[76] Now, a roller coaster is a very negative experience the first time you have it, right?

[77] You think you're crashing to death, and your heart is pounding, and yet people pay to do this.

[78] Can you imagine a dog paying to go on a roller coaster?

[79] I mean, you know, it just won't happen.

[80] So we found that there's a whole range of things in which humans enjoy what is originally negative and they come to enjoy it as positive.

[81] This includes the fatigue of running.

[82] It includes sad movies.

[83] It includes being afraid in horror movies.

[84] This seems to be only humans.

[85] So our thought, and it's only a thought, is that what humans are enjoying is the very fact that their body thinks that something is bad, but they know it's okay.

[86] We call it benign masochism.

[87] The human have this special ability to appreciate the fact that they know that something that their body is saying is bad is actually good.

[88] And we have evidence for that.

[89] So, for example, for chili pepper, the favorite degree of hotness is just below the level of unbearable pain.

[90] They're pushing as far as they can to get their body to really scream, get this out of here, and yet know that it's okay.

[91] So it seems to be a very general feature of humans, which we tapped into by asking water, a couple of billion people like hot pepper.

[92] So in some ways the theory is that you start out not liking it and then social pressure, if you will, convinces you to try it and then you try it often enough that your body learns to adapt to it a little bit, but then eventually you start to like it for actually a slightly different reason.

[93] You're no longer liking it just because of the pure pressure or the social interactions.

[94] You're liking it because it gives you a sense that you're coming close to the edge of something thrilling.

[95] Is that the argument?

[96] Yes, there's something thrilling that is not threatening.

[97] Right.

[98] So, for example, if something is threatening, you don't get to like it.

[99] Like, people don't get to like serious pain.

[100] Right.

[101] It has to have something of the sense of it's not really threatening.

[102] And it even becomes funny.

[103] So in the case of disgust, people don't like disgusting things, right?

[104] But they make exceptions.

[105] They eat smelly cheese.

[106] And they come to like that smell in the context of the cheese, even though their body is saying, get this out of your mouth, it stinks.

[107] You once performed an experiment.

[108] on yourself, you were with your wife, I believe, at a Korean restaurant in New York City, and you did an interview with NPR back in 2015 where you told the reporter that it was one of the hottest things you'd ever eaten.

[109] Tell me that story.

[110] Well, my wife at the time was a cookbook writer and she was very interested in cuisine and we went to a Korean restaurant in New York and the people around us, they were ordering some dish that we didn't recognize.

[111] So we said to the waiter, we would like that.

[112] And he says, you don't want that.

[113] I said, no, no, we said, we really like to try new food.

[114] He says, you don't want to try that food.

[115] So this went on, and we won, of course.

[116] And he brought this dish, and it was unbearably hot.

[117] And we ate it because we were shamed into eating it by our own insistence that it was good.

[118] I have another story of a different sort.

[119] It also happened in New York.

[120] I had a colleague who had a dog, and the dog liked to eat dog poop.

[121] so they would go into Washington Square Park and with the dog and the dog would just hunt out of dog poop and eat it and it was just awful you know they hated it and the dog smelled and it so they went to a vet and the vet said why don't you put hot pepper on the dog poop because dogs don't like hot pepper so they go into Washington Square I want you to get this image Barbara's holding the dog on a leash and her husband goes with a shaker of hot pepper finds a dog turn and seasons it in front of of everybody with all this hot pepper, okay?

[122] And I mean, the idea of someone seasoning a dog turd is really pretty good.

[123] And then they let the dog go, and the dog ate it.

[124] And did the dog stop eating dog poop?

[125] No, no, because the dog liked dog poop more than it dislike the hotness.

[126] You know, people will put up with pain to do something they really like, right?

[127] Just as Paul has shown that the sense of taste is shaped by the brain, he's also done work that shows the same thing for appetite.

[128] In one study, he set a meal down before patients who had amnesia.

[129] Yes, the general view in most of the people who work on hunger is that hunger comes when your body reserves are low, maybe your blood glucose is low, various hormones come out, and you feel this sensation of hunger and you eat until it disappears.

[130] Now, there's some truth in that, of course, but there are many other higher -order things.

[131] So, for example, the cultural definition of what's a meal is very important.

[132] And after you finish the meal and have dessert, you stop eating.

[133] So to try to show this, we dealt with the two amnesic patients who were totally amnesic.

[134] They didn't remember anything that happened more than 30 seconds ago.

[135] But they were quite intact otherwise.

[136] So we fed them lunch in a situation where they were in a room without a clock.

[137] And we said lunchtime, and it was lunchtime.

[138] And we brought them a favorite lunch of theirs.

[139] We'd ask them what their lunch was, and they, of course, ate it.

[140] Then we took the plate away.

[141] There were no more signs that they'd eaten.

[142] And 10 minutes later, we brought another lunch and said, lunchtime, and they all ate it, three times each, the second lunch, completely.

[143] Then we took that away, waited 10 minutes, and brought a third lunch.

[144] Each of these were full -sized lunches.

[145] And most of the time they ate the third lunch.

[146] Twice, I think, one of them said, I'm getting a little stuffed, meaning their stomach was really getting full.

[147] But the point was that they're eating, when you served a meal, if it looks palatable, you tend to eat it.

[148] I was on a plane once flying to Chicago, and at three in the afternoon, they served a full lunch.

[149] Now, everyone had eaten lunch already, but six out of the nine people who, like I could see, ate that lunch, because it was lunch, and it was food, and it looked good.

[150] Probably wasn't good if it was airplane food, but, and they ate it.

[151] So a lot of what we do is we eat when there's good food around and when the situation is appropriate.

[152] Now, if we had left their first lunch and they saw the plate in front of them with the, there was pieces of chicken bone, they might have realized that I've just eaten.

[153] And when we give people, normal people, a second meal in the same way I just described, they don't say I'm not hungry.

[154] They say, I just ate.

[155] So it's fascinating because I think what you're saying really is that memory plays a huge role in whether we think we're hungry.

[156] Yes, being hungry is only one reason that we eat.

[157] So if you go for a full dinner, halfway through that dinner, you're not hungry anymore.

[158] But you're still eating the rest of the meal.

[159] That's right.

[160] So hunger can institute meals.

[161] The lack of it will probably discourage you from eating more, but there are other things that influence you too.

[162] When we come back, the role that culture plays in our experience of food, we'll also look at how you can serve more memorable meals.

[163] Stay with us.

[164] You're listening to Hidden Brain.

[165] I'm Shankar Vedantam.

[166] This is Hidden Brain.

[167] I'm Shankar Vedantam.

[168] I'm talking with psychologist Paul Razin, who has spent many decades examining the interplay between food, identity, and culture.

[169] Food is not just nutrition that goes in your mouth or even pleasant sensations that go with it.

[170] It connects to your whole life, and it's really a very important part of performing your culture and experiencing your culture.

[171] When Paul asked people about their favorite meals, they certainly mention eating at great restaurants, but they also talk about memories of meals that they shared with family and friends.

[172] Here's a very common answer that's very short for a home meal.

[173] Every Christmas Eve, my Italian grandfather and Greek grandmother would cook a meal consisting of creamy carbonara with bacon pieces throughout, homemade spinach pie and sausage.

[174] It was always amazing.

[175] Now, that's a lovely one, right?

[176] And it's not fancy, but you can see the emotion and the pleasure of it.

[177] And it's connected, of course, to the pleasure of family, not just to the pleasure of food.

[178] Yes, it's very social.

[179] Pleasure is only one factor when it comes to what we eat and how much we eat.

[180] Contrast and context can be important.

[181] Consider the difference between a tapas -style meal and a meal that's built around one large entree.

[182] In both cases, you can fill up your stomach.

[183] But it turns out, these have very different effects on your brain.

[184] As social scientists have found, most of us find it difficult to tell the, difference between the 10th bite and the 11th bite of the very same food?

[185] There's a whole line of modern decision research most associated with Daniel Kahneman, who got a Nobel Prize for it, and Amos Tversky, showing that, you know, people are not so rational as you might expect them to be.

[186] And one of the features of it is called duration neglect, which is people don't remember how long an experience is.

[187] They just remember the experience.

[188] So if you had a pain for 12 hours or a pain for one hour, two weeks later, what you remember is the experience of the pain, not how long it was.

[189] So this applied to food means that if you have the same food, a lot of the same food, it won't produce a very different memory from having a little of that same food because it's the memory of eating the food.

[190] So this raises a very important question that Conneman originally brought up, which is the distinction between your experience and your memory for the experience.

[191] Connman and others have shown, we've done some work on this too, that the ending of an experience is particularly important.

[192] So when you remember something, you're more likely to remember the end of it.

[193] And also, by the way, to some extent more likely to remember the beginning of it.

[194] And that would mean if you want to produce the best memory for food, you should put the best foods at the beginning and the end.

[195] Whereas most people think the entree is the best, which is in the middle and is the least remembered.

[196] We had Danny Kahneman on Hidden Brain recently, and of course he talked about the peak end rule and also about the difference between the experiencing self and the remembering self.

[197] Yes.

[198] And one of the implications of this, as you point out, this difference between experiencing a meal and remembering a meal, is it points to the difference between people who go to restaurants and order their favorite dish every time and people who go to a restaurant and order a new dish every time.

[199] How are these two strategies essentially catering to two different psychological impulsors.

[200] Well, that's an issue that we have looked at, and it's pretty clear, if you're going to order your favorite food, and you know you're going to order that before you go to the restaurant, there are actually three aspects.

[201] There's your anticipation.

[202] This comes from Kahneman, the anticipation, the experience, and the memory.

[203] Your anticipation of a meal is going to be higher if you order your favorite food, because you know you're going to have something great, right?

[204] Whereas if you can order something new, it's not even clear what you can imagine, because you don't know what it is.

[205] At the meal itself, You're probably going to enjoy your favorite dish more than a new dish because it's one of their best dishes you love it.

[206] There's a little risk in ordering something new.

[207] But if you order your favorite dish, you're not going to create a new memory.

[208] Whereas if you order a new food, you're going to create a new memory.

[209] We are looking at this, but we don't know yet for sure.

[210] If you're a person who generally values memories, then you're going to try to create more memories by creating new experiences.

[211] Whereas if you value anticipation and experience more, you will keep doing the same.

[212] wonderful thing.

[213] So how you value anticipation, memory, and experience affects how you're going to choose what activities you do.

[214] Let's just take an example, massage, okay?

[215] I like massage.

[216] I go once a month, I get a massage.

[217] It's pretty much the same.

[218] I can't tell you last month's massage was exactly this.

[219] So I'm going for the anticipation and the experience, which is very positive.

[220] I don't really create much memory from this.

[221] And I do it, and I like it.

[222] But it's very different from the way I eat, where I'm always trying to say, I want to enrich my mental menu listing, you know, my life experience of food.

[223] But people differ on this.

[224] We've been interested in trying to see if people are consistently different.

[225] We don't know yet.

[226] Think of a seven -day Caribbean vacation at a resort.

[227] Almost nothing happens, right?

[228] You're feeling good.

[229] The sun is good.

[230] you go in the water, it's nice, but there's no, if people say, tell me about your vacation, it's going to be a very short thing, right?

[231] So there's two kinds of vacations, those that are really high on experience and vacations that will give you a lot of experience, but there'll also be some hardship.

[232] You'll get tired, something may not work, something might be closed when you thought it was open, all kinds of things can happen.

[233] So it won't be a totally positive experience, but it will be a bunch of good memories.

[234] You've thought a lot about the differences between the American attitude toward food and the French attitude toward food.

[235] And you say that the French are more focused on what happens in the mouth, and Americans are often more focused by what happens in the bloodstream.

[236] I want to play you a short movie clip that illustrates this idea.

[237] Well, if it isn't diner, girl, what can I get you guys?

[238] What can I get here that has no sugar, no carbs, and is fat -free?

[239] Water.

[240] Water.

[241] Twice.

[242] So that was from the movie of Cinderella story, Paul.

[243] And I'm wondering if you can just talk a little bit about this, the American attitude toward food versus the French attitude toward food.

[244] I go to France, a fair amount.

[245] They seem to be enjoying their food more than we were.

[246] And interestingly enough, they're marginally healthier than we are.

[247] I mean, it's not a big difference, but they live a little longer, and they have less heart disease.

[248] And yet they eat a diet that's higher in animal fat than we do.

[249] It's okay if we're worrying about food.

[250] And the consequence of that is that we're going to.

[251] and live longer.

[252] But we seem to be worrying about food and not living longer.

[253] So that seems like a bad exchange.

[254] So we started a study of how French and Americans differ in the way they eat.

[255] And it's basically got two parts to it.

[256] One is how they think about food and the other is how their food world is set up.

[257] The French think about food as an oral experience.

[258] They think about eating as something that is giving them pleasure.

[259] They don't tend to think, about what's going into their bloodstream, how much sugar is in there, animal fat.

[260] So they're getting more pleasure out of food because they're not worrying about it.

[261] So, for example, if we ask French, when you think of heavy cream, do you think of whipped or unhealthy?

[262] They will say usually whipped, and Americans will say unhealthy.

[263] Now, it's the same thing, but they're thinking about it as an experience and we're thinking about it more as a health event.

[264] And in some ways, that actually might be a good thing, right?

[265] because presumably when you take more pleasure in food, you're focused on it, you're not necessarily just focused on getting stuff in your mouth or focusing on nutrition.

[266] The French, for example, seem to pay more attention to portion control than Americans, except that I don't know if they're thinking about this as control.

[267] They're thinking about this as the enjoyment of food, and once I'm done enjoying this bite, I'm done with it.

[268] Well, they eat more slowly, first of all.

[269] So they have more mouth experience because they don't swallow as quickly.

[270] They savor the food.

[271] So, I mean, if you have a chocolate bar, you can bolt it down in a couple of minutes or you can make a 10 or 15 minute experience out of it.

[272] And they're more inclined to the latter.

[273] We actually were able to measure how in McDonald's in Paris, how long people sat and ate compared to the McDonald's in the United States, okay?

[274] And we made sure they were French people in the McDonald's.

[275] They were talking French.

[276] the French people sitting in McDonald's sit there for longer than the American people sit in McDonald's.

[277] So they're eating more slowly, they're talking more, you know, they're not just bolting down food.

[278] Food is not fuel.

[279] Americans often, not always, treat food as fuel, whereas the French think about it not as a fueling, but as an event and experience.

[280] Now, in the food world, the big difference between the French and Americans is portion size.

[281] French traditionally serves smaller portions.

[282] If you look at a French cookbook, the amount of meat for four people per person is less than an American cookbook.

[283] In McDonald's in France, the portions are smaller.

[284] Now, if you remember our discussion of the fact that you eat what's in front of you, if it's pleasant, the amnesic patients, the French put less food in front of you, and so they're eating less and enjoying it more.

[285] And that seems to me to be a good formula.

[286] Now, they have other features of it.

[287] The French meal is a much more.

[288] elaborate event.

[289] People don't get up, especially at home.

[290] They don't get up in the middle of the meal and just leave the table.

[291] Everybody eats the same thing.

[292] So it's a social event.

[293] So I would say the French deal with food well in the face of the modern world where there's so much good food around that we can easily stuff ourselves and eat everything under the sun.

[294] They have managed to have a tradition which keeps it moderate and very pleasant.

[295] Paul Rosen has been studying the psychology and culture of food for over 40 years.

[296] He's currently at the University of Pennsylvania.

[297] Paul, thank you for joining me today on Hidden Brain.

[298] It's been a pleasure.

[299] Pleasure is not the only feeling we experience when we sit down for a meal.

[300] Food can also evoke other emotions, like disgust.

[301] After the break, we're going to delve more deeply into this emotion.

[302] Why do some things like smelly cheese delight us, while other smelly things, like sneakers, disgust us?

[303] We pose that question to research her Rachel hers and find out why she calls disgust.

[304] The instinct that has to be learned.

[305] You're listening to Hidden Brain.

[306] I'm Shankar Vedantam.

[307] This is Hidden Brain.

[308] I'm Shankar Vedantam.

[309] There's a simple explanation for why we have the emotion of disgust.

[310] It's a defense mechanism against things that could contaminate us.

[311] But we often have flawed intuitions about how disgust works, starting with what's clean and what's dirty.

[312] In her book, that's disgusting, psychologist Rachel Hurst talks about how the cleanliness of toilet seats compares to buttons on an ATM.

[313] Things that we actually touch a lot and have no idea or don't really think about how disgusting they are.

[314] Things like ATM buttons, actually our cell phones are just petri dishes of pathogens and germs.

[315] And most of us do not clean our cell phones very often.

[316] And yet we have this idea because of the associations that we know very specifically between toilets and waste from the human body that toilets are really, really filthy, and yet we don't give a second thought to things like keyboards or cell phones and other sorts of things that people are touching all the time and could be very dirty and contagious.

[317] I want to talk about a certain quality that disgusting things have, Rachel, which is that they tend to almost infect the things around them.

[318] As the psychologist Paul Rosen, who's done a lot of work on disgust, says a single cockroach will destroy the appeal of a bowl of cherries, but a single cherry doesn't make a bowl of cockroaches appealing.

[319] Why do disgusting things infect the things around them?

[320] Well, first I want to make a sort of flesh out a point there that I think is really interesting, and that is that good does not overpower evil, the way evil can overpower good.

[321] And so in fact, in other experiments, he found that the idea, for instance, of how could you purify something like Hitler's sweater.

[322] So people are told that Hitler owned this sweater and would you be willing to wear it under varying conditions or when could it become okay?

[323] And no form of cleaning could make it okay.

[324] Mother Teresa wearing it could make it a little bit okay.

[325] But in the case of Hitler's sweater, it had to be totally destroyed and burned in order for it to be okay.

[326] So good does not sanctify bad in the way that bad can sanctify good.

[327] Whereas just one spot of something bad like a cockroach, for instance, in a glass of water or milk or anything else, has the capacity to destroy the whole thing because negativity is much more pervasive and powerful from the way that we are built.

[328] And this is in fact adaptive because it's better to be worried about things that can harm us than overly excited about things which might be benevolent.

[329] I remember doing a story some years ago, Rachel, that looked at a slightly related idea.

[330] This was work by the sociologist Anne Bauer.

[331] and she was studying the market for used wedding rings.

[332] And she found that people were really reluctant to buy a wedding ring when they learned that the couple who had previously owned that wedding ring had gotten divorced, and people tended to want wedding rings where, you know, there had been some tragic love story, but the couple had been very happy together.

[333] So I'm not sure if it's exactly the same concept, but it really feels as if inanimate objects can sometimes carry with them the, I don't know, the spirit, if you will, it's an unscientific idea, the spirit of living things?

[334] Well, actually, it is very much the same concept, Shankar.

[335] And what you're talking about is something called sympathetic magic, which definitely plays a role in disgust and what we're disgusted by through association.

[336] The idea of once in contact, always in contact.

[337] So, for example, the ring that was on the finger of the woman who had a terrible marriage and ended up getting divorced, somehow, even though that ring is now in a jewelry shop, has nothing to do with that original couple whatsoever, the essence of that bad marriage is somehow still in the ring.

[338] And therefore, wearing that ring will therefore impart the bad marriage onto the new wearer.

[339] And somehow this spirit, as you said, will transcend and infect the new marriage.

[340] So it's, again, it's a form of infection.

[341] You have a very simple and interesting thought experiment in your book, which is, I'm not disgusted at the thought that when I drink a glass of water that there is saliva in my mouth.

[342] But if I spit in a glass of water and then I drink that glass of water, that seems disgusting.

[343] And of course, in both cases, it's exactly the same outcome.

[344] I have water in my mouth with saliva in my mouth.

[345] Why does it feel more disgusting in one case and not the other?

[346] So that's exactly a great point about the idea that disgust is about the outside coming in and contaminating our inside.

[347] So So while the saliva and the water is in our mouth, it's inside of us and even just take water out of the equation, just the fact that you have saliva in your mouth right now, we're all okay with that.

[348] But as soon as we spit that exact same saliva that's in our mouth into the glass and then look at that and then I'm telling you, now you should drink that, it all of a sudden, even though it's only been out in the air for seconds, has become contaminated by the outside and bringing it back into our body is now an entirely different proposition.

[349] And the fact also I think in this case that even though I know it's my saliva, it could be your saliva, it could be anybody else's saliva.

[350] Suddenly it becomes equalized with all the saliva that I know is out there that I definitely do not want in my mouth.

[351] So if someone, for instance, is talking at you and spitting while they're talking, you know, enthusiastically, we're disgusted by the fact that some spit could touch us.

[352] Just like once our spit is outside of our mouth, it becomes much less pleasant to think about taking it back in.

[353] There was a really interesting study done about sharing your toothbrush.

[354] And this study found that, so again, the idea that you have something in your mouth that somebody else had in their mouth.

[355] And it was found that the person that one would least like to share your toothbrush with is the boss that you don't like.

[356] So if you don't like your boss, you definitely do not want to share your toothbrush with him or her.

[357] However, the anchor person on your local news station, if they were attractive, was pretty fine to share a toothbrush with.

[358] And people in your direct family or your best friends were also okay to share a toothbrush with.

[359] And so this speaks to two things.

[360] One, familiarity and emotional connections.

[361] So people in your family are your best friends.

[362] You feel positively towards them.

[363] You're very familiar with them.

[364] And therefore, you sort of feel safe around their saliva.

[365] The good -looking person on the television, beauty equals health equals okay.

[366] But the person that you dislike or the person who's a stranger is a lot likely to be either more contaminating or because you don't like them, purely because you don't like them.

[367] They could be good -looking and you could know they're very healthy.

[368] But if you don't like them, then you don't want anything about them coming into you, as in their toothbrush.

[369] Context is key when it comes to disgust.

[370] In October 1972, a plane crashed in an isolated region of the Andes mountain range.

[371] There were 45 people on board, most of them rugby players traveling to Chile for a competition.

[372] Many passengers died upon impact.

[373] More died in the coming days because of the freezing cold and dwindling food supply.

[374] In the end, 16 people had to survive more than two months in the mountains, and their story has inspired movies, books, and documentaries.

[375] like this one from the History Channel.

[376] I said Nando, there isn't anything left in the storage compartments where we kept the chocolates and a can of sardines that we had.

[377] And Nando looked me in the eye and said, Carlitos, I want to eat the pilot.

[378] The people that had this idea and wanted to convince the other members that this was the only way they were going to survive did two things.

[379] One, they told the people to think of this as, what you're doing is eating just meat.

[380] So don't think about this as a person, kind of connected to, we don't think about eating cows and pigs so much as we think of eating pork and beef.

[381] So this is just meat.

[382] And the second thing is that they tried to justify this in another kind of a moral way by saying that the death of their compatriots would have been sort of a complete waste if it couldn't be used in this way to potentially aid in their survival.

[383] And so reluctantly at first, but then everybody joined in, ate the dead remains of the people that were around them.

[384] And another thing they did.

[385] We made a pact, and we did what people do now.

[386] People give blood to friends, to family members.

[387] They make organ transplants, you know, and we made a pact.

[388] We said, okay, hand in hand, if I die, please use my body, so at least one of us can get out of here.

[389] So the fact that this is about cannibalism and the people willingly resorted to this is something which has really caught our imagination because it really leads to this question of what would you do in that circumstance?

[390] Would you also traverse the line into this worst taboo?

[391] One of the things that I find interesting is that when I personally think about their behavior, I don't necessarily feel disgusted by what they did in the same way that if you told me that someone, one was munching on their, you know, neighbor's arm.

[392] You know, there's something about essentially having your hand forced by circumstances.

[393] You're acting in a way that is the only way you can possibly survive that changes the way I think about whether this is disgusting.

[394] Exactly.

[395] It's only really disgusting when it's a willful, unnecessary behavior.

[396] So like you said, you know, you kill your neighbor and then decide to eat them.

[397] But someone who is forced in the, to, this situation and the only way that they can survive is by resorting to an opportunistic situation that person's already dead.

[398] That's a lot different.

[399] But the act itself, eating someone who's dead, eating another dead human being is the same.

[400] And again, this is how our mind changes the behavior from being okay to something completely abhorrent.

[401] Rachel, you describe a case that took place in the 1990s.

[402] A man was stomped to death after propositioning another man, and when the case was taken to court, the defendant successfully used something known as the gay panic defense.

[403] You say this idea is rooted in a misconception about disgust?

[404] So this idea that, in this sense, using the gay panic defense, so in this case, someone was able to convince a jury that the idea of this man making a homosexual advance to him was so repugnant that being, you know, motivated to kill this person was somehow justified.

[405] And like you said, it actually was successful in the trial.

[406] Now, the concept that I think, so this is sort of, this is moralizing and this is getting people to become less judgmental towards the act of murder because of the fact that they felt a kind of a sympathy towards the feeling of aversion that this person must have had and therefore this sort of outburst of rage is somehow justified.

[407] The thing that's different about this, and I think this is an interesting point about disgust and what makes it different from anger, which I think it's often confused with, is that disgust is about recoiling from, moving away from, avoiding the stimulus that's making you disgusted.

[408] And if someone were truly disgusted by somebody else, they would not want to get all over them and beat them to get death and get their blood and everything else all over them because that would be even more disgusting if you're already disgusted.

[409] Instead, if I'm really angry, if I'm enraged by something, then I am attack, then I approach, then I can, you know, demolish you and get all covered in you, and it doesn't matter because I'm just in a rage.

[410] So really, the idea about this being discussed is wrong, and what it was is this person was affronted, you know, somehow morally, personally, whatever the case might be, and incited into such a rage that then he wanted to murder this person.

[411] So the idea of using disgust in this way is actually flawed because the person is not disgusted.

[412] They're just enraged.

[413] So that example of homophobia, Rachel, makes me think about an idea.

[414] In almost every society you go to, you see patterns of disgust that are modeled on social hierarchies.

[415] In many countries, you have the rich who are disgusted by the poor, or upper caste who are disgusted by lower caste, or people who are native citizens being disgusted by foreigners.

[416] What do you think explains this?

[417] It has to do with something more insidious, and that's related to our feelings about our social environment and the people that are in it.

[418] And the idea that foreigners and strangers and so forth are threats to our social, normal order, and that that then becomes somehow connected to our ideas about contamination and protecting us somehow.

[419] And the idea is that this somehow justifies and rationalizes racial prejudices and other kinds of prejudices because if we stay away from the unfamiliar and the foreign, because we don't know what those immigrants, you know, they could be diseased, and in fact, disease was often used as a way of anti -immigrant propaganda.

[420] This somehow justifies negative attitude towards them when there's no relationship between their ability to actually make us sick or not.

[421] In much of our life, disgust feels instinctive.

[422] When we see a cockroach on a kitchen counter or smell rotten food in the trash can, our revulsion feels hardwired.

[423] But Rachel says it's not.

[424] Our sense of disgust is learned.

[425] The things that disgust us not only reveal a lot about our culture, they reveal a great deal about our minds.

[426] She remembers an instructive episode from her own childhood.

[427] As we were driving in the car and it was a beautiful sunny summer day and the windows were rolled down and we were going by fields and everything was very pretty, my mother from the front seat said, oh, I love that smell.

[428] And so as I was smelling the same thing, and all kinds of nice things were in my visual scene, and my mother, who I love, said, I love that smell.

[429] I thought, okay, this is a great smell.

[430] And I then learned a few years later that saying that in response to that smell was a very big mistake.

[431] So the smell turned out to be skunk.

[432] So when I said, I love that smell on the playground with all a bunch of little kids around me, and they went, ew, disgusting, that skunk, oh, you're so gross and so forth and ran away from me. Again, so I become now the skunks, they all ran away from me. I realized that was not the socially appropriate thing to say, and so I kept that to myself for quite a while.

[433] But it turns out I'm not alone.

[434] There are actually people who like the smell of skunk, and that also leads into something interesting about our sense of smell.

[435] In fact, we don't all smell skunk in the same way.

[436] So both our minds and the way our noses, in fact, react to the chemical that makes up skunk is different.

[437] So unless you have an identical twin, your receptors in your nose are actually only yours, and nobody else shares them, even though there's a lot of overlap.

[438] So I buy the idea that we're all not smelling the same thing when we smell skunk, that the receptors in our noses and the way our brains work, we might be smelling different things.

[439] But it's also, what I find really fascinating about the story is that there is so much about disgust that is actually learned.

[440] You heard your mother.

[441] You have an association between your mother and the beautiful scenery around you, and you learn in some ways whether something that's something that's, a strong smell, is a positive smell or a negative smell.

[442] And in many ways, this runs counter to the way most of us, I think, think about disgust.

[443] We think of it as being this innate drive that if I find something disgusting, you're going to smell it, and you're going to find it disgusting as well.

[444] So I think that brings up a great way to think about the idea of disgust, and it is that it is the instinct that has to be learned.

[445] So once we learn what something disgusting is, we then feel disgusted by it, like, for instance, bodily products and toilet training and, you know, poop and so forth.

[446] We don't have a question about whether or not it's disgusting, especially if it's from somebody else where also is where meaning and context come into play.

[447] But we did not think it was disgusting from the get -go.

[448] So that is to say we were not hardwired or born thinking that poop was gross.

[449] In fact, many infants both like to play with poop.

[450] They like the smell of poop.

[451] They don't have any reactions to things, for instance, that adults in the same.

[452] community think of as positive or negative.

[453] In fact, a great demonstration I like to do is showing these facial expressions of babies getting either the smell of sort of sweaty socks and vomit versus the smell of vanilla.

[454] And some baby's faces to the sweaty socks and vomit are making big smiley faces and others to the face to the smell of vanilla are making what we would call disgust faces.

[455] So, you know, there's nothing hardwired about the reaction either to smells or to things that are disgusting.

[456] But once we learn what the meaning is we then stick to it, except for when the context can make it very confusing or the context changes the way we perceive something.

[457] I love this idea that in many ways our notions of disgust are constructed.

[458] I understand that Americans like wintergreen flavor chewing gum, but people in Britain, not so much.

[459] So in the UK, winter green mint is used exclusively in toilet cleaning products and in some medicinal bombs, like things you would rub on your skin if you're in pain.

[460] And so they're connected, the smell is connected to either being in pain or cleaning the toilet.

[461] So not good.

[462] In the U .S., however, the scent is used in candies and in gums.

[463] It's connected to the taste of sweet.

[464] And sweet actually is innately positive.

[465] So tasting sweet plus smelling something that's going to be good.

[466] And we don't have any connection to cleaning the bathroom or being in pain when we smell this odor.

[467] And so as a function of the connections that we have learn to it and what the meaning is, this odor, which in it of itself is totally, you know, agnostic.

[468] It doesn't have meaning one way or the other, becomes good or becomes bad as a function of that.

[469] So the British and the Americans are divided on the subject of wintergreen, but I'm absolutely sure they'd come together when it comes to eating bugs.

[470] It ain't happening.

[471] My heart's pounding.

[472] Oh my God.

[473] They look like crickets.

[474] There's no sugar I'm about to throw up if I stay here.

[475] Oh, I don't want to do it.

[476] Those are reactions from a couple of our NPR co -workers when we presented them with a plate of dried crickets and asked them to take a bite.

[477] Can I go fill up my water bottle?

[478] Can I have a chaser?

[479] I'm cool bugs as long as they're outside.

[480] I'm not sure how cool I am with them be in my mouth.

[481] It's disgusting.

[482] It's insects.

[483] Look at it.

[484] There's exoskeletons everywhere and pieces of legs.

[485] This is gross.

[486] People eat this?

[487] There's a couple of things which discussed us about bugs.

[488] One of them is that we don't consider them to be food.

[489] Now, there are cultures, especially in Southeast Asia, that do consider all kinds of bugs as food.

[490] And if you were to go to Thailand, you'd see Madagascar hissing cockroaches on display in the market where people are actually buying them to eat them up for meals and prepare them in all kinds of ways, which apparently, although I don't know personally, can be quite delicious.

[491] But the idea of what food is is a really interesting, because this again speaks to how disgust is learned.

[492] And when we decide that something is edible, then it's okay to eat.

[493] And other cultures think differently about that.

[494] The other thing about bugs is that they move in a way that seems to be related to one of the aspects of disgust underlying why we don't like them.

[495] And this is actually somewhat connected to bodily fluids.

[496] So bugs move in a kind of a jerky or slithery or slimy kind of way.

[497] And those kinds of things actually have a similarity to body products that we are also disgusted by.

[498] So being disgusted by slugs, for instance, is to do the fact that slugs are similar visually to feces.

[499] So there is this kind of continuum about our association between what bugs are and what bodily fluids are that were disgusted by.

[500] So there's a variety of reasons why bugs are disgusting.

[501] One of the things in your book that caught my eye was even in the same country in different periods of time, our attitudes about what's disgusting have changed or can change enormously.

[502] I understand that a few centuries ago, lobster was not quite seen the way that it was in Massachusetts.

[503] No, lobster was actually considered vermin of the sea and only suitable for slaves.

[504] And in fact, there was a slave uprising against the idea that it was completely cruel and unusual punishment to give people lobster to eat more than three times a week.

[505] And today, we might say, oh, how lucky to be able to afford to have lobster three times a week.

[506] So it's conceivable then maybe in a few decades or maybe in a couple of centuries from now.

[507] We will think of eating cockroaches and crickets very differently than we do today.

[508] In fact, there are some people who would argue that insects are a very efficient source of protein and they're plentiful and in some ways consuming insects might actually be good for the environment in all kinds of different ways.

[509] I'm personally a vegetarian, so I don't know if I'll ever subscribe to eating crickets and cockroaches, but presumably our attitudes towards eating insects could change.

[510] Absolutely.

[511] So the idea also, one of the things that made lobster disgusting and unappealing is that it was slave food, it was prisoner food.

[512] So these people, these are bad people in the kind of the hierarchy of humans.

[513] And therefore, it's okay for them to eat things that are possibly that we would consider disgusting, but not okay for me, you know, the elevated person or whatever I think of myself as being.

[514] And right now, the way we think about, insects is similar to that.

[515] So people who are not like us, people who have to resort to the, you know, the last measure as possible for survival, they're going to sub, you know, debase themselves to eat insects.

[516] But if we think about it entirely differently, so if we re -moralize the story and instead make eating insects about saving the planet and make it a virtuous thing to do rather than somehow a debase thing to do or a last resort thing to do, we could, in fact, make it a very positive thing.

[517] While some of our co -workers shrank at first when they held the cricket in their hand...

[518] The more you look in his eyes, the less you want to eat it.

[519] The looks of fear and disgust faded after the first crunch.

[520] Cheers?

[521] Cheers.

[522] It's just like chips kind of.

[523] It's good.

[524] It's a little earthy.

[525] It's like sunflower seed or something.

[526] Yeah, it's like can I get like a basket of these like before my needle comes?

[527] Along with the whole crickets, We also provided samples of delectable protein bars made of cricket flour.

[528] I chose peanut butter and chocolate.

[529] If you didn't tell people if this was cricket, they wouldn't know.

[530] It's good.

[531] It's not like there's big chunks of cricket in it, so I like it.

[532] Not bad at all.

[533] I'm trying to not be so like American, you know, because like everyone else eats crickets.

[534] It is a luxury to be able to be disgusted from the very basic level that if you don't have anything else to eat other than someone who's dead beside you or the cockroach on the floor, then you just do not get disgusted by that because you have to do it in order to survive.

[535] So it's a privilege to be able to say, no, I'd rather not have that dead person or that cockroach.

[536] I'd rather have that hamburger or the steak or that beautifully prepared dish of portobello mushrooms.

[537] So the ability to say that we are disgusted by something actually comes from the privilege and the luxury of having abundance and having enough to sustain us that we can make the decision that we don't want this and we'd rather have that.

[538] Rachel Hears is the author of That's Disgusting and The Scent of Desire.

[539] She also had a book out at the end of 2017, Why You Eat, What You Eat.

[540] Rachel Hears, thank you for joining me today on Hidden Brain.

[541] It's been a pleasure, Sankar.

[542] Thank you for having me. This week's show was produced by Thomas Liu and part of it.

[543] Shah.

[544] It was edited by Tara Boyle.

[545] Our team includes Jenny Schmidt, Raina Cohen, Laura Querell, and Camilla Vargas Restrepo.

[546] Special thanks to Monique Laborde.

[547] Anya Grunman is NPR's vice president for programming.

[548] For more Hidden Brain, you can follow the show on Facebook and Twitter.

[549] Please be sure to subscribe to our podcast.

[550] I'm Shankar Vedantham.

[551] Thanks for listening.

[552] I'll see you next week.