Do animals feel pain? Science author Ed Yong says that’s the wrong question

The little college in Maine where I studied always had a lobster bake to kick off the academic year. Over a thousand vivid red crabs served with butter, or for the squeamish and vegetarians, chicken, steak, or portobello mushrooms. Even though I had the lobster, I thought the squeamish had it right. It's difficult not to imagine what it could be like to end up in a pot of boiling water when you stare into the eyes of your meal.

It turns out that British biologists were responding to that question as I was eating. Twenty years of research has revealed that lobsters, hermit crabs, and related animals exhibit what appears to be pain. On the basis of their discoveries, laws have been established. Now, you cannot boil a lobster alive in Switzerland if you want to eat it. The only acceptable methods of cooking the crustacean are electric shock or a head knife.

To a lobster, though, what does pain even mean? That's a far tougher topic, as scientific writer Ed Yong notes in his most recent book. Animals perceive physical reality differently than humans do through odors, electromagnetic fields, and water currents, and these senses affect the environment they live in in fundamentally unfathomable ways. He claims that to visualize a beetle traveling on a leaf “is like setting foot upon an alien planet”.

The Pulitzer Prize winner's second book, An Immense World, is a journey across those worlds and a celebration of the strength of human empathy. I kept going back to the paintings depicting the suffering of animals after reading it. I mentioned to Yong early on in our chat that, of all the animal senses, pain was the one that most people had given thought to. He objected. He claims that the question is frequently reduced to: “Do they feel it or not? In some ways, that is a very boring question to ask. The more sensible question is: what kinds of pain do they feel?”

An Immense World therefore explores both the thoughts of animals as well as the extraordinary empathy of professionals attempting to view the world through their eyes.

“Scientists are people. Everyone I talked to has absolutely thought about ‘what is the world like to the creature that I study,’” according to Yong. “Whenever I ask, ‘what is it like to be an electric fish, or a bat,’ they have answers, and they have interesting answers. That kind of informs the book—their speculation and feats of imagination are both vital and very much part of the story.”

“That kind of subjective, imaginative stuff is not in [scientific] papers, because it runs counter to how a lot of scientists are trained to think about their work. It’s a bit woolier and emotional and speculative. And important! But it doesn’t appear in the scientific literature very much.”

Yong is impressed by the creative experiments that scientists have designed to enter a different sensory realm. Elephants froze in response to rumbles played via subterranean speakers, audio engineers remixing birdsong for finches and canaries, and star-nosed moles rubbing their incredibly sensitive facial tentacles over bits of plastic.

However, some of the initial discoveries into the vast variety of animal senses necessitated mutilating them, much to how neuroscientists have learned about the human brain by seeing what occurs when a stroke kills neurons. An Italian priest in the 18th century blinded bats before testing their ability to fly in what Yong calls “a series of cruel experiments”. He discovered that they would “blunder into objects” if he further deafened or gagged them. 

These gruesome studies served as the foundation for the studies that led to the discovery of echolocation in the middle of the 20th century, which in turn paved the way for investigations into other senses that humans can only conjure up: environments shaped by electric fields, magnetism, or leaf vibrations.

“It’s difficult when at least part of the body of knowledge that you are referring to comes through work that is hard to contemplate,” adds Yong. “There are some experiments that honestly I wish had never been done. But l benefit from the knowledge gained through that. And I think probably one of the most important questions for sensory biologists right now is to sort of weigh that out. How much is it worth it?” 

There are just two components to the human sense of pain. Nociceptors, which are nerves dispersed throughout the body and light up when cut, crushed, burned, or exposed to chemicals, are what power the physical component. The conscious perception of that "nociception" comes next. Nociception is "an old sense," according to Yong, that manifests in startlingly similar ways in everything from sea slugs to humans. But just because an animal's brain recognizes pain signals doesn't imply it necessarily experiences pain.

“A leech will writhe when pinched, but are those movements analogous to human suffering, or to an arm unconsciously pulling away from a hot pan?” Yong writes in the book.

The response appears to be yes at times. According to a 2003 research, trout given bee venom rocked from side to side, wiped their mouths on gravel, and disregarded new items for hours, indicating that they felt more than just a chemical reaction.

It might be challenging to consider what it would mean to experience pain in a different way since it bears such moral significance for people. As a result, Yong compares pain to color vision, which is both a physical and conscious sensation.

We can perceive the rainbow spectrum because, as Yong notes, our brain machinery is designed to quickly calculate light wavelengths. (Not to mention how language affects how well we can distinguish subtle color differences.) In contrast, a mantis shrimp has four times as many different types of wavelength-sensing receptors, yet it only seems to see the world in 12 hues, "like a child's coloring book," according to Yong.

Even when an animal feels pain, it may not show up in typical ways. Squid appear to be hypersensitive to touch and sense the shock of an injury throughout their entire body. On the other hand, naked mole rats don't appear to be sensitive to some painful stimuli. They didn't respond when researchers injected them with acid, exposed their skin to capsaicin, or exposed them to carbon dioxide levels that would make human eyes hurt. When burnt or poked, they did, however, flinch.

Thus, the same researchers who attempt to enter the thoughts of animals find themselves hurting the creatures. “A lot of the people I talked to who study how animals sense painful stimuli want to do that work to help those creatures, to inform their welfare, and how we might want to make moral ethical decisions about them,” Yong remarked. “But to do that, you also need to inflict pain on creatures.”

“How do you weigh up the need to get a statistically roIn a previous chapter, Yong writes. In other words, we are left with a very anthropocentric understanding of what it means to conserve nature since we prioritize pain over other senses.

The latter chapters of the book take a careful look at how human society is influencing animals' sensory lives. The focus isn't so much on pain as it is on how LED light and the continual rumbling of motorways alter the worlds of creatures that see, hear, and experience things differently than we do. “When we ask if animals can feel pain, we’re asking less about the animals themselves, and more about what we can do to them,” Yong writes in a previous chapter. In other words, we are left with a very anthropocentric understanding of what it means to conserve nature since we prioritize pain over other senses.

It takes incredible empathy and deep delight to put yourself in an animal's shoes. Is it enough, though, given the more noisy traffic and lighter nights? Even after we become aware of the suffering we inflict on other living things, we still fail to alter our conduct. When Yong asked the scientist who conducted the trout-bee venom study if she thought her catch felt pain, the response was nearly often "yes," she said. They continue to cast their lines. 

According to Yong, animals experience pain in a variety of ways in order to withstand the threats unique to their species. At least for the kind of pain they cause, humans are able to mitigate some of it, but it is insufficient. Understanding the environments that different species inhabit is necessary if we are to assist them survive the Anthropocene.