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Do Fish Suffer?

Speakers at a meeting on animal consciousness dive into a deep ethical debate

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Years ago I was surfcasting on an ocean beach and caught a big, beautiful striped bass. My daughter and son, who were 8 and 10, respectively, were nearby. I held the fish up and yelled, Look kids, I caught dinner! Skye, my daughter, burst into tears and pleaded with me to let the fish go.

I tried to josh her out of her mood, in vain. I assured her that I’d been catching fish like this since I was a boy, fish don’t really feel pain, they’re just fish, they’re like swimming machines. Skye was unconvinced. I said I would stick a knife into the fish’s brain now to put it out of its misery. Dumb move! Skye shrieked in horror and begged me not to kill the fish. By now, other people on the beach, attracted by the commotion, had gathered around the weeping girl and mean man.

This traumatic—for me!—scene came back to me when I attended “Animal Consciousness” at New York University last weekend. I’m trying to wrap up a book on the mind-body problem, so I really didn’t have the time to attend the meeting. But I couldn’t resist going, and now I can’t resist firing off a quick report. [See also my followup post, Jellyfish, Sexbots and the Solipsism Problem.]


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Philosopher David Chalmers, one of the conference organizers, kicked the meeting off by noting that many researchers are investigating whether non-human animals are conscious. If animals are capable of consciousness, he said, they can suffer, and that should matter to us.

Chalmers noted that in 2012 a group of prominent scientists issued the so-called Cambridge Declaration on Consciousness. It stated that “the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates.” Octopi are hot now. Research has shown them to be extremely clever, that’s why they’re mentioned in the Declaration.

Fish should be on included too, according to one speaker at the NYU conference, biologist Victoria Braithwaite. Fish are a lot smarter than we give them credit for, she said. Gobies who live in tidal pools get a sense of the local topography while the tide is high and they can swim freely. When the tide goes out, if they find themselves chased by a predator in one pool, they know in which direction to jump to escape to a nearby pool. Fish from different species have surprisingly complex relationships with each other, Brathwaite said, showing us a film of an adorable grouper and moray eel teaming up to hunt other fish.

Brathwaite, author of the 2010 book Do Fish Feel Pain?, has also investigated whether fish can suffer. She has injected irritating chemicals, such as vinegar and bee venom, under the skin of trout and other fish. Here’s how she describes her experiments in The Los Angeles Times:

“If you've ever felt the nip of vinegar on an open cut or the sting of a bee, you will recognize these feelings as painful. Well, fish find these naturally irritating chemicals unpleasant too. Their gills beat faster, and they rub the affected area on the walls of their tank, lose interest in food and have problems making decisions.”

When she gave the fish painkillers, their behavior returned to normal, just as that of a human would. Her research, she writes, “opens a can of worms -- so to speak -- and begs the question of where do we draw the line. Crustacean welfare? Slug welfare? And if not fish, why birds? Is there a biological basis for drawing a line?”

Psychologist Stuart Derbyshire, who spoke after Braithwaite, dumped cold water over her premise. He assured us that he had nothing against fish, but he doubted whether they feel pain in a way remotely analogous to ours, given how different their brains are. He asked us to note the pressure being exerted on our backsides by our chairs. Before he drew our attention to this sensation, we weren’t aware of it, right? Well, fish probably have this kind of sensation without awareness or comprehension, which means they don’t really “feel” pain or anything else.

Derbyshire took a beating during the Q&A. When asked if dogs feel pain, he said it depends on what you mean by “feel pain.” If forced to answer that simplistic question, he’d have to say no. Dumb move! An audience member held up an actual, living dog, which had been sitting in her lap. Someone had stepped on her dog’s paw earlier, she said, and it yelped. What was the dog feeling then? Derbyshire sighed and said he didn’t know.

I felt bad for Derbyshire. He seemed to be suffering. But I was glad when Braithwaite declared that it doesn't matter to her whether a dog or fish suffers in the way that humans do. What matters is whether they suffer at all, and she believes they do. The audience applauded.

This exchange set up a talk by philosopher Peter Singer, who jump-started the modern animal-rights movement with his 1975 book Animal Liberation. Singer credited Jeremy Bentham with correctly framing the question of animal rights two centuries ago. Bentham said that “the question is not, Can [animals] reason? nor, Can they talk? but, Can they suffer? Why should the law refuse its protection to any sensitive being?”

Determining whether creatures are conscious is hard, Singer acknowledged. But in a rebuke to Derbyshire, Singer said that suffering should not require “reflection” to be morally important. Someone asked Singer if it bothered him that Braithwaite’s experiments caused fish pain. No, said Singer, showing his utilitarian colors, because her research might help bring about regulations that alleviate the suffering of countless fish.

Singer has been worrying about fish rights for a while. In 2010 he wrote in The Guardian that “the evidence is now accumulating that commercial fishing inflicts an unimaginable amount of pain and suffering. We need to learn how to capture and kill wild fish humanely--or, if that is not possible, to find less cruel and more sustainable alternatives to eating them.”

By the way, sitting in the front row watching this debate was Thomas Nagel, author of the famous 1974 paper “What Is It Like to Be a Bat?

I’m a life-long catcher and eater of fish, so it was hard listening to Braithwaite and Singer dwell on fish pain. But it was hard listening to Derbyshire too. How the hell does he know that fish don’t suffer? He doesn’t, any more than Braithwaite or Singer know that they do. Singer said we should give fish the benefit of the doubt, and I’m inclined to agree. Am I going to stop eating fish, or fishing? Probably not, but when I do I’ll feel bad about it.

You may be wondering what happened to that striped bass all those years ago. I threw it back into the ocean. I don’t know if the fish felt joy, but my daughter certainly did.

Further Reading:

Jellyfish, Sexbots and the Solipsism Problem

CatCam Probes Philosophical Puzzle: What Is It Like to Be a Cat?

Is Consciousness Real?

The Mind–Body Problem, Scientific Regress and "Woo"

Is Scientific Materialism "Almost Certainly False"?

Dispatch from the Desert of Consciousness Research, Part 1

Can Integrated Information Theory Explain Consciousness?

World's Smartest Physicist Thinks Science Can't Crack Consciousness

Meta-post: Horgan Posts on Brain and Mind Science.