Animal Emotions and Intelligence: What the Science Really Shows

Everything You Think You Know About Animals Is Wrong

Not long ago, textbooks drew a neat line between people and every other creature. Only humans, the story went, felt empathy, made tools, recognised themselves in a mirror or understood death. Decades of field work and laboratory studies have rubbed that line out in many places. Rats will free a trapped companion even when chocolate is on offer, hens react physically when their chicks are distressed, a crow has bent wire into a hook, and several species respond to a mirror in ways that suggest a sense of self.

The honest picture is more interesting than the viral version, though. Abilities vary hugely between species, some celebrated findings have been challenged, and scientists still argue about how to read animal behaviour without projecting our own feelings onto it. Below is what the research actually shows, where the evidence is thin, and why it matters for the way we live alongside other animals.

The old list of things only humans can do

For much of the twentieth century, human uniqueness rested on a handful of traits: language, tool making, self-awareness, moral feeling and a sense of past and future. The field now called cognitive ethology, the study of how animals think, feel and live socially, set out to test each one by watching animals in the wild and designing careful experiments in captivity.

The idea that our minds sit on a continuum with other species is not new. Charles Darwin argued in The Descent of Man (1871) that "the difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind." What has changed is the amount of evidence.

Empathy in rats, mice and chickens

The best-known modern experiment comes from the University of Chicago. In a 2011 paper in Science, Inbal Ben-Ami Bartal, Jean Decety and Peggy Mason placed a free rat next to a cagemate held in a small restraining tube. Over several sessions, most free rats learned to nudge the door open, and once they had worked it out they did so almost straight away. They ignored a stuffed toy rat in the same tube, so the behaviour was aimed at a living companion.

The striking test came next. Given a choice between a tube holding chocolate chips and one holding their cagemate, the rats were about as likely to free the friend first, and they usually left some chocolate for it. Mason summed it up plainly: "He can hog the entire chocolate stash if he wanted to, and he does not."

Mice show a related sensitivity. A 2006 study from McGill University reported that mice reacted more strongly to a painful stimulus when a familiar cagemate was in pain at the same time, a kind of emotional contagion. Chickens, often treated as the least valued farm animal, surprised researchers at the University of Bristol in 2011. When chicks received a mildly unpleasant puff of air, their mothers became more alert, preened less, called to the chicks more often and showed a faster heart rate and a drop in eye temperature, a recognised stress signal.

Older research pointed the same way, though by methods few labs would accept today. Studies in the late 1950s and 1960s reportedly found that rats, and later rhesus monkeys, would stop pulling a food lever when it also delivered a shock to a companion, with one monkey said to have gone without food for twelve days.

Rescues, kindness and unlikely friendships

Some of the most moving accounts involve great apes. On 16 August 1996, a three-year-old boy fell about 7 metres into the gorilla enclosure at Brookfield Zoo near Chicago. Binti Jua, a female western lowland gorilla with her 17-month-old daughter Koola clinging to her back, walked to the unconscious child, cradled him and carried him towards the keepers' door.

Chimpanzees at the Sanaga-Yong rescue centre in Cameroon watch as the body of Dorothy, an older female, is carried away. The photograph by Monica Szczupider was widely published in 2009 and helped bring animal grief into public debate.

Primatologist Frans de Waal described a bonobo named Kuni at Twycross Zoo in England who found a stunned starling. She climbed the tallest tree in her enclosure, opened the bird's wings and tried to launch it into the air. The rescue failed, but she then guarded the bird from a curious youngster. The philosopher Mark Rowlands has used stories like these to argue that some animals act for moral reasons, even if they cannot explain those reasons.

Ethologist Marc Bekoff, writing with philosopher Jessica Pierce in Wild Justice (2009), collected many more examples. Among them: an older elephant chasing off a young male who had knocked over an injured female, a Diana monkey helping a female who could not work a token machine, a fruit bat apparently guiding another through birth, and a cat called Libby who reportedly led her blind and deaf dog companion, Cashew, around obstacles.

Cross-species friendships, like the pair in this widely shared photo (photographer unknown), are most common in captivity, where animals are fed and safe, but they show how flexible social bonds can be.

Friendships across species fall into the same category. Sanctuaries and zoos have documented bonds between a cheetah and a retriever, a dog and a deer, and a goat and a horse. In 2013 researchers working off the Azores reported a group of sperm whales travelling with an adult bottlenose dolphin that had a spinal deformity, a rare case of an apparent long-term association between the two species in the wild.

Tools, memory and seeing yourself in a mirror

In 2002 a team at the University of Oxford led by Alex Kacelnik reported that Betty, a New Caledonian crow, had bent a straight piece of wire into a hook to lift a small bucket of food out of a tube. She did it nine times out of ten successful attempts, without being trained to.

Chimpanzees have their own headline result. At Kyoto University's Primate Research Institute, a young chimp named Ayumu learned to recall the positions of numbers flashed briefly on a touchscreen and outperformed university students on the task. Later researchers argued that the comparison was unfair because Ayumu had far more practice, so the safest reading is that chimpanzee working memory for this kind of task is at least very good, not that apes are smarter than people.

The mirror test, devised by psychologist Gordon Gallup in 1970, checks whether an animal uses its reflection to investigate a mark it cannot see directly. Chimpanzees pass most consistently. Bonobos, orangutans, some gorillas, bottlenose dolphins and at least one Asian elephant have also passed in published studies. A 2008 report that Eurasian magpies passed was not confirmed by a 2020 replication, a reminder that single studies can mislead. Critics also point out that the test favours animals that rely on sight; a dog that "fails" may simply care more about smell.

Language is the most contested area. Irene Pepperberg's African grey parrot Alex learned to label objects, colours and quantities, and Koko the gorilla used many signs, though researchers still disagree about how much grammar or understanding was involved. Other popular claims need a lighter touch. A 2013 study reported that dogs tend to line up roughly north to south when relieving themselves under calm magnetic conditions, but the idea that dogs "sense" when their owners are coming home has not stood up to controlled tests.

Footage filmed for a 2013 BBC documentary showed young dolphins handling pufferfish and then behaving oddly, which led to headlines about dolphins "getting high". Scientists say it is not clear whether the effect is intentional.

Grief and the awareness of death

Many people first meet the idea of animal grief through Jane Goodall's account of Flint, a young chimpanzee at Gombe in Tanzania. After his mother Flo died in 1972 he stopped eating, withdrew from the group and died within weeks.

Researchers from Kyoto University reported in 2010 that two chimpanzee mothers at Bossou in Guinea carried the bodies of their dead infants for weeks, in one case reportedly for more than two months, grooming them as the bodies dried out. Elephants are known to stand over the dead, touch the body with their trunks and return to bones. Scientists remain careful here: it is hard to separate mourning from curiosity or confusion, and the inner experience of another species cannot be measured directly.

Why scientists still urge caution

Sceptics are right that people tend to see human motives everywhere. In 1894 the psychologist C. Lloyd Morgan proposed what is now called Morgan's canon: do not explain behaviour with a higher mental faculty if a simpler one will do. Applied to the rat studies, a sceptic might say the free rat simply wanted to stop an unpleasant noise.

Rowlands answers that this misses the point. A person who cannot bear to hear someone screaming is not showing a lack of empathy; the distress is the empathy.

In July 2012 a group of neuroscientists at the University of Cambridge signed the Cambridge Declaration on Consciousness, written by Philip Low and edited by researchers including Christof Koch, Diana Reiss and Jaak Panksepp. It is a statement of scientific opinion, not an official ruling. It says the weight of evidence shows humans are not unique in possessing the brain systems that generate consciousness, and names all mammals and birds, along with many other creatures including octopuses.

What this means for how we treat animals

If many animals can feel fear, pain, attachment and loss, the way we farm, test on and entertain ourselves with them becomes a moral question rather than a technical one. Bekoff argues that cooperation and care are as much part of animal nature as competition, and turns a familiar insult on its head: "When people say, 'you're behaving like an animal,' it's actually a compliment."

It is sometimes said that the major religions simply license human domination of animals. The real picture is more mixed. Jewish law includes the principle of avoiding unnecessary suffering to animals, Islamic tradition records hadiths praising kindness to animals, and Christian writers from Francis of Assisi onward have stressed stewardship.

Law is slowly following the science. The European Union's Lisbon Treaty recognises animals as sentient beings, and New Zealand wrote animal sentience into its welfare law in 2015. Practical steps for individuals are simpler: learn to read the body language of the animals you live with, choose higher-welfare products where you can, support well-run sanctuaries and rescue groups, and treat wild animals as neighbours rather than entertainment.

None of this means a mouse is a small person. It means that the gap between us and other animals is narrower, and more varied, than we once assumed, and that curiosity and respect are better guides than certainty.

Sources: University of Chicago News: rats free trapped cagemates (2011); Wikipedia: Empathy in chickens; Wikipedia: Binti Jua; Wikipedia: New Caledonian crow; Wikipedia: Ayumu; Wikipedia: Mirror test; Wikipedia: Animal grief; Wikipedia: Cambridge Declaration on Consciousness. Topic originally covered by True Activist.

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