“Foods for Enjoyment,” and creating bonds that transcend family. Interview with Primatologist Junichi Yamagiwa on “Shikohin” (Part 1 of 2)

Food items such as alcohol, tobacco, tea, and coffee are not consumed for any nutritional value, but for enjoyment. These food items are referred to as “shikohin.” Why did mankind pursue these items that, at first glance, seem to have little purpose in survival?

“Shikohin” is a term that is difficult to translate outside of Japan and unique to the Japanese language. It is said that the first person to use this term was Ogai Mori, who described “shikohin” as something that is “a necessity in life” that is also “a poison” in his short story “Fujidana” published in 1912. Being both a poison and a medicine, “shikohin” is surrounded by ambiguity. In the DIG THE TEA series, we will explore modern day “shikohin” and its role in our society through interviews with leading experts both in and out of Japan.

For our first interview, we visited anthropologist and primatologist Junichi Yamagiwa. Through multiple fieldwork, Yamagiwa has studied the behavior of primates such as gorillas and Japanese macaques. By comparing the behaviors of primates and humans, he has explored the question of what it means to be human. As Yamagiwa speaks to us about his experiences, we start to understand the significant role “shikohin” plays for us humans.

Interview&Editing : Masanobu Sugatsuke Editing support : Masaki Koike, Takumi Matsui Photo: Mayuko Sato

Do gorillas and chimpanzees also enjoy “shikohin”?

── First we want to ask about the origins of “shikohin” from a pre-modern day human, primatological stand point. You have been studying apes (the closest relatives to humans such as gorillas and chimpanzees). Have you found that they seek out “shikohin,” or other items for a similar purpose and enjoyment?

Yamagiwa: Apes are known to enjoy alcohol and tobacco. For example, there are times that gorillas and chimpanzees in zoos are given alcohol to drink to relieve stress. 

In a book written by Koichiro Yoshihara, a chimpanzee keeper at Tama Zoo, there is a story where he describes a male chimpanzee that became depressed and withdrawn after losing a fight to a younger male chimpanzee. Koichiro gave him some whiskey to cheer him up. The whiskey drink put so much energy back into that chimpanzee, it ended up defeating the younger chimpanzee in the next fight and helped it regain his confidence. 

In zoos in the US, there are stories of similar cases. There are times that gorillas become withdrawn and refuse to come out into the open due to the constant stress of being watched by visitors. They give them some alcohol and it cheers them up enough to come outside. 

Apes also enjoy smoking tobacco. I once encountered a male chimpanzee in an animal orphanage (a facility that cares for animals who lost their parents) in Kenya. That chimpanzee loved to smoke. He was constantly begging visitors to give him cigarettes. 

At the Japan Monkey Center (one of the biggest primate zoos in the world) where I used to work, there was a female chimpanzee who loved to smoke. She used her own hand as an ashtray and it was clear that she loved the taste of tobacco. 

── That must have been a surprising sight. Outside of the zoo, are there examples of apes showing similar behaviors?

Yamagiwa: Not with alcohol and tobacco, but there are examples of apes putting things in their mouths that are obviously not meant for eating. 

I have looked at over 10 thousand specimens of gorilla droppings. In the droppings we found full leaves of commelinae, which have a soft furry surface. They were neither crushed or decomposed. 

Usually, when a gorilla eats leaves, it picks a bunch at once and chews them into pieces. However, these commelinae leaves were swallowed whole. It is clear that the purpose of their consumption was different from their regular diet. 

A weak digestive system encouraged the birth of “shikohin”

── Does it mean that the gorillas were eating the leaves as “shikohin”?

Yamagiwa: It is very likely so. I believe they were swallowing them whole to get rid of parasites. We have found these kinds of leaves in the droppings of chimpanzees with parasites entangled in them. 

At the same time, it is also possible that it offers some kind of pleasure, like “shikohin” does. The soft furry surface of the leaves probably provides a cleansing sensation as it travels through the digestive system. 

Similar behavior has also been observed in East African chimpanzees. It is likely that they are using vernonia amygdalina leaves (a plant of the Asteraceae family) as a kind of medicine. This leaf is very bitter and it has the effect of killing parasites. It is possible that these apes consume these leaves when they are feeling unwell to get rid of parasites from their digestive system. 

I think when they consume it, they feel relief in their stomach and intestines and feel better. What starts as a medicine gradually turns into consumption for the mere purpose of pleasure, like a “shikohin”. I believe that this is what leads apes to begin consuming “shikohin”. 

── Do you believe that this kind of behavior was passed onto humans and what led to other “shikohin”?

Yamagiwa: Yes, I think so. These behaviors are not seen in monkeys. Monkeys have a lot of bacteria in their digestive system so they are able to digest slightly poisonous leaves or unripe fruit and it is difficult for parasites to survive inside of them. 

They don’t have a need to consume leaves for the purpose of killing parasites, and even if they did eat them, their bacteria will break them down. On the other hand, apes and people have a weaker digestive system compared to monkeys. That is what brought about the use of “shikohin.” 

── So a weak digestive system led to the birth of “shikohin”.

Yamagiwa: To expand on that point, I think that the weak digestive system eventually paved the way to the consumption of alcohol. When alcohol is absorbed into the body, it turns into acetaldehyde, which is highly toxic. Many primates do not have the enzymes to break this down, but for some reason, apes and humans do. I think that a mutation that enables the breakdown of alcohol occurred at some point over 9 million years ago, when the ancestors of gorillas and humans are said to have split.

Referring to the research of Hiroki Ota, a population geneticist, I think that this mutation occurred in order to eat overripe fruit. When fruits fall to the ground, eventually they will rot and ferment and produce alcohol. For apes, which have a weak digestive system that can only digest ripe fruit, those who could eat the slightly rotten, over-ripe fruit, must have had a higher survival rate. This would have promoted the evolution of enzymes for breaking down alcohol. 

It is said that the first alcohol made was wine (fruit wine). The sugary fluids from the ripe fruit would accumulate in the hollows of a tree or somewhere, and naturally ferment to produce alcohol. Perhaps humans, who had the ability to break down alcohol inherited from apes, noticed this and sipped it. It is possible that this was the origin of alcohol consumption.

The four food revolutions that shaped new flavors

── As we are now talking about humans, please tell us more about the history of “shikohin” in regard to humans.

In your book “The Monkey-fication of Human Society,” you talk about how mankind has experienced four food revolutions which led to the development of language and social structures. The first revolution is the “transport of food” where humans began transporting food to safely share it with their clan. The second is the “meat revolution” where humans started consuming meat which was higher in calories and nutrition. The third revolution was “cooking food” where fire was used to cook meat and vegetables, and the fourth was the “agricultural and pastoral revolution” where people began growing their own food and keeping livestock. 

Through these four revolutions, humans were able to efficiently consume energy so they had more time for social activities. Do you think this “extra” time helped encourage the development of “shikohin”?

Yamagiwa: Perhaps so. I did not mention this in my book, but through the food revolutions, humans developed new flavors of foods.  

For example, when humans started using fire to cook meat, it made a big difference because it was now easier to consume the fatty sections of the meat. The fatty parts are rare and delicious. For hunter-gatherers, grilling meat with the fat sizzling down is the most luxurious dish, and some cultures have the custom of eating the internal fat of animals raw or slightly scalded. I’ve eaten it myself, and it’s very sweet and delicious.

Of course, fat is an important nutritional source, but it is very hard to digest. I think fat was like a “shikohin,” where the main purpose to consume it was to simply enjoy the texture and flavor. 

Furthermore, due to the agricultural and pastoral revolution, humans started to use seasonings like salt and sugar.  In hunter-gatherer societies, people consumed salt and sugar from natural plants and animals. Salt is found in animal organs and blood, and there are leaves in the lowlands of Africa that contain salt. Sugar is found in abundance in fruits.

However, in an agricultural society, humans did not eat as many wild plants and animals. At the same time, working in the fields and caring for livestock is strenuous labor that requires a higher consumption of salt and sugar. That is what led to adding seasonings like salt and sugar. 

How the agriculture and livestock revolution ruined our diet 

── So “added” flavors such as fat, salt, and sugar came about due to the food revolution. 

Yamagiwa: However, the agricultural and pastoral revolution actually made our diet more monotonous. Paradoxically, this was a big factor that led humans to seek “shikohin.” 

The diet of hunter-gatherers changed daily according to what animals and plants were available at the time. They consumed a wide variety of foods. However, in the European style agricultural society, they shifted to a diet where they ate mostly the same plants and livestock everyday. 

When daily diets become monotonous and boring, the ruling class begins to desire rare foods that can only be found in foreign lands. Because the Christian societies considered the oceans “home of the monsters,” they did not eat seafood. In the mountains there were only berries and mushrooms. Consequently, they were mostly limited to a simple diet of wheat, vegetables and meat from livestock. This is why, when the Age of Discovery started in the 15th century, the ruling class sought out rare delicacies from Asia, Central and South Americas, and Africa. 

For royalty and nobility, serving delicacies to guests was a manner of maintaining their prestige as a host. It was the equivalent to building a palace or wearing fancy clothes. Tea, for example, was originally only enjoyed by aristocrats. These luxurious tastes of aristocrats gradually spread to the common people, and “shikohin” gained popularity.

── So the agricultural and pastoral revolution of food removed variety from our diet and that led humans to seek out “shikohin”?

Yamagiwa: It’s important to note that consumption of “shikohin” existed before the agricultural revolution. This is illustrated by the Göbekli Tepe, the world’s oldest religious site in Turkey, which was discovered in the late 20th century. Built some 10 thousand years ago, there are no fields nearby, and it is clear that the temple was built by hunter-gatherers.

Until this discovery, the common belief was that the construction of large-scale structures required stockpiling of food and could only be carried out by agro-pastoralists. Also, it was believed that hunter-gatherers were animists and did not have a monotheistic “god.” Therefore, it was difficult to imagine why they would gather in the same place every day to construct such a building. 

The discovery of the Göbekli Tepe uprooted these common beliefs. So why did these hunter-gatherers build such a temple? One theory is that it was to make alcohol. About 20 kilometers away from the Göbekli Tepe, they discovered the remains of a wild wheat field. They say that the hunter-gatherers may have worked on the building in exchange for beer. 

There is a theory that the laborers for the construction of the ancient Egyptian pyramids were also compensated with beer. “Shikohin” that helps people relax may have been the source of motivation for the laborers. This may be the reason why people endured the hard physical labor necessary to make the construction of such buildings possible. 

Part 2 of 2 》“Foods for Enjoyment,” and creating bonds that transcend family. Interview with Primatologist Junichi Yamagiwa on “Shikohin” 

Translation: Sophia Swanson