Paul Rozin has called himself a vegetarian for some years now. “It’s for purely moral reasons: I don’t like the killing of animals,” he tells me in the living room of his 19th-floor apartment, in an impressive building in center-city Philadelphia. “There are vegetarians who ate meat all their lives and are disgusted by it now. We don’t know how that happens exactly, but I can tell you that if you have a moral reason for not eating meat, you’re more likely to find meat disgusting than if you have a health reason. Take people who are eating low-meat diets for their arteries: If it were to come out tomorrow that meat is the best thing for your arteries, which of course it could be, they would just bounce right back and eat meat.”
For Rozin, as he explains, his vegetarianism is based on a purely moral consideration. According to his own analysis, he should shudder when he encounters the smell of beef. But the professor has his own rules. He’s adopted a particularly flexible set of dos and don’ts that could give vegetarians the creeps. “I don’t care if there’s a little meat in something,” he says. And then clarifies, “I will eat meat if it doesn’t involve my participating in the killing of an animal.”
What do you mean?
“Say, for example, that my research partner, who is an omnivore, orders a hamburger and she only eats half of it, and says she can’t finish it. I can eat the other half because I have not supported the killing of an animal by doing that. I would eat calves’ liver gladly, but I wouldn’t eat veal. They don’t kill the cow for the liver, it’s a by-product. Or, if I’m served meat in a home where I’m a guest, I will eat it. I am not a ‘disgust vegetarian.’”
In fact, nothing disgusts Rozin, who speaks in terms of cold cost-benefit calculations. “In a very good restaurant, I will eat anything,” he says, “but in an okay restaurant I won’t eat meat or chicken, because it won’t be very good.”
So Rozin wants to have his steak and eat it, too. The slaughtered cow pains him, but he will have no problem eating beef if he’s not the one who ordered it. And this – let vegetarians beware – is valid not only for a cow or sheep. “I love dogs, but I would try dog meat if the dog were dead already – yes, I would try it once,” he admits.
One might well ask, and rightly, why the dead dog should be of a higher order than the cow on the plate. But for Rozin, that logic doesn’t stop with animals. “I would eat anything. I’ve eaten a lot of insects. I haven’t eaten a bat or a rat, because I haven’t had the occasion to, but I would have no problem about eating them. The most disgusting food, you could say, is human meat.”
Have you eaten human meat?
“No, because I’ve never had the opportunity. And of course I wouldn’t eat it if someone had to be killed for that purpose. But if the person is already dead and someone harvested some muscle and cooked it, I would try it. It probably tastes like other meat. I don’t feel disgust about the origin of the meat.”
Rozin, who will be 82 next month, is a professor of psychology at the University of Pennsylvania, and one of the best-known and most highly regarded food scholars in the United States. For almost 60 years he’s been studying why different cultures take to different foods and reject others – why it is that a particular food is considered a delicacy in one country but deemed revolting in another.
He’s easygoing, laughs a lot and talks about food with the passion of a master chef. His age hasn’t slowed down the pace of his research one bit. “I tend to study things that no one else studies,” he says with obvious satisfaction. One such realm of research is the notion of “disgust” or “revulsion” in culinary contexts. In fact, he’s been dubbed “Dr. Disgust.”
“Meat is the most favorite food of humans, it’s a very valued food. But it’s also far and away the most tabooed food,” he notes. “Nobody has asparagus taboos or carrot taboos; they’re almost all about animals. Sometimes you have parts of animals that aren’t eaten, such as kidneys, sometimes it’s only men who eat this, or only fertile women who can eat that. But it’s almost always about meat. Of 4,000 species of mammals, we Americans eat three: pigs, cows and sometimes lamb. What about all of the rest of the mammals? Why don’t we eat goats? Because they are disgusting! Almost all of the world’s disgust in this sphere relates to animal foods. What’s going on here?”
Rozin attributes the seemingly arbitrary attitude to meat to its deceptive nature. “Why is meat so popular? Well, it’s high in fat, and we like fat. But then it turns out that meat is not a biologically desirable food; little kids don’t love meat, it’s an acquired taste.” At the same time, he notes, “meat is high in protein and has a rich taste, it gives you ‘mouth feel’: You know you’re eating a piece of meat, it’s not like potatoes. Yet despite this, and even though the world is growing wealthier and more and more societies can afford to eat meat, increasing numbers of people are becoming vegetarians.”
There are three main reasons for this, he asserts: Meat is perceived as unhealthful, the meat-manufacturing industry is bad for the environment, and of course there’s also the issue of cruelty to animals. Rozin is moved by the latter reason, although that, as we’ve heard, doesn’t stop him from sharing a juicy red steak with you – as long as you’re the one who orders it.
The sushi mystery
Paul Rozin was an undergraduate at the University of Chicago, and in 1961, earned a doctorate in psychology and biology from Harvard. In the decades since, he’s traveled the world, studying the circumstantial, historical and anthropological contexts of people’s food choices. He analyzes the relationship between brain and body, between the biology we’re born with and the environment we grow up in, between what we’re served at home and what we eat with friends when we go out. For 10 years he was also an editor of the well-regarded scholarly journal Appetite.
“I worked on animal food choice for my PhD – why animals choose certain foods, how they learn, how they pick their food,” he relates. He then abandoned that field, until his then-wife, Elisabeth Rozin, decided to write a cookbook incorporating different types of cuisines.
Rozin: “Her theory was that each of the world’s major traditional cultures has a set of flavors that they add to almost all their foods. For example, Mexican food uses chilies, tomatoes and lime, and almost every Chinese dish has soy sauce, ginger and rice wine. She developed the idea that almost every major cuisine has a characteristic set of flavors, and that’s what makes it Chinese, Mexican or whatever. The question is, what happens if we apply a Chinese flavor principle to a food that the Chinese don’t use, such as potatoes. Does that make it a Chinese food?”
Rozin set about taking his wife’s theory one step further. “I got interested in the question of why a group of people who like a particular cuisine would want to apply the same flavor to all their food.” To that end, he decided to focus on something that seems to be the most unnatural choice to add to food, yet is an essential ingredient in every Central and South American kitchen: “It’s the most widely used spice in the world, and it tastes bad. I’m referring to chili pepper, which comes from Mexico and is eaten by more than two billion people, even though young children don’t like it and it has no special nutritional value.”
And it’s not just children that feel that way, notes Rozin, who spent five years in Mexico in the 1960s researching the subject: “Not a single animal in the village liked hot pepper, not the pigs and not the dogs. And they ate the garbage, so they were eating the same food the Mexicans ate, but they didn’t like chili peppers. So it seems like a uniquely human thing to take something that you don’t like, and eat it for a while, and get to like it. They took the negative signal that chili aroused in their brain at first and made it positive.”
Why does this happen? If you ask Rozin, it all begins and ends with persistence – and with the people in your milieu. If the definition of insanity, supposedly according to Einstein, is doing the same thing over and over and expecting different results, when it comes to food, a reverse process is at work, the professor explains.
“Generally speaking, if you do something that you don’t like doing, and you do it over and over again with people you care about in your social circle, in the end, some kind of change is generated. And it’s not just [about eating] chili. Coffee, too, is bitter and not tasty. And chocolate in its original form is bitter, which is the way it’s eaten in Mexico, where people mix chili with chocolate. There’s also ginger and black pepper, which are irritants like chili pepper. They irritate your mouth and produce a pain sensation. Horseradish affects your nose.
“There are also hard white cheeses, such as goat cheese or blue cheese. Cheese is spoiled milk. It smells bad. It smells like shit or vomit. You can give people two containers, one containing cat shit and the other one cheese, and they can’t tell which is which. And yet these foods became very popular all over the world. How does this happen? The big picture is that humans, and only humans, get to like all sorts of negative things that their bodies are trying to reject, but they keep at it for some social reason, until it converts to a liking.”
Does this mean that we can get used to anything? That no book is too boring, no CD is really bad, that every irritating person can become an intimate friend if we just give him sufficient opportunities? If you ask Rozin, the answer may well be yes.
“Take roller coasters,” he says. “People like the fact that their body thinks they’re plunging to death, but their mind knows they’re not. People like fatigue – they love running and their body says ‘Stop,’ and people love that. And people like to be made sad, but in a context that is not really threatening, so they go to sad movies and they cry. And again the trick is that your body thinks you’re threatened but you know you aren’t. It’s a case of your mind being over your body. The same process occurred with the chili, which opened up a whole range of things that only humans do, even if the body signals them to stop.”
Rozin’s next project will be a study of the psychological processes that characterize people who observe Jewish dietary laws. A father of four and a proud Jew, Rozin is an expert in the laws of kashrut, but as the reader has probably gleaned, its strict prohibitions don’t exactly obtain with someone who says that the food has not yet been invented that he’s not ready to try.
You talk about the huge popularity of chili, but in the Polish kitchen I was raised in, salt was the most my mother would add to food. How do you explain the fact that the process you’re talking about didn’t spread to Europe?
“Eastern Europe generally has a very bland cuisine, and the question you’re asking is why some cuisines are rich in spices and in flavor and others are not. What I found is that most of the high-spice cuisines have very bland, basic staples. The people who are less likely to add spices are those with a much higher meat cuisine, because meat is very flavorful compared to corn or rice, for example, as in the Mexican or Chinese kitchens. Spices add flavor to a very bland diet; they make it interesting, stimulating. The countries with the hottest foods are those with staples like rice and corn. And they tend to be less affluent and can’t afford so much meat, because meat is expensive and chili is cheap.”
For Prof. Rozin, sushi is perhaps the most salient example of his theory, according to which one can get used to almost any food. “Who would have thought sushi would become so popular in the United States?” he says. “It’s raw fish. And raw fish is disgusting. It’s also expensive, so it’s a limited market, but some of us have become avid sushi eaters. In 2015, there were about 3,800 sushi restaurants in the United States.”
How do you explain that?
“It’s aesthetic. It’s visually attractive, which most foods are not. You know, beef stew is not attractive. Not only is sushi beautiful, it is also upper class, and people like to do things they can barely afford because they like to make believe that they are richer than they are. You get shrimp, avocado – you can start eating sushi without actually eating raw fish.
“But for me the bigger question is not why sushi became popular but why no other Japanese food is popular. The Japanese make great food! Like yakitori, grilled meat, which is delicious. But of all the things the Japanese eat, we pick the most disgusting one and make it a beloved food.”
In the same way that people became eaters of sushi, Rozin believes, they should be able to learn to delight in a fine dish of insects. Certainly, he says, bugs deserve a chance.
Rozin: “I’m working on getting people to eat insects. Insects are a very good food. They are a great source of protein, they’re sustainable, they’re very nutrient and they’re easy to grow. But [in the Western world] people find them disgusting, even though about a billion people eat insects. We’re trying to figure out how to get people to overcome the disgust – which isn’t that hard to do, by the way, because you can use insect flour, so people don’t actually see the insect. And the flour tastes fine, like wheat but maybe a bit nuttier. Then you gradually increase the proportion. After all, children don’t know where bread flour comes from, either – it could be from anything. It’s a cultural thing.”
You talk about the taste of insects, but everyone knows that the visual element is critical when it comes to food. You know, a few years ago there was an experiment in which ketchup was colored green or blue, and no one would touch it.
“Some people are very flexible about food, others are totally inflexible, so you don’t worry about them. To make a winning product, you don’t have to appeal to more than a certain percentage of the population.”
Rozin talks about insects with the passion of someone who sees their penetration of the American food market as nothing less than a personal mission. Repeatedly, he insists on the great nutritional advantages of eating insects. Still, to judge by the results of at least one of his most famous experiments, it will be a long time before they land on our plates.
“So, we give people two clean, plastic cups, and we put two cartons of juice, apple and grape, in front of them, unopened,” Rozin says, describing the experiment. “And we open them, and they see us do that, and they each taste the juices and they tell us which they like more. We used apple and grape because they’re both quite transparent. And then we take out a dead cockroach and we put it in on a fork and dip it into one of the cups for a second, and then we take a birthday-candle holder, like what you put in birthday cakes, and we dip that in the other cup. Both of them are crazy things to put in juice. And then we ask people to rate the juices again, and they won’t even drink the juice that had the cockroach in it.”
But they would drink the other one?
“Oh yes, no problem. So the disgust from the cockroach has transferred to the juice. If you ask them why they won’t drink the juice, they say, ‘Well, cockroaches, diseases’ Then we use a sterilized cockroach, which is cleaner than your fork. We dip it in and we say, ‘What’s wrong? They’re safe!’ And they say, ‘Oh, but it’s a cockroach!’ They say it feels like they’re eating a cockroach, because it touched something that they like. And that’s a fascinating thing about disgust: It’s so powerful. And there is no opposite to that. You can’t take a pile of cockroaches and touch anything to it that will make them good.”
Sweet or bitter
Rozin’s studies, in which he is attempting to solve the riddle of personal taste and to deconstruct the relationship between innate and acquired tastes, is of considerable importance in light of recent controversies concerning the exposure of young children to different types of foods. Those who advocate breastfeeding and see mother’s milk as the most important and safest source of nutrition for infants, believe consumption of solid foods should begin at 6 months, at the earliest. Thus, the American Academy of Pediatrics’ policy statement: “Breastfeeding and human milk are the normative standards for infant feeding and nutrition. Given the documented short- and long-term medical and neurodevelopmental advantages of breastfeeding, infant nutrition should be considered a public health issue and not only a lifestyle choice.”
Others in the field, though, maintain that the earliest possible exposure to different types of foods is vital for the development of healthy, and above all diversified, eating habits. A case in point is a comprehensive study published in July 2017 in the journal Frontiers in Psychology, titled “How Infants and Young Children Learn About Food.” In it, researchers from Holland, Britain and Malaysia carefully analyzed 48 articles and studies concerning the eating habits of infants and toddlers, from birth until age 3. The concensus is clear: “The literature confirms that the tastes infants are exposed to at an early age have long-lasting effects on their liking of specific tastes.” The authors supply a host of examples, such as the assertion that “by 6 months of age most infants have a preference for salty foods, but the strength of this preference was related to the number of times the child had consumed salty foods during the previous week.”
Elsewhere in the article, the authors quote a study that found that “consumption of green beans by 4- to 8-month-olds tripled after 8 days of exposure [to the beans].” Their conclusion is unequivocal: “Exposing an infant or young child to a variety of foods at a young age is effective in promoting liking and intake of both exposed foods and other new foods.”
On this question, Rozin is solidly in the middle. He insists on the advantages of exposing children to different types of foods early on, but also reiterates that when it comes to choosing foods and developing different tastes, the social and environmental context is of greater importance than the eating habits our parents try to instill in us from an early age.
“The only congenital tastes that everyone has are for sweet and fat,” he notes. “Little babies at birth like sugar water, they lap it up, and reject bitter. And we like all sorts of other things with aromas, but that’s all acquired. It comes in at about three or four years, maybe a little earlier. I recommend to chefs and parents to add sugar to broccoli, so that children will agree to touch it, but they won’t hear of it. They believe that sugar is evil, but in practice, if you put sugar, or another sweetener, on vegetables, children will eat them.”
But that reinforces their tendency to eat only what’s sweet. What will happen when the child gets older and refuses to touch unsweetened broccoli?
“That’s not the case. Take coffee, for example. Almost everyone who starts to drink coffee takes it with cream and sugar at first, but look at all the people who like black coffee: Over time they drop the cream and reduce the amount of sugar. There’s no evidence that what we’re accustomed to at the age of 6 will accompany us for life – it’s certainly not true of food. We’ve shown in the lab that if you pair another flavor with sugar numerous times, people start to like the flavor even without the sugar.”
Can we say that some societies are more open and others more conservative when it comes to food, or is everything a matter of individual taste?
“My hypothesis is that the more you have a deeply ingrained fundamental cuisine, one that is very distinctive, the less open you are to other cuisines. We Americans don’t have a cuisine of our own, so most of the restaurants are ethnic. We have Chinese, Mexican and sushi. Whereas the French love their food, it’s really important to them and it’s really good, so they’re open but not as open as we are to other cuisines.”
Maybe that stems from French cultural pride and nationalism, and is less related to cuisine as such.
“We’re proud to be Americans, too – well, not these days But, if you say that I’m proud of American food, it’s not even clear what you mean, especially since pizza is one of those things. Food is a lot more than taste and nutrition. It’s a statement of who you are, what your social class is. If you have a native cuisine that’s deeply ingrained in your culture, you will be very attached to it. The French have healthier eating habits than the Americans. French people take longer to eat. Eating for the French is more than just the food, it’s the sociality. The French think of eating as an event, a social exchange; they don’t rush, it’s a totally different experience. Their kids don’t get macaroni and cheese, they eat what everyone else is eating. In our culture it’s like you’re in a cafeteria, and this kid can only like macaroni and cheese, and that kid can only like Cheerios and the other kid likes peanut butter, so they all get their separate thing and we don’t share food, which is the important thing.”