Bees play by rolling wooden balls – apparently for fun. The cleaner wrasse appears to recognize its own face in an underwater mirror. Octopuses appear to respond to anesthetics and will avoid environments where they are likely to have experienced pain.
All three of these discoveries have been made in the past five years – indications that the more scientists test animals, the more they discover that many species have inner lives and are conscious. A surprising range of creatures have demonstrated conscious thoughts or experiences, including insects, fish, and some crustaceans.
That has prompted a group of top researchers in animal cognition to publish a new statement that they hope will change the way scientists and society view – and care for – animals.
Nearly forty researchers signed the ‘New York Declaration on Animal Consciousness’, which was presented for the first time at a conference at New York University on Friday morning. It marks a pivotal moment, as a flood of research into animal cognition collides with debates over how different species should be treated.
The statement says there is “strong scientific support” that birds and mammals have conscious experiences, and a “realistic possibility” of consciousness for all vertebrates – including reptiles, amphibians and fish. That possibility extends to many backboneless creatures, such as insects, decapod crustaceans (including crabs and lobsters), and cephalopod molluscs, such as squid, octopus, and squid.
“If there is a realistic possibility of conscious experience in an animal, it is irresponsible to ignore that possibility in decisions affecting that animal,” the statement said. “We need to consider welfare risks and use the evidence to inform our responses to these risks.”
Jonathan Birch, professor of philosophy at the London School of Economics and principal investigator of the Foundations of Animal Sentience project, is one of the signatories of the statement. While many scientists in the past assumed questions about animal consciousness were unanswerable, he says, the statement shows his field is moving in a new direction.
“This has been a very exciting ten years for the study of animal minds,” Birch said. “People are daring to go there in a way they haven’t before and to entertain the possibility that animals like bees, octopuses and squid could have some form of conscious experience.”
From ‘automatic’ to conscious
There is no standard definition for animal sentience or consciousness, but in general the terms refer to the ability to have subjective experiences: to sense and map the outside world, to have the capacity for feelings such as joy or pain. In some cases it can mean that animals possess a level of self-awareness.
In that sense, the new explanation ignores years of orthodoxy in historical scholarship. In the 17th century, French philosopher René Descartes argued that animals were merely “material automatons” – without souls or consciousness.
Descartes believed that animals “cannot feel or suffer,” says Rajesh Reddy, assistant professor and director of the animal law program at Lewis & Clark College. “To feel compassion for them, or empathy for them, was somewhat foolish or anthropomorphizing.”
In the early 20th century, leading behavioral psychologists promoted the idea that science should study only observable behavior in animals, rather than emotions or subjective experiences. But starting in the 1960s, scientists began to reconsider their views. Research began to focus on animal cognition, mainly among other primates.
Birch said the new statement seeks to “crystallize a new emerging consensus that rejects the view from 100 years ago that we have no way to study these questions scientifically.”
A wave of recent findings underlies the new explanation. Scientists are developing new tests of cognition and trying out existing tests on a wider range of species, with some surprises.
Take, for example, the mirror mark test, which scientists sometimes use to see whether an animal recognizes itself.
In a series of studies, the cleaner wrasse seemed to pass the test.
The fish were placed in an aquarium with a covered mirror, to which they showed no unusual response. But after the cover was lifted, seven of the ten fish launched attacks on the mirror, indicating that they likely interpreted the image as a rival fish.
After a few days, the fish sat down and tried strange behavior in front of the mirror, such as swimming upside down, which had not been seen before in this species. Later, some seemed to spend an unusual amount of time in front of the mirror examining their bodies. Researchers then marked the fish with a brown spot under the skin, meant to resemble a parasite. Some fish tried to rub the stain off.
“The sequence of steps you could only imagine in an incredibly intelligent animal like a chimpanzee or a dolphin is happening in the cleaner wrasse,” Birch said. “No one in a million years expected small fish to pass this test.”
In other studies, researchers found that zebrafish showed signs of curiosity when new objects were introduced to their aquarium and that squid could remember things they saw or smelled. One experiment stressed crayfish by giving them an electric shock and then gave them anti-anxiety drugs used in humans. The drugs seemed to restore their usual behavior.
Birch said these experiments are part of an expansion of research into animal consciousness over the past 10 to 15 years.
“We can have a much broader canvas where we study it in a very wide range of animals and not just mammals and birds, but also invertebrates like octopuses and squids,” he said. “And even more and more people are talking about this idea in relation to insects.”
With more and more species showing these kinds of symptoms, Reddy says, researchers may soon have to completely reframe their line of inquiry: “Scientists are being forced to consider this bigger question – not which animals are conscious, but which animals are not. ?”
New legal horizons
Scientists’ changing understanding of animal sentience could impact U.S. law, which does not classify animals as sentient at the federal level, Reddy said. Instead, laws regarding animals focus primarily on their conservation, farming, or treatment by zoos, research labs, and pet stores.
“The law is a very slow-moving vehicle and really follows society’s views on a lot of these issues,” Reddy said. “This statement, and other ways to help the public realize that animals are not just biological automatons, could create a groundswell of support for increasing protections.”
State laws vary widely. Ten years ago, Oregon passed a law recognizing animals as sentient and capable of feeling pain, stress and fear, which Reddy says has formed the basis of progressive legal views in the state.
Meanwhile, Washington and California are among a number of states where lawmakers this year have considered bans on octopus farming, a species for which scientists have found strong evidence of sentience.
British law was recently changed to consider octopuses as living creatures, alongside crabs and lobsters.
“Once you recognize animals as sentient, the concept of humane slaughter starts to matter, and you have to make sure that the kinds of methods you use against them are also humane,” Birch said. “In the case of crabs and lobsters, there are quite inhumane methods, such as dropping them into pots of boiling water, that are used very often.”
This article was originally published on NBCNews.com