by Ross Andersen: What science can tell us about how other creatures experience the world…
mid the human crush of Old Delhi, on the edge of a medieval bazaar, a red structure with cages on its roof rises three stories above the labyrinth of neon-lit stalls and narrow alleyways, its top floor emblazoned with two words: birds hospital.
On a hot day last spring, I removed my shoes at the hospital’s entrance and walked up to the second-floor lobby, where a clerk in his late 20s was processing patients. An older woman placed a shoebox before him and lifted off its lid, revealing a bloody white parakeet, the victim of a cat attack. The man in front of me in line held, in a small cage, a dove that had collided with a glass tower in the financial district. A girl no older than 7 came in behind me clutching, in her bare hands, a white hen with a slumped neck.
The hospital’s main ward is a narrow, 40-foot-long room with cages stacked four high along the walls and fans on the ceiling, their blades covered with grates, lest they ensnare a flapping wing. I strolled the room’s length, conducting a rough census. Many of the cages looked empty at first, but leaning closer, I’d find a bird, usually a pigeon, sitting back in the gloom.
Jains move through the world in this gentle way because they believe animals are conscious beings that experience, in varying degrees, emotions analogous to human desire, fear, pain, sorrow, and joy. This idea that animals are conscious was long unpopular in the West, but it has lately found favor among scientists who study animal cognition. And not just the obvious cases—primates, dogs, elephants, whales, and others. Scientists are now finding evidence of an inner life in alien-seeming creatures that evolved on ever-more-distant limbs of life’s tree. In recent years, it has become common to flip through a magazine like this one and read about an octopus using its tentacles to twist off a jar’s lid or squirt aquarium water into a postdoc’s face. For many scientists, the resonant mystery is no longer which animals are conscious, but which are not.
o aspect of our world is as mysterious as consciousness, the state of awareness that animates our every waking moment, the sense of being located in a body that exists within a larger world of color, sound, and touch, all of it filtered through our thoughts and imbued by emotion.
Even in a secular age, consciousness retains a mystical sheen. It is alternatively described as the last frontier of science, and as a kind of immaterial magic beyond science’s reckoning. David Chalmers, one of the world’s most respected philosophers on the subject, once told me that consciousness could be a fundamental feature of the universe, like space-time or energy. He said it might be tied to the diaphanous, indeterminate workings of the quantum world, or something nonphysical.
These metaphysical accounts are in play because scientists have yet to furnish a satisfactory explanation of consciousness. We know the body’s sensory systems beam information about the external world into our brain, where it’s processed, sequentially, by increasingly sophisticated neural layers. But we don’t know how those signals are integrated into a smooth, continuous world picture, a flow of moments experienced by a roving locus of attention—a “witness,” as Hindu philosophers call it.
There now appears to exist, alongside the human world, a whole universe of vivid animal experience. Scientists deserve credit for illuminating, if only partially, this new dimension of our reality. But they can’t tell us how to do right by the trillions of minds with which we share the Earth’s surface. That’s a philosophical problem, and like most philosophical problems, it will be with us for a long time to come.
Apart from Pythagoras and a few others, ancient Western philosophers did not hand down a rich tradition of thinking about animal consciousness. But Eastern thinkers have long been haunted by its implications—especially the Jains, who have taken animal consciousness seriously as a moral matter for nearly 3,000 years.
Many orthodox Jain beliefs do not stand up to scientific scrutiny. The faith does not enjoy privileged access to truth, mystical or otherwise. But as perhaps the world’s first culture to extend mercy to animals, the Jains pioneered a profound expansion of the human moral imagination. The places where they worship and tend to animals seemed, to me, like good places to contemplate the current frontier of animal-consciousness research.
At the bird hospital, I asked Singh whether any of his patients gave him trouble. He said that one refused to be fed by hand and sometimes drew blood when he tried to pick it up. He led me to another room to see the offending bird, an Indian crow whose feathers were record-groove black but for a sash of latte-colored plumage around its neck. The crow kept fanning one of its wings out. Light from a nearby window filtered through the feathers, as though the wing were a venetian blind. Singh told me it was broken.
“A few days after the crow arrived, it started using a special call when it wanted food,” Singh said. “None of the other birds do that.” The bird’s call was not an entirely unique case of bird-to-human communication. A grey parrot once amassed a 900-word vocabulary, and in India, a few have been trained to recite the Vedic mantras. But birds have only rarely assembled verbal symbols into their own, original proto-sentences. And, of course, none has declared itself conscious.
That’s too bad, because philosophers tend to regard such statements as the best possible evidence of another being’s consciousness, even among humans. Without one, no matter how long I stared into the crow’s black pupil, wishing I could see into the phantasmagoria of its mind, I could never really know whether it was conscious. I’d have to be content with circumstantial evidence.
In Japan, one crow population uses traffic to crack open walnuts: The crows drop a nut in front of cars at intersections, and then when the light turns red, they swoop in to scoop up the exposed flesh.
Crows have an unusually large brain for their size, and their neurons are packed densely relative to other animals’. Neuroscientists can measure the computational complexity of brain activity, but no brain scan has yet revealed a precise neural signature of consciousness. And so it’s difficult to make a knockdown argument that a particular animal is conscious based strictly on its neuroanatomy. It is suggestive, though, when an animal’s brain closely resembles ours, as is the case with primates, the first animals to be knighted with consciousness by something approaching a scientific consensus.
As Singh and I talked, the crow grew bored with us and turned back to the window, as though to inspect its faint reflection. In 2008, a magpie—a member of crows’ extended family of corvids, or “feathered apes”—became the first non-mammal to pass the “mirror test.” The magpie’s neck was marked with a bright dot in a place that could be seen only in a mirror. When the magpie caught sight of its reflection, it immediately tried to check its neck.
The day after I visited the bird hospital, I left Delhi by car, on a road that follows the Yamuna River south and east, away from its icy source among the serrated ridges of the Himalayas. Delhi’s sewage has blackened long stretches of the Yamuna, making it one of the world’s most polluted rivers. From the road, I could see plastic bottles floating on its surface. In India, where rivers have a special place in the spiritual imagination, this is a metaphysical defilement.
Millions of fish once swam in the Yamuna River, before it was desecrated by the human technosphere, which now reaches into nearly every body of water on Earth. Even the deepest point in the ocean is littered with trash: A grocery bag was recently seen drifting along the bottom of the Mariana Trench.
We last swam in the same gene pool with the animals that evolved into fish about 460 million years ago, more than 100 million years before we split from birds. The notion that we are kin across this expanse of time has proved too radical for some, which is one reason the ever-changing universe described by Darwin has been slow to lodge in the collective human consciousness. And yet, our hands are converted fins, our hiccups the relics of gill-breathing.
Scientists have sometimes seemed to judge fish for their refusal to join our exodus out of the water and into the atmosphere’s more ethereal realm of gases. Their inability to see far in their murky environment is sometimes thought to be a cognitive impairment. But new evidence indicates that fish have minds rich with memories; some are able to recall associations from more than 10 days earlier.
Fish pain is something different from our own pain. In the elaborate mirrored hall that is human consciousness, pain takes on existential dimensions. Because we know that death looms, and grieve for the loss of richly imagined futures, it’s tempting to imagine that our pain is the most profound of all suffering. But we would do well to remember that our perspective can make our pain easier to bear, if only by giving it an expiration date. When we pull a less cognitively blessed fish up from the pressured depths too quickly, and barometric trauma fills its bloodstream with tissue-burning acid, its on-deck thrashing might be a silent scream, born of the fish’s belief that it has entered a permanent state of extreme suffering.
The Jains tell a story about Neminath, a man from deep antiquity who is said to have been sensitive to the distress calls of other animals. He developed his unusual fondness for animals while tending cattle in pastures on the banks of the Yamuna River, in his home village of Shauripur, which I reached four hours after leaving Delhi.
This moment transformed Neminath. Some versions of this story say he freed the surviving animals, including a fish that he carried, in his hands, back to the river. Others say he fled. All agree that he renounced his former life. Rather than marry his bride, he set out for Girnar, a sacred mountain in Gujarat, 40 miles from the Arabian Sea.
My own ascent up Girnar began before dawn. It followed the usual topography of enlightenment. I was to climb 7,000 steps, all built into the mountain, by nine in the morning, so as not to be late for a ritual at an ancient temple near the peak.
The trail was only 50 miles from Gir National Park, where, the day before, I’d seen two Asiatic lions, nearly indistinguishable cousins of Africa’s lions. Once the region’s apex predator, the Asiatic lion almost went extinct during the British empire’s colonization of India, when no viceroy could visit a maharaja’s palace without a hunt in the local forest. Even today, the Asiatic lion still ranks among the rarest of the large feline predators, rarer even than its neighbor to the north, the snow leopard, which is so scarce that a glimpse of one padding down a jagged Himalayan crag is said to consummate a spiritual pilgrimage.
I did my best to put the lions, which have recently expanded to Girnar’s forests, out of my mind as I passed small huts and tents in the dark, at the trail’s base. Daylight brought langur monkeys onto the trailside boulders. One watched a vendor set up his stall to offer food and water to passing Jain pilgrims. The monkey waited until the man’s back was turned, at which point he scampered in to grab a banana. In Gir National Park, I’d seen deer using these monkeys as a treetop surveillance system. The monkeys sat high in the trees, keeping watch for leopards and lions, which blend into the woodland’s pre-monsoon palette of amber and gold. Monkeys that spotted a stalking cat let out a specific call. Deer weren’t the only ones that recognized and used these calls; the lion tracker who had been with me in the park did too.
Lab-bound honeybees can learn to recognize abstract concepts, including “similar to,” “different from,” and “zero.”
Wasps, like bees and ants, are hymenopterans, an order of animals that displays strikingly sophisticated behaviors. Ants build body-to-body bridges that allow whole colonies to cross gaps in their terrain. Lab-bound honeybees can learn to recognize abstract concepts, including “similar to,” “different from,” and “zero.” Honeybees also learn from one another. If one picks up a novel nectar-extraction technique, surrounding bees may mimic the behavior, causing it to cascade across the colony, or even through generations.
In one experiment, honeybees were attracted to a boat at the center of a lake, which scientists had stocked with sugar water. When the bees flew back to the hive, they communicated the boat’s location with waggle dances. The hive’s other bees would usually set out immediately for a newly revealed nectar lode. But in this case, they stayed put, as though they’d consulted a mental map and dismissed the possibility of flowers in the middle of a lake. Other scientists were not able to replicate this result, but different experiments suggest that bees are capable of consulting a mental map in this way.
Andrew Barron, a neuroscientist from Macquarie University, in Australia, has spent the past decade identifying fine neural structures in honeybee brains. He thinks structures in the bee brain integrate spatial information in a way that is analogous to processes in the human midbrain. That may sound surprising, given that the honeybee brain contains only 1 million neurons to our brains’ 85 billion, but artificial-intelligence research tells us that complex tasks can sometimes be executed by relatively simple neuronal circuits. Fruit flies have only 250,000 neurons, and they too display complex behaviors. In lab experiments, when faced with dim mating prospects, some seek out alcohol, the consciousness-altering substance that’s available to them in nature in broken-open, fermenting fruit.
Many invertebrate lineages never developed anything beyond a rudimentary nervous system, a network of neurons dispersed evenly through a wormlike form. But more than half a billion years ago, natural selection began to shape other squirming blobs into arthropods with distinct appendages and newly specialized sensory organs, which they used to achieve liberation from a drifting life of stimulus and response.
The first animals to direct themselves through three-dimensional space would have encountered a new set of problems whose solution may have been the evolution of consciousness. Take the black wasp. As it hovered above the bougainvillea’s tissue-thin petals, a great deal of information—sunlight, sound vibrations, floral scents—rushed into its fibrous exoskull. But these information streams arrived in its brain at different times. To form an accurate and continuous account of the external world, the wasp needed to sync these signals. And it needed to correct any errors introduced by its own movements, a difficult trick given that some of its sensors are mounted on body parts that are themselves mobile, not least its swiveling head.
If one of the wasp’s aquatic ancestors experienced Earth’s first consciousness, it would have been nothing like our own.
The neuroscientist Björn Merker has suggested that early animal brains solved these problems by generating an internal model of the world, with an avatar of the body at its center. Merker says that consciousness is just the multisensory view from inside this model. The syncing processes and the jangle and noise from our mobile bodies are all missing from this conscious view—some invisible, algorithmic Stanley Kubrick seems to edit them out. Nor do we experience the mechanisms that convert our desires into movements. When I wished to begin hiking up the mountain again, I would simply set off, without thinking about the individual muscle contractions that each step required. When a wasp flies, it is probably not aware of its every wing beat. It may simply will itself through space.
When the monk arrived at the wall where I was resting, the wasp flew away, rising up toward the sun until I lost it in the light. The monk was wearing a white mask like those that some Jains wear to avoid inhaling insects and other tiny creatures. I nodded to him as he passed, and lay back against the warm stone of the mountain.
The monk was a white dot some six switchbacks up by the time I hopped off the wall and continued the climb, my legs stiffened by the break. I reached the entrance to the temple complex with only 15 minutes to spare. Its marble courtyard shone brilliant white, as though bleached by the mountain sun.
It was here on this mountain that Neminath is said to have achieved a state of total, unimpeded consciousness, with perceptual access to the entire universe, including every kind of animal mind. Jains believe that humans are special because, in our natural state, we are nearest to this experience of enlightenment. Among Earth’s creatures, no other finds it so easy to see into the consciousness of a fellow being.
The pilgrims started singing, first in a low hum and then steadily louder. One wheeled a giant drum next to the tunnel’s entrance and struck it with a dark mallet. Two others bashed cymbals together. Men and women walked in from opposite doors, converging, in two lines, on either side of the tunnel. A woman wearing an orange sari and a gold crown crossed in front of Neminath, lifted a vessel over his black-marble head, and poured out a mixture of milk and blessed water. When she finished, a white-robed man from the other line did the same.
The singing grew louder until it verged on ecstatic. The pilgrims raised their arms and clapped overhead, faster and faster. A climax seemed to loom, but then it all dropped away. The drums and the bells and the cymbals went quiet, leaving a clear sonic space that was filled by a final blow on a conch.
The shell’s low note was long and clean. It rang out of the temple and over the ancient peaks. As it trailed off, I wondered whether, in the centuries to come, this place might become something more than a Jain house of worship. Maybe it will become a place to mark a moment in human history, when we awakened from the dream that we are the only minds that nature brought into being. Maybe people will come here from all corners of the Earth to pay their respects to Neminath, who is, after all, only a stand-in for whoever it was who first heard animal screams and understood their meaning.