They look so "alien," but octopuses feel and remember pain like we do. We can track their emotional reactions. But their deeper feelings are a mystery.
Octopuses have three hearts and taste with their suckersImage: Britta Pedersen/dpa-Zentralbild/picture alliance
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Octavia, an octopus at the New England Aquarium in Boston, was old and dying. She had been moved from her display tank to a quieter, dark place that resembled an octopus' den. That's where the animals go to in the wild when they are nearing the end of their lives.
Her friend, Sy Montgomery, wanted to say goodbye.
The author and naturalist had known Octavia for several years. Montgomery had fed Octavia fish and played with her countless times. It was part of Montgomery's research for her 2015 book The Soul of an Octopus. Montgomery describes the animal's remarkable intelligence. She had befriended four octopuses (yes, that's the correct plural) with very different personalities.
Montgomery with an octopus (not Octavia) at the New England AquariumImage: New England Aquarium
When DW spoke with Montgomery, she recalled the last time she saw Octavia.
"She was sick, she was old and she was clearly dying," Montgomery said. "I opened the tank and she floated to the top to see me. And she was not hungry ― I handed her a fish and she just took it and put it aside. She made the effort to come up from the bottom of that tank to see me and to touch me. She extended her suckers to me and looked me in the face and held me for minutes."
That was after a period of 10 months during which Octavia had been down in her den, all on her own. She hadn't seen Montgomery or other people. For an animal that only lives three to five years, "10 months is decades," Montgomery said.
Soon after that Octavia passed away.
Emotions — not just reflex reactions
Their last goodbye was one of many interactions that Montgomery has had with octopuses that make her certain they have emotions. Her take is based on personal experiences, anecdotal evidence. But Montgomery isn't alone in her assessment.
There is a consensus in the field of animal sentience that octopuses are conscious beings — that they can feel pain and actively try to avoid it.
Kristin Andrews and Frans de Waal posit in a new report published in the journal Science that many animals, including cephalopods such as octopuses, feel pain . But they don't just react reflexively, like a child pulling away their hand from a hot stove. That type of reaction is known as nociception.
Octopuses display reactions that go far beyond that, say Andrews and de Waal, citing research from the past 20 years.
Octopuses can change their color and blend in with the environmentImage: Jutta Kirchner/Wiener Haus des Meeres/dpa/picture alliance
"Nociception does not necessarily reach the central nervous system and consciousness," they write in the Science article — that means the animal may want to avoid pain, but that this pain doesn't come with any associated feeling.
Octopuses, however, have shown that they avoid places where they previously experienced negative stimuli, even if they are free of pain in that very moment.
That, Andrews and de Waal write, is because they remember the pain they felt there, processed it and noted it as something they want to avoid. They feel a memory of pain.
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The difference between emotions and feelings
When researchers look at the inner lives of animals, they distinguish between emotions and feelings.
Emotions, write Andrews and de Waal, are "measurable physiological and/or neural states that are often reflected in behavior."
That includes increased body temperature, increased neurotransmitter and hormone activity or an animal's avoiding a place where a scientist poked it with a stick the other day.
Feelings, on the other hand, happen at a deeper level than emotions.
Human animals often share their feelings verbally. We say things like "I'm so happy!" or "That makes me really angry."
People can't communicate with other animals on that level. So, it's impossible for us to know exactly what non-human animals feel. But that doesn't mean they don't feel anything.
Speaking to DW, Andrews said "scientists should accept the feelings-side of emotions for animals, just like we do for humans. The 'yay!' of joy, the crushing, heavy despair of sadness. Feelings of pain, feelings of pleasure or of sun on your skin."
"We can't measure that in animals. But we can't measure it in humans either," said Andrews, the Research Chair in Animal Minds at York University in Toronto, Canada.
Scuba divers like filmmaker Craig Foster say octopuses are highly curious creaturesImage: Netflix/Everett Collection/picture alliance
Montgomery makes the same point. Sure, she doesn't know what feelings are at play when an octopus comes up to the water's surface to touch her gently. But do we ever have that knowledge about another living creature, she asks.
"I don't know what octopuses feel in their hearts," Montgomery said. "But I also don't know what my husband truly feels or whether happiness for him feels the same as happiness feels for me."
Important step for animal welfare
The UK has taken a step towards recognizing octopuses and their relatives as sentient — as their being conscious, with feelings and memories of pain.
Cephalopod molluscs, like octopuses, and decapod crustaceans, like crabs, lobsters and crayfish, are included in a new animal welfare law that is going through the UK parliament right now.
Jonathan Birch, an associate professor at the London School of Economics, led a team that looked at more than 300 studies before advising the UK government on the law.
If the UK's new animal welfare law is passed, crayfish, octopuses and their relatives will enjoy higher levels of protectionImage: Gottfried Czepluch/imago images
"The evidence tilted towards the animals being sentient," Birch said. "We recommended the inclusion of all of these animals in the scope of the animal welfare law. But the evidence was particularly strong for octopuses."
Birch says it's human to find it hard to empathize with animals like crayfish or octopuses, "because they look so different from us and they seem so alien."
"But that doesn't mean there's nothing there to empathize with, it doesn't mean they don't have feelings," he said. "We've got to be led by the evidence on this."
Edited by: Zulfikar Abbany
Of bird brains and herd mind — intelligence in the animal world
They calculate, distinguish languages and recognize themselves in the mirror. From pigeons to dolphins, we take a journey through the remarkable congitive skills of creatures far and wide.
Image: Britta Pedersen/dpa/picture alliance
Bird brain?
Scorned as 'rats of the air,' pigeons aren't famed for their erudition. Yet studies have shown these birdbrains can learn to read and even recognize misspelled words, pick a Monet from Picasso, and can be speedier multitaskers than humans. They may be far smaller than ours, but pigeons' brains boast six times as many nerve cells per cubic millimeter.
Image: Rahmat Gul/AP/picture alliance
What do we mean by intelligence?
When scientists talk about intelligence, they generally mean the ability to solve problems and recognize connections. Animals that solve problems by transferring previous experiences to come up with creative solutions are considered pretty smart. Planning ahead is also seen as advanced-level stuff in the animal world.
Corvids are as smart as primates — at least when it comes to finding food hidden in the shell game. They can also count, use tools and act strategically. If they're watched while hiding food, they'll come back and move it to a safer location once they are confident no one's looking. Ravens even recognize themselves in the mirror, which may indicate a degree of self-awareness.
Image: Remy de la Mauviniere/AP Photo/picture alliance
What does a fish see in the mirror?
Even fish can also recognize their reflections, but its unclear how self-aware they are. Tiny cleaner wrasses try to fight with their mirror images, then appear to test them by performing tricks like swimming upside down. Finally, they used the mirrors to scrub away marks scientists have applied to body parts they wouldn’t otherwise be able to see. Perhaps they just get how mirrors work.
Image: Frank Schneider/imagebroker/imago images
Is sealife stupider?
We don’t tend to think of fish among the smartest beasts. That might have to do with the less stimulating environment under water. A recent study posited that more complex environments on land mean animals are more likely to develop to complex strategies and planning abilities to navigate them, while marine life can rely more heavily on a pre-programmed set of responses.
Image: Reinhard Dirscherl/OceanPhoto/imago
Eight times the brain?
The subaquatic world isn't devoid of intelligent life though. The octopus confounds human prejudice that the smartest animals are those most like us. With a donut-shaped brain and lots of neurons in each of its eight dexterous arms, an octopus can use tools, solve complex tasks and recognize different people. Hunting in the varied terrain of reefs could be one factor in its unusual intelligence.
Dolphins, highly social, communicative and playful, have long been lauded among the wisest of beasts. They even appear to have given names, with individual animals identifying by a unique whistle. Yet some scientists claim dolphin intelligence is overrated: While the cetaceans do have large brains for their size, a lot of this bulk is just used to keep the nervous center warm.
Image: Augusto Leandro Stanzani/Ardea/imago images
Clever swine
It might make meat-eaters a little uncomfortable about their sausages, but pigs outsmart dogs on some intelligence tests. They can learn commands, respond to individual names and understand complex interactions of cause and effect. Taught to operate a joystick, pigs can understand the abstract relationship between the device's movement and the cursor on the screen.
Image: Lightpoet/Panthermedia/imago images
Cats or dogs?
Dog lovers and cat lovers have long argued over which of our companions is the smartest. Dogs can distinguish between different human languages, identify multiple objects by name and cooperate with human herders in complicated tasks. But comparisons are difficult. While dogs throw themselves into human games with a gleeful will to please, cats have zero interest in intelligence tests.
Image: Nano Calvo/VWPics/imago images
Knowing your enemy
Elephants are thought to score highly on emotional intelligence, being an unusually empathic species. Elephants in Amboseli National Park in Kenya have also been shown to differentiate the threat from different people, acting defensively or fleeing when they see, or hear the voices of, Massai men who sometimes hunt them, yet remaining calm when members of Kamba farming communities approach.
Image: R. de Haas/AGAMI/blickwinkel/picture alliance
Herd mind
Along with complex environments, sociability is thought to foster the evolution of intelligence. Like dogs, horses have lived with us for thousands of years, so it's no surprise they’ve read their human companions. Horses can tell friendly human faces from hostile ones, much as other herd animals, like goats, can judge the emotional state of members of their own species from their bleating.
Image: Julia Christe fStop Images/imago images
Smart — by whose standards?
If horses seem smarter than goats, perhaps that's partly because we’re more impressed by abilities that mirror our own. Studies tend to assess intelligence in human terms, says primatologist Frans de Waal: 'We humans have always based our definition of intelligence on the ability to count, for example. But for many animals, being able to count is of no use in their environment.'
Image: Jochen Tack/imago
Humans — the pinnacle of social intelligence?
Famously, we share more than 98% of our DNA with chimps. Humans' brain-to-body weight ratio is three times that of chimps. But the real difference is in our ability to learn from one another, passing on knowledge, refining, expanding and building on ideas and creating complex, ever-evolving cultures.
