……most scientists now feel they can say with confidence that some animals process information and express emotions in ways that are accompanied by conscious mental experience. They agree that animals, from rats and mice to parrots and humpback whales, have complex mental capacities; that a few species have attributes once thought to be unique to people, such as the ability to give objects names and use tools; and that a handful of animals — primates, corvids (the crow family) and cetaceans (whales and dolphins) — have something close to what in humans is seen as culture, in that they develop distinctive ways of doing things which are passed down by imitation and example. No animals have all the attributes of human minds; but almost all the attributes of human minds are found in some animal or other.
The most common test of self-awareness is the ability to recognise yourself in a mirror. It implies you are seeing yourself as an individual, separate from other beings. The test was formally developed in 1970 by Gordon Gallup, an American psychologist, though its roots go back further; Darwin wrote about Jenny, an orang-utan, playing with a mirror and being “astonished beyond measure” by her reflection. Dr Gallup daubed an odourless mark on the face of his subjects and waited to see how they would react when they saw their reflection. If they touched the mark, it would seem they realised the image in the mirror was their own, not that of another animal. Most humans show this ability between the ages of one and two. Dr Gallup showed that chimpanzees have it, too. Since then, orang-utans, gorillas, elephants, dolphins and magpies have shown the same ability. Monkeys do not; nor do dogs, perhaps because dogs recognise each other by smell, so the test provides them with no useful information.
Philosophers call the ability to recognise that others have different aims and desires a “theory of mind”. Chimpanzees have this. Santino seemed to have understood that zookeepers would stop him throwing stones if they could. He therefore hid the weapons and inhibited his aggression: he was calm when collecting the stones, though agitated when throwing them. An understanding of the capabilities and interests of others also seems in evidence at the Centre for Great Apes, a sanctuary in Florida, where male chimpanzees living with Knuckles, a 16-year-old with cerebral palsy, do not subject him to their usual dominance displays. Chimps also understand that they can manipulate the beliefs of others; they frequently deceive each other in competition for food.
Another test of legal personhood is the ability to experience pleasure or pain — to feel emotions. This has often been taken as evidence of full sentience, which is why Descartes’s followers thought animals were unable to feel, as well as reason. Peter Singer, an Australian philosopher and doyen of “animal rights”, argues that, of all the emotions, suffering is especially significant because, if animals share this human capacity, people should give consideration to animal suffering as they do to that of their own kind.
Animals obviously show emotions such as fear. But this can be taken to be instinctual, similar to what happens when people cry out in pain. Behaviourists had no trouble with fear, seeing it as a conditioned reflex that they knew full well how to create. The real question is whether animals have feelings which involve some sort of mental experience. This is not easy. No one knows precisely what other people mean when they talk about their emotions; knowing what dumb beasts mean is almost impossible. That said, there are some revealing indications — most notably, evidence for what could be seen as compassion.
Some animals seem to display pity, or at least concern, for diseased and injured members of their group. Stronger chimps help weaker ones to cross roads in the wild. Elephants mourn their dead (see “The grieving elephant”). In a famous experiment, Hal Markowitz, later director of the San Francisco zoo, trained Diana monkeys to get food by putting a token in a slot. When the oldest female could not get the hang of it, a younger unrelated male put her tokens in the slot for her and stood back to let her eat.
There have also been observations of animals going out of their way to help creatures of a different species. In March 2008, Moko, a bottlenose dolphin, guided two pygmy sperm whales out of a maze of sandbars off the coast of New Zealand. The whales had seemed hopelessly disoriented and had stranded themselves four times. There are also well-attested cases of humpback whales rescuing seals from attack by killer whales and dolphins rescuing people from similar attacks. On the face of it, this sort of concern for others looks moral — or at least sentimental.
In a few examples the protecting animals have been seen to pay a price for their compassion. Iain Douglas-Hamilton, who studies elephants, describes a young female which had been so severely injured that she could only walk at a snail’s pace. The rest of her group kept pace with her to protect her from predators for 15 years, though this meant they could not forage so widely. As long ago as 1959, Russell Church of Brown University set up a test which allowed laboratory rats in half of a cage to get food by pressing a lever. The lever also delivered an electric shock to rats in the other half of the cage. When the first group realised that, they stopped pressing the lever, depriving themselves of food. In a similar test on rhesus monkeys reported in the American Journal of Psychiatry in 1964, one monkey stopped giving the signal for food for 12 days after witnessing another receive a shock.
……there will be some dimensions in which animal minds exceed humans. Take the example of Ayumu, a young chimpanzee who lives at the Primate Research Institute of the University of Kyoto. Researchers have been teaching Ayumu a memory task in which a random pattern of numbers appears fleetingly on a touchscreen before being covered by electronic squares. Ayumu has to touch the on-screen squares in the same order as the numbers hidden beneath them. Humans get this test right most of the time if there are five numbers and 500 milliseconds or so in which to study them. With nine numbers, or less time, the human success rate declines sharply. Show Ayumu nine numbers flashed up for just 60 milliseconds and he will nonchalantly tap out the numbers in the right order with his knuckles.
There are humans with so called eidetic, or flash, memories who can do something similar — for chimps, though, this seems to be the norm. Is it an attribute that chimps have evolved since their last common ancestor with humans for some reason — or one that humans have lost over the same period of time? More deeply, how might it change what it is for a chimp to have a mind? How different is having minds in a society where everyone remembers such things? Animals might well think in ways that humans cannot yet decipher because they are too different from the ways humans think — adapted to sensory and mental realms utterly unlike that of the human, perhaps realms that have not spurred a need for language. There is, for example, no doubt that octopuses are intelligent; they are ferociously good problem solvers. But can scientists begin to imagine how an octopus might think and feel?
All that said, the third general truth seems to be that there is a link between mind and society which animals display. The wild animals with the highest levels of cognition (primates, cetaceans, elephants, parrots) are, like people, long-lived species that live in complex societies, in which knowledge, social interaction and communication are at a premium. It seems reasonable to speculate that their minds — like human ones — may well have evolved in response to their social environment (see “The lonely orca”). And this may be what allows minds on the two sides of the inter-species gulf to bridge it.
Off Laguna, in southern Brazil, people and bottlenose dolphins have fished together for generations. The dolphins swim towards the beach, driving mullet towards the fishermen. The men wait for a signal from the dolphins — a distinctive dive — before throwing their nets. The dolphins are in charge, initiating the herding and giving the vital signal, though only some do this. The people must learn which dolphins will herd the fish and pay close attention to the signal, or the fishing will fail. Both groups of mammals must learn the necessary skills. Among the humans, these are passed down from father to son; among the dolphins, from mother to calf. In this example, how much do the species differ?