Freakonomics Radio - EXTRA: The Downside of Disgust (Update)

Episode Date: March 5, 2025

It’s a powerful biological response that has preserved our species for millennia. But now it may be keeping us from pursuing strategies that would improve the environment, the economy, even our own health. So is it time to dial down our disgust reflex?  You can help fix things — as Stephen Dubner does in this 2021 episode — by chowing down on some delicious insects. SOURCES:Paul Rozin, professor of psychology at the University of Pennsylvania.Val Curtis, late disgustologist at the London School of Hygiene and Tropical Medicine.Sandro Ambuehl, economist at the University of Zurich.Emily Kimmins, R&D lead for the sensory and consumer-science team for Kraft Heinz.Iliana Sermeno, former chef at The Black Ant. RESOURCES:“Stink Bugs Could Add Cilantro Flavor to Red Wine,” by Alex Berezow (Live Science, 2017).“Edible insects: Future Prospects for Food and Feed Security,” by the F.A.O. (United Nations, 2013).“I Hate to Break it to You, but You Already Eat Bugs,” by Kyle Hill (Scientific American, 2013).“Five Banned Foods and One That Maybe Should Be,” by Leah Binkovitz (Smithsonian Magazine, 2012).“Effects of Different Types of Antismoking Ads on Reducing Disparities in Smoking Cessation Among Socioeconomic Subgroups,” by Sarah J. Durkin, Lois Biener, and Melanie A. Wakefield (American Journal of Public Health, 2009).“Flesh Trade,” by Stephen Dubner and Steven Levitt (The New York Times, 2006).“Feeding Poultry Litter to Beef Cattle,” by Jay Daniel and K.C. Olson (University of Missouri, 2005). EXTRAS:"Why Does Everyone Hate Rats?" by Freakonomics Radio (2025).

Hey there, it's Stephen Dubner. We just finished publishing our series on rats, which reminded me of an episode from the archives that I thought you might like to hear. You will understand within the first few seconds why I was reminded of this episode. It was first published in early 2021, although we began making this episode in early 2020 and put it aside when the pandemic struck. Anyway, we have updated facts and figures as necessary. I hope you enjoy it. As always, thanks for listening.

If you sat down at my kitchen table and I put an insect in front of you, maybe a cricket or a grasshopper. Would you eat it? If you answered no, and I'm guessing you did, then why not? Your answer likely has something to do with disgust. But have you ever wondered why eating an insect is disgusting? Have you ever wondered why disgust exists? And what else do you find disgusting? You ever wonder why disgust exists? And what else do you find disgusting? Are there any universal disgusts?

Fecal material, for example, is inherently disgusting. Every person on the planet, with a few strange exceptions, finds fecal material something they want to stay away from. But once you get past poop, absolutes are hard to find. There are enormous variations in disgust. Consider, for instance, the animals we eat and don't eat. I'm a massive dog lover, but I would eat dog out of curiosity. In California, you cannot eat horse, whereas in many European countries, you have horse butcheries. I've never eaten roadkill, but I would.

I would eat human flesh. From an evolutionary standpoint, disgust has often served us well. There is good reason to not eat poop, as well as other disgusting things that might harm us. There's this real moment. But what if I told you that disgust is also holding us back, that it prevents us from pursuing strategies that could improve the environment, the economy, even our health?

Just try them. They're not as disgusting as they look. Today on Free Economics Radio, we will explore the roots and types of disgust. There's basically six different types of disgust. How incentives may change your disgust threshold. I brought buckets and tissues. I was afraid that somebody might throw up. We look into what psychologists call the mere exposure effect.

Medical students are disgusted by cadavers, but after they've dissected a cadaver, they're much less disgusted. And we ask what it might take to overcome. When in doubt, cover it with chocolate. This is Freakonomics Radio, the podcast that explores the hidden side of everything with your host, Stephen Dubner. We begin with someone who is an elder statesman and a pioneer. Nobody studied disgust 50 years ago. I did sort of start the modern interest in disgust.

Darwin wrote about disgust quite a bit. That's Paul Rosen. R-O-Z-I-N. People call me Rosen, but that's not right. Rosen is one of two scholars of disgust we'll be hearing from today. He is a professor of psychology at the University of Pennsylvania. Much of my work is about how humans relate to food

from anthropological, evolutionary, and psychological perspectives. It was Rasen who we heard say in the open of this episode that there are enormous variations in disgust. You have people who have almost no disgust. They certainly wouldn't eat feces, but they're not really disgusted by seeing animal feces or something like that.

And there are other people who will not blow their nose in a brand new piece of toilet paper. Because, you know, the poop association. As for Paul Rosin's personal disgust levels? I'm probably in the 20% of people who are least disgusted. Are there things that you are particularly disgusted by that aren't the common ones? Yeah. And I'm puzzled by it. I don't like really stinky cheese. Rosen calls himself a partial vegetarian.

I do not eat mammals or birds. However, I have a whole bunch of exceptions. For example, I will eat bacon. I will eat rejected food. So if someone's in a restaurant with me and they eat a hamburger and they only eat half of it, I, in principle, will eat it because it's going to go in the garbage.

I will eat calves' liver, which I love in the United States because it's a waste product. Nobody kills a calf for the liver. It was also Rozen who noted in the open of this episode that he would eat dog, roadkill, even human flesh. I'm curious what it tastes like. Whether I'd be disgusted by it, I don't think so, but I could be.

I've always wondered what parts of the human do you think would make for the best eating? Well, we in the United States only eat muscle. In other countries, they eat liver, they eat a lot of the viscera. I don't terribly like eating brain, though I have eaten brain enough. It doesn't taste bad.

I have eaten the ashes of one of my dear persons. That's the idea of endocannibalism. You love somebody and if they die, you want to keep them in some sense in your body. Whereas exocannibalism, which is very different, is eating your enemies. Would you like to see endocannibalism, as you've just described it, become more popular?

I have no desire for that, but if a religion practiced it, I don't think any current major religion does. I would think that's okay. Disgust doesn't exist in a vacuum. It has ramifications. So people who are very high on the disgust scale often have comorbidities with other sorts of neuroticisms.

So we found, for example, that people who are high on disgust are also high on sex disgust and it makes it very hard to make a lasting bond in a relationship. That is the other scholar of disgust we'll be hearing from today. I'm Professor Val Curtis. I'm a disgustologist. In Curtis's case, that means a background in engineering, public health, and evolutionary anthropology. I work on hygiene, sanitation, and water at the London School of Hygiene and Tropical Medicine. How does one become a disgustologist, and is that a large field?

There are very few disgustologists in the world. Surprisingly, there are not hordes of people screaming to study the science of disgust. But there are a growing number. And what got you into the disgust racket? It was a long journey, but there was a eureka moment that got me traveling this route. So I've been working on trying to understand behaviors that made people sick, mostly in developing countries, trying to understand why people were hygienic or weren't hygienic. For example, we'd done interviews in lots of different countries and I was asking people,

so when would you wash your hands? And they would say, well, when they feel sticky and disgusting. And I go, well, what do you mean disgusting? And I kept coming up with these lists of things that people all around the world found disgusting. And it was a motley collection of things. I couldn't figure out what connected that all together. But then a colleague asked me to explain the cause of a strange parasitic disease. And I looked it up in a book about communicable diseases. And suddenly I realized all these things that people found disgusting were sitting in the index to this book. And I'm going, hang on, vomit. People find that

disgusting. It makes you sick. Fallen hairs. People find that disgusting. Well, it's a cause of ringworm. Food that's gone off. That can cause typhoid, can cause diarrheal diseases. And the more I looked into it, the more I realized that there was a very obvious pattern here that the things that everyone around the world seemed to regard as disgusting, they were all things that might harbor parasites and pathogens and so might make us sick. So being an evolutionarily minded sort of person, I saw that this was basically an adaptation, something we have in our brain to make us behave in ways that avoid us getting sick. Paul Rosen agrees.

The core of disgust is almost certainly originally derived from a system to avoid pathogens, which are usually part of animal food, not plant food. And that's what led to his interest in disgust. What got me interested is that meat is the most favored food of humans, and also the most tabooed food. So I got curious why we should have such a strong negative emotion about a food that is highly nutritious and highly favored. Can you quickly define disgust for me?

Disgust was originally defined as a rejection or offense at the oral incorporation of an offensive substance. We added to that definition the fact that that substance is usually contaminating. That is, if it touches a otherwise desired food, it renders it inedible. So when a cockroach touches your sundae, that's the end of the sundae. It turns out there are different categories of things that might make us sick that we find disgusting. Six categories.

There's disgust about hygiene, there's disgust related to certain types of animals and insects, there's disgust related to sex, disgust related to people who are atypical in their appearance, deformed or not normal, tends to, unfortunately, evoke a sense of disgust. If you meet somebody with a lesion, with an infected wound, people do tend to find that disgusting. Types of food, particularly food that smells funny or has gone off. So those are the six

disgust categories. So those are the categories of things that generate disgust. What about our responses? We'll start with the physical ones. The first is called the disgust face. There are actually two disgust faces. One of them is a jaw drop, sometimes with the tongue sticking out, which is an oral rejection and maybe a closing of the nostrils.

There's another one which is primarily raising of the upper lip, and that overlaps a little with the anger expression. Then there are the verbal expressions of disgust. I've got a collection of the words from all over the world, and it's quite surprising how many use this onomatopoeic, blech or ych or ugg. It does seem to be almost a universal language. It's to do with the gorge rising. It's to do with this idea that your body is preparing itself for the ingestion of something that might make it sick.

So you're saying that that blech or blech or whatever is literally a pre-vomit sound, yes? Yes. And everybody would understand it wherever you were in the world. But beyond the physical expressions of disgust, there is an emotional component which goes beyond the things we put in our mouths. So my definition of disgust is a system that have evolved in the first place to help us avoid parasites and pathogens. But when you've got a system like that that is so useful and we use the same neurons to detect social disgust and moral disgust as we do to

detect pathogen disgust, I think it's reasonable to call it the same thing. That area is not as well defined. And so there's a big discussion now in moral psychology of the extent to which disgust is really a moral emotion. Jared Sussman When someone says that they are, quote, disgusted by another person's actions, something they consider immoral or unethical, maybe cruel, is that something that you consider disgust, an extension of the food disgust, or is it more, in your view, metaphorical? Dr. Michael O'Brien Well, that's the big issue,

whether it's metaphorical use of disgust or it's actual disgust. And one critical issue there is whether the same brain area is involved, for which there is some evidence, and also whether some of the other features of disgust, even a little sense of nausea, is involved. It does seem that when moral violations are cold disgusting, they often have a bodily component to them, like an axe murderer, not a bank robber. But what if I say I'm disgusted by the actions of, let's say, a politician? What he did disgusts me.

I can't imagine there's actual nausea attached to that, for instance. Well, I would say that's a more metaphorical use of disgust. When we say someone who steals, someone who's corrupt is disgusting, that's a little different from saying that someone who, say, burns the American flag is disgusting. So disgust is but one of a functional set of motives that make us do the things that were good for our ancestors. And they're there in all of us all the time and they drive a huge amount of what we do.

And it's very poorly recognized that that is the complete and necessary set of motives you need to be a human being. You've noted that people are much less disgusted by the notion of eating rotten food when they're very hungry, also that people are less disgusted by certain sexual matters when they're aroused. So how malleable is our disgust system? Our motives compete for our attention at every moment. And the one which is the strongest is the one that's going to win. So if it's been a long time since you've had a... What am I allowed to say on the radio?

Anything. Since you've had a shag? Can you say that? We don't say that, but you can, sure. So if it's a long time since you've had a shag, you're going to be much more likely to be attracted by the somewhat smelly, greasy hunk who's proposing himself to you than if you had a good one the day before. So it's not your level of disgust is going up and down, it's the trade-off that you're making that's going up and down.

If you haven't eaten for weeks the sandwich that has got mold on it, you might scrape the mold off, but you're going to eat it. OK, what have Val Curtis and Paul Rasen taught us so far? Disgust is driven by biological and quite likely evolutionary factors. It's got strong emotional components. It's also malleable and variable among individuals and cultures. The next question is, how useful can disgust be?

Considering it is an ancient force and that we're living in a modern world, should we learn to dial down the disgust in some cases? And are there other cases where we might wanna turn down the disgust in some cases? And are there other cases where we might want to turn up the disgust? This is one of the most effective handwashing campaigns ever. And can you incentivize someone to look past their disgust? The way the experiment works is people made decisions in five rounds, and each round was associated with one species of insect.

That's coming up after the break. I'm Stephen Dubner and this is Freakonomics Radio. We have been hearing that disgust can be a powerful deterrent to steer people away from negative behaviors or substances, but can it also push them toward positive ones? So, yeah, it is a double-edged sword. That's Val Curtis, the London disgustologist we heard from earlier. So, globally, some of the biggest killers are infectious diseases. As the COVID pandemic has reminded us, hand hygiene is an excellent weapon against infectious disease.

We've been working in programs all over the world trying to get people to wash their hands. But let's be honest, the benefits of hand hygiene have been known for a long time now. Some people just aren't very diligent. So Curtis got to wondering if she could apply what she had been learning about disgust. We used disgust to promote hand hygiene in Ghana. We did it not by talking about germs, not by talking about disease, but by making a very attractive little video where a rather well-dressed, but typical Ghanaian woman came out of the toilet and you notice that she doesn't wash her hands. And then she prepares food for her kids and you see her kneading this pounded yam and you see stains of something indeterminate on the pounded yam.

And then you see her feeding a piece of it to her child. And there's this real moment as moms watch this ad, they realize basically that the feces that she was dealing with in the toilet have actually got into the mouths of the kids. So it's a really powerful disgust message. Okay, so powerful I'm buying, was it effective? Did it change behavior? This is one of the most effective handwashing campaigns ever. The rates of handwashing more than doubled and it was still high several years after the campaign. So, that's a case where dialing up the disgust was fruitful. Another example, those horribly

graphic anti-cigarette ads you may have seen with rotten teeth and blackened lungs. But let's now consider the flip side. Rather than exploiting disgust in order to promote a certain behavior change, are there other behavior changes that are best promoted by reducing disgust? Well, the answer is yes. Paul Rosen again? For example, a lot of people will not drink recycled water, which is water which goes from sewage to pure water in a matter of minutes by being forced through a

membrane that only passes water. So it's pure water, but people are disgusted by it because they know it was in contact with feces. Now that disgust is a barrier to acceptance of this, which is a very efficient way of delivering water. So that's a case where there could be large environmental and economic gains from ratcheting down the disgust, maybe even geopolitical gains, considering that water scarcity is a source of great friction in many places. There is another disgust related mission that Paul Rosen is even more enthusiastic about, getting people to eat more insects.

Especially in the developing world where they're short of protein, insects are a great source of protein and though more than a billion people eat insects regularly, there are many who could use that protein who don't and they're disgusted by insects. As with recycled water, you can imagine the various gains from increasing the consumption of protein-rich insects, especially compared with meat, which is incredibly resource-intensive to produce. In 2013, the UN's Food and Agricultural Organization published a report promoting insect eating as an especially relevant issue in the 21st century due to the rising cost of animal protein,

food insecurity, environmental pressures, population growth, and increasing demand for protein among the middle classes. And how would these insects be consumed? There are generally two philosophies here. One is to make flour, which is a high animal protein flour that replaces say wheat or corn flour.

At low levels, you wouldn't even taste it. So that's one approach. As it were, sneak it in. And the other approach is to say, no, here are insects. As Rasen notes, more than a billion people around the world already eat insects. And they don't typically make flour. They will typically cook the insects maybe on a grill or they'll mix them in with other foods, but the insects are usually apparent. And what are the most popular insects? Often beetles, things like mealworms,

larva of insects and grasshoppers. So in Mexico, chapulines is what they're called. You can get a taco filled with grasshoppers. Chapulines is what they're called. You can get a taco filled with grasshoppers. But a billion people eating insects leaves another seven billion not eating insects. At least we think we're not eating insects. You already do eat insects. You're allowed to have five insect legs in a Hershey bar.

I've heard that. Yeah, look it up. We did look it up. That again was Val Curtis, by the way. And according to the Food and Drug Administration, there's actually an average of eight insect fragments per chocolate bar. Anything up to 60 fragments per 100 grams is acceptable, as is a small amount of rodent hair. And have you ever eaten a salad or peanut butter or canned tomatoes?

Have you ever had a beer or glass of wine? If so, then you have been routinely ingesting your fair share of insect all along. That said, most of us do not knowingly eat insects, especially in total, because they disgust us. So, insects are one of the types of things that we tend to find disgusting in as much as how closely they're connected with disease. Curtis, you will recall, is a professional disgustologist with a background in public

health and anthropology. I got to wondering whether the field of economics had anything worthwhile to say about disgust. Economists don't usually think about disgust. That's Sandro Ambule, an economist at the University of Zurich. They think, if anything, about moral repugnance because that puts limits on what can be traded in markets. Repugnance would seem at least moderately linked to disgust as it often centers around the human body. For instance, it limits how much you can pay people to participate in medical trials or

surrogate motherhood or human egg donation and so forth. There's limits on the incentives that you can provide for these kind of transactions. But is it true that incentives lead to worse decision making? We have all these laws that are based on this hunch. Laws against, for instance, compensating kidney donors or even offering compensation for breast milk? It's something that is empirically testable, but hasn't been empirically tested. So that's the main question that I want to answer.

He set out to answer this question with a set of experiments. Even though Ambuil says he was thinking about repugnance, he plainly understands disgust because he built his experiments around the eating of insects. Yeah, that's right. He used college students, of course, as his research subjects. The way the experiment works is people made decisions in five rounds, and each round was associated with one species of insect.

He used mealworms and silkworm pupae and a variety of crickets. House crickets, field crickets, and maybe the most disgusting ones are mole crickets. They are really nasty. In the beginning, I brought buckets and tissues because I was afraid that somebody might throw up. It turns out that didn't happen. Maybe because the people who knew they'd throw up were the ones who opted out of eating insects during the experiment because you were given that choice. In one

experiment, for instance, there's two groups of people. If you're in the first group, you'll learn that you're going to be given $3 if you decide to eat five mealworms. If you're in the second group, you'll learn that you're going to be given $30 if you agree to eat five mealworms. Now, after you learn how much money you're given, but before you make a decision, you can choose between two videos to watch to inform yourself about what eating these things is gonna be like.

One video is called, Why You May Want to Eat Insects. The other video is called, Why You May Not Want to Eat Insects. Ambul wanted to measure how both financial and informational incentives affected the decisions that his research subjects made. There was a separate experiment to see how much he'd have to pay students to eat a whole scorpion. So these are really large scorpions that are like as big as your hand and it takes about

$200 to $300 to make college students eat those or to make some college students eat those. In the interest of scientific equity, Ambul ate one of these scorpions himself. Take a plastic spoon, put a small shrimp on it, season it with some motor oil, and then eat everything, including the spoon. That's about what eating a scorpion is like. What was Ambuil trying to learn with this kind of experiment? I wanted to know if I offer incentives to somebody,

what do I do with their quality of decision-making? This goes back to the idea of whether financial incentives might skew someone's judgment towards selling their kidneys or eggs. What I'm interested in is whether if I pay people might skew someone's judgment towards selling their kidneys or eggs. What I'm interested in is whether if I pay people a larger amount of money, are they going to be more interested in watching the positive video than the negative video? And it turns out the answer to that question is yes.

In other words, the bigger incentive increases their appetite to persuade themselves that what they're about to do is a good idea. Among the research subjects who were offered just $3 to eat the insects, around a third decided to do it, even without access to a video. Among the subjects who were offered $30, nearly 60% decided to eat the insects without video access and more than 70% after watching the video about why eating insects is a good idea. So, what did this tell Ambule? This result looks like incentives are causing bad decisions.

But if you're an economist, as Ambule is, these are in fact good decisions. How so? If I offer you very little for doing something you might not like, well, what you want to make sure is that you don't say yes by mistake. You're okay with saying no, because there's not much to gain. Now, if I offer you a lot of money saying no by mistake, all of a sudden it's quite expensive. And so you become more interested in learning about the upsides rather than the downsides of the transaction. Now, how does this apply to Paul Rosen's mission of getting people to eat more insects? Well, economists, of course, love financial incentives, but there's a problem.

If you pay people to eat insects, they're less likely to engage with it after you remove the payment. The fact that they're being bribed to eat something may actually block getting to like it. Now, we don't know how people get to like things. We still don't know that. But it does seem that imposed incentives may block it sometimes, but on other occasions they may not. In other words, as all researchers like to say always, further research is needed. But with the incentives unclear, where does that leave you if your mission is to get people

to eat more insects? In psychology, there's this phenomenon called the mirror exposure effect. And what it says is just as you are exposed to something over longer and longer time periods, you start liking it. And Amule had noticed as he ran his insect experiments that the mirror exposure effect was working on him. So I was sitting there for a large number of hours putting insects into little plastic containers.

I started snacking voluntarily on the house crickets. Rozin has seen several examples of the mere exposure effect. If you drink recycled water for a while, not too long, just maybe a week, you won't even think about it anymore. The problem is getting over the disgust hump because people don't realize they'll cease to be disgusted once they get used to something.

We've shown that medical students are disgusted by cadavers, but after they've dissected a cadaver for a month or two, they're much less disgusted. And Val Curtis has seen the effect. In Uganda, we used to eat the flying ants that flew out once a year, and we'd catch them and fry them. They don't really have much disease connection,

and once you've fried them and salted them and you're having them with a few beers, the wriggly, sticky gooey nature of insects is rather forgotten. So basically people will eat insects that don't have too strong a connection with disease and the more you can distance them from a connection with disease, the more likely they are to eat them. We know that if people eat insects for a while, not for too long, maybe even 10 times, they'll get used to it and they won't be disgusted. They don't taste like meat,

but they can be crunchy and little nutty tasting. And so the taste won't put you off once you don't find it disgusting. What started is that small companies are making insects and they package them. One person I know puts them in dog food. So that's one way to get people to eat it is to have their pets eat it first. We're looking at these various roots that we can use. A lot of Americans will try a cookie if you say it's 20% insect flower.

The biggest problem with getting insects more into the world is cost because they're not mass produced. If we mass produced insects, like a Pepsi Cola or, you know, a craft or somebody made a serious attempt to do this, they would produce insects on a large scale. They'd use all the tricks they use with cows to make it cheap to breed better insects.

So one of the problems is to convince a big company to say, we're going to get down this road because there's a lot of business and potential public health. Coming up after the break, will one of the world's biggest food companies make that leap? So when you say insects, the first thing I want to know is what kind of insects. And the second thing I want to know is, do you have to see the insect? Can the insect be hidden?

I'm Stephen Dubner. This is Freakonomics Radio. We'll be right back. ["FREAKONOMICS"] I got to wondering, what would it take to persuade a big food manufacturer to get into the business of edible insects? My name is Emily Kimmins and I'm the Senior Manager of the Sensory and Consumer Science team for Kraft Heinz. Since we spoke with Kimmins in 2020, she has a new job title.

She is now the R&D lead for Sensory and Consumer Science at Kraft Heinz, which is one of the world's biggest food and beverage companies. They make Kraft mac and cheese, Philadelphia cream cheese, Oscar Meyer hot dogs and dozens of other products you have likely run

across. So I'm in charge of the taste tests for any new innovations that are coming out across all the brands in US and Canada. This means managing the company's professional tasters. We can only ask our professional tasters to work for two hours because even though we use them as analytical instruments, they really are just human. So if you ask them to taste more than, let's say, 10 to 12 macaroni and

cheeses in a two-hour period, it all starts to taste the same. And then we'll do outside consumer panels in the evening. All we ask consumers to do is react. Just do you like it, do you not like it? Kimmon says that simply surveying consumers about a potential new product, something with insects maybe, isn't useful. Consumers need something physical to touch and taste and hold on to to tell you what

they like and what they don't like. And the more different things you can give them, the richer your information is going to be. So, when it comes to new food ideas, volume is important. Because it's usually only about 10% that ends up making it out on the market. They may be really good ideas, but there's something that gets in the way. There's ingredients that aren't available. It's just too expensive to manufacture it.

There's consumers that are really interested, but not enough consumers to really make it make sense as a business. Okay. So, when we say insects, Emily Kimmins of Kraft Heinz says what? So when you say insects, the first thing I want to know is what kind of insects. And the second thing I want to know is do you have to see the insect? Can the insect be hidden? What form is the insect in? Maybe a worm can look happy and be, you know, maybe worms are okay, but cockroaches never okay. And is it cricket flour or am I eating a physical big old cricket? All of those things

matter. And it also matters what we're used to. So depending on where you live in the world, eating insects might be completely fine. Already part of my diet. No big deal. Give me some more insects. Have you heard about the insect cheeses? That again is the economist Sandro Ambule. There's two somewhat well-known insect cheeses. I think Sicily they eat what's called casa marzoo. Actually it's Sardinia where they eat casu marzu. Which is a cheese that they let sit and then flies come and lay their eggs into the cheese. And then you have the maggots crawling around

and people eat that cheese with the maggots. In some parts of Germany, meanwhile? The Germans have mite cheese. So they have living mites in the cheese. Before you turn up your nose at the notion of eating insect cheese, especially if you're an American, do you know what beef cattle raised in the US are often fed?

It's chicken litter. So the feces of chicken are processed and are then fed to cattle. And then you eat the cattle that have been fed on chicken sh**. All of this may or may not make the transition to insects more palatable for a company like Kraft Heinz. If we're talking U.S. and Canada, yeah, the biggest concern is the ick factor.

You need to understand how you can overcome the ickiness of the thought behind, I'm going to be eating some insects. That's the biggest thing. We have to make sure we can get it into people's mouths before they can judge whether they actually like it or don't like it. One of the biggest tricks that we have is blending familiar with unfamiliar.

So if you can blend it with something that they already know, they already like, you have a better chance of getting new flavors into their repertoire, like new fruits combined with strawberries. You'll see strawberry kiwi, you see strawberry goji berries, strawberry acai berry because, well,

I like strawberries so I'm willing to try whatever the other new thing is as long as it's still with strawberries. Of course, not all consumers think alike. There are classic consumers that say, don't touch my product, I love it, I want it exactly the way it is, I want it the same every time I get it, everywhere in the world.

For instance? That's a Heinz ketchup. I want Heinz ketchup to always taste the same. It's familiar, it's comforting, it's trusting. So we probably shouldn't expect Heinz to be slipping any insects in their ketchup, at least knowingly. Then you have other consumers that might be more adventurous.

Even Philadelphia cream cheese. They might be more adventurous consumers. They're dipping stuff in it. Cricket cream cheese. It could be a thing. Does Kimmins really think insects are viable even for a big mainstream company like Kraft Heinz, we asked her to rate the probability, with one being definitely and 10 being no way. I think for the general food world, it's probably about a five, because there are people in the world that eat it. It is available.

There are products that I can buy on the internet right now. It's not that inconceivable. I think for Kraft Heinz it would be a little bit harder. I think it would be at least a seven, but still possible. Yeah, it's still possible. You're not wasting your time. If you use a different language too, like, oh this came from Japan, like edamame, you know, those are soybeans. Well, it's edamame. It sounds fancy. I think that might be a actually brilliant way to do it. Make it sound exotic.

Make it sound adventurous. Insect, in Japanese, by the way, is conchue. It sounds great. A conchue brownie sounds delicious. And of course, there is this classic move. When in doubt, cover it with chocolate. It always helps. It's also worth keeping in mind how tastes change over time. I have my great grandmother's recipe book,

and there's a whole section on squirrels. And I would never think of making squirrel or serving it to my children today, but my mother and grandmother ate it all the time. So what we find repugnant in one era may be standard in another. This concept holds not just for what we eat, but what we believe, how we behave.

Slavery, for instance, was for centuries treated like a standard business practice. On the other hand, consider life insurance. Until the middle of the 19th century, it was considered, as the sociologist Vivian Azelzer once wrote, a profanation which transformed the sacred event of death into a vulgar commodity. If we are capable of making such big shifts

in matters like these, can it really be so hard to make insects appealing? In 2021, the European Union's Food Safety Authority ruled that muleworms are safe for human consumption. Two years later, the EU approved the sale of insect proteins in powdered and dried forms for human consumption. But what about human demand? Here again is Sandro Ambule. I mean, judging from my own reaction and the reaction of many people I have seen, I do think it's gonna be very, very hard

to convince even a sizable minority of the population to consume insects on a regular basis. I mean, no one thinks of kiwi or mango as being this very unusual food, but 50 years ago, they seemed very odd and very scary. So will crickets and millworms and things like that eventually become mainstream? Partly, if they taste good. I mean, they're not as disgusting as you'd think,

but they're just not very good. I think it's much more likely that everybody would become a vegetarian than it is that people would start eating insects on a broad scale. But I do need to say, I think sushi was at a similar point in the US a couple of decades ago. Things tend to start in restaurants first and then filter their way down from fine dining to casual restaurants to fast food and then end up in retail. There's always going to be adventurous people that are willing to try lots of different things and then if it tastes good and they're willing to say hey try

this it tastes good. Okay so we have the guacamole we We add some insects. We add grasshoppers or black ants. Right on top? Yeah, they go on top. Oh boy. Wow. Just try them. They're not as disgusting as they look. If people didn't know what they were eating, just try this. They'd think it was pretty good.

I met up with Paul Rozin, the Penn psychologist, scholar of disgust, insect advocate at the Black Ant, a modern Mexican restaurant in Manhattan's East Village. Are you hungry? I can eat. The chef is Ileana Sermeno. We also have the chapulines dish, which is the grasshoppers with avocado and fresh cheese. We also have the chapulines croquettes, which we mix the croquettes and baby grasshoppers. Can I prepare you one, Paul?

Sure. I'm going to give you a little bit bigger dose of ant than I... How many ants are you giving me? That looks to be about 100 ants. Wouldn't you say, maybe? looks to be about 100 ants. When you say maybe, they're pretty small. Yeah. This may be a good percentage of my total ant.

I can't keep my hands off the grasshoppers. They're addictive. They're like cocktail peanuts. You can buy these in stores, just dried grasshoppers. They won't be seasoned this well. I'm gonna grab one too. They have good texture. Now, you have a little salt in there, right?

Mm-hmm. What else? Some chili and garlic. You're a creative chef. Thank you. So, do you personally feel it's your mission to make insect eating more acceptable or you just happen to land here? I do like grasshoppers.

You go through Mexico streets and you can like grab a pound of grasshoppers and eat in it while you walk. It's healthier than chips and stuff like that. Is there any advice you could give generally on the idea of making insects more palatable to people? So when they come for the first time, I try to give them the croquettes. It's a little bit more soft.

They're delicious. They have cheese, a more similar taste. Then if they want to feel more adventurous, I will send like a whole dish of crickets or grasshoppers. I try to push it a little bit at a time. Our thing right now is black soldier flies. Black soldier fly larvae are the best because they are, it's not that they taste better but they have a short life cycle. They're great for the future. So you'll take the ants and the grasshoppers and the ant-flecked guacamole home?

Yeah, yeah. Thank you very much. And it was a great meal. Oh yeah, sure, thank you. Alright, if I come back I'll bring you some black soldier flies. I have ten pounds of them because that's the smallest amount I could get. pounds of them because that's the smallest amount I could get. That meal I shared with Paul Rosin at the Black Ant was in February of 2020. I'm sorry to report that the Black Ant closed last year. I'm even more sorry to report that Val Curtis, the British hygiene scholar we interviewed,

died in October of 2020. She was 62. The cause was cancer. I hope you enjoyed this bonus episode from the Freakonomics Radio Archives. We will be back soon with a brand new episode. Until then, take care of yourself. And if you can, someone else too. Freakonomics Radio is produced by Stitcher and Renbud Radio. This episode was produced by Matt Hickey with help from Daphne Chen and updated by Dalvin Abouagy. The Freakonomics Radio network staff includes Alina Coleman, Augusta Chapman, Eleanor Osborne,

Ellen Frankman, Elsa Hernandez, Gabriel Roth, Greg Rippon, Jasmine Klinger, Jeremy Johnston, John Schnars, Morgan Levy, Neil Carruth, Sarah Lilly, Teo Jacobs, and Zach Lipinski. You can find our entire archive on any podcast app, also at Freakonomics.com, where we publish transcripts and show notes. Our theme song is Mr. Fortune by The Hitchhikers, and our composer is Luis Guerra. As always, thank you for listening. The front legs taste the best. The gourmets know that. Thank you for listening.