In July 1932, a rhesus monkey at the recently opened Chester Zoo was seen by visitors gnawing at a length of rope. After tying one end to a branch, he made the other into a noose. He put it over his head and jumped, dying instantly.



“Monkey commits suicide!” screamed newspaper headlines, while pictures showed the animal hanging, looking horribly human. It sparked a heated debate over whether it was deliberate, whether the monkey was depressed and whether animals should be kept in captivity. Yet no one really had a clue about the monkey’s state of mind.

Nearly a century on, we still struggle to unravel the emotional lives of animals. Distress in animals can be easier to spot than happiness but rarely can there be a subject where popular views are so far removed from scientific understanding. Most pet-owners are convinced that when a cat purrs or dog wags its tail it is expressing joy. Surely it would be arrogant and anthropocentric to assume that humans are the only happy animals on the planet?

Most scientists and philosophers, however, are far more cautious. This scientific approach has been articulated by Marian Stamp Dawkins, professor of animal behaviour at Oxford University, who specialises in the study of chickens and farm animal welfare. Animal behaviourists such as Stamp Dawkins do not deny the existence of animal consciousness but say that theories about it cannot be tested in the real world. Only observable behaviour and physiology can be studied scientifically and yet Stamp Dawkins has complained about a “rising tide of anthropomorphism”.

We certainly project human motivations on to animals in clumsy and unscientific ways, as shown by the story of Anne, an extremely well-travelled fiftysomething with gammy legs who has been up the Eiffel Tower and along Blackpool Beach. Anne was the last circus elephant in England and two years ago she was taken from the circus after her owners were convicted of animal cruelty: video footage showed a groom beating her. Anne was taken in by Longleat Safari Park, but when the elderly elephant arrived she began destroying the trees in her enclosure. “The anti-animals-in-captivity campaigners would probably say that’s because of the trauma she experienced in the circus,” says Longleat’s head vet, Jonathan Cracknell. “But Anne’s not a demonic animal, she’s an elephant – she enjoys smashing stuff up because she can.”

We have no scientific understanding of whether Anne is happier freed from the circus, but Cracknell has a clue – he travels the world treating traumatised captive animals for charities including Free the Bears and International Animal Rescue. Anne is physically crippled and, unusually for an elephant, does not enjoy the company of her peers – which may be a product of past trauma. But, says Cracknell: “She’s relatively unfazed by anything and she has good days and bad days from a point of view of emotion and play. She can be a right cheeky chappie – you can see moments when she is totally enjoying being herself.”

Vets tend not to be sentimental, but Cracknell says a certain amount of empathy goes with the job. “If you don’t think animals have emotions and don’t have the ability to enjoy as well as suffer, then you’re not the person to help rescue bears,” he says. “When you’re working in zoos and rehabilitation centres, you get a gut feeling about the behaviours you’re seeing – play, antics, animals interacting maliciously but also sometimes just because they are enjoying themselves. We see mammals behaving as individuals all of the time. Even the small ones – and not just mammals.”

The thrill of being alive

Cracknell has watched crows sliding down snowy hillsides in Scotland and then returning to do it again. He can’t see the “evolutionary benefit” of such behaviour. “They are just enjoying themselves for the thrill of being alive.” Recently, at Longleat, a macaque started swimming: it wasn’t hot, there was no apparent benefit of food, territory or hierarchy. “There’s no advantage to that animal learning to swim but it has.” Is pleasure, or even happiness, the answer?

Charles Darwin wrote about animal consciousness in 1872 but for most of the 20th century we showed little inclination to scientifically explore the inner lives of animals. In recent decades, animal behaviourists have studied pain and suffering in animals but positive emotions, such as happiness, have been neglected. This is partly because negative emotions are easier to detect: fear generally produces observable behaviour while stress, for instance, can be measured through the stress hormone cortisol.

Today, however, there is a growing field of animal happiness studies, although scientists prefer the term “positive emotions”. Here, it appears easier to prove that an animal is experiencing pleasure than happiness if happiness is defined as three processes: a physiological response to certain stimuli, an expression of that emotion, and an ability to reflect upon that emotion. Studies show rats, for example, can achieve the first two processes but there is no evidence of the third.

A rat may be able to “laugh”, however, according to Jaak Panksepp, an American psychobiologist and neuroscientist, who discovered that when a rat is tickled it makes ultrasonic chirps, associated with positive ratty experiences such as finding food or sex. For Jonathan Balcombe, author of Pleasurable Kingdom: Animals and the Nature of Feeling Good, this work is proof that rats “are not just conscious, cognitive but socially adept and mirthful”. Balcombe will next year launch Animal Sentience, the first journal dedicated to the study of animal feelings.

He argues that “new technology is allowing scientists to probe aspects of animal lives that weren’t available decades ago”. Scientists have trained dogs to undergo MRI and fMRI scans. Hungarian researchers recently found that dog brains reacted similarly to human brains when exposed to voices and emotionally charged sounds, such as crying and laughter. A US study showed that the scent of a dog’s guardian is more appealing than other scents, lighting up more reward centres in the brain. “Pleasure,” explains Balcombe, “is nature’s way of encouraging ‘good’ behaviours like finding food, shelter and procreation, which are very useful from an evolutionary perspective.” He’s willing to take a step further than many scientists: “If an animal is playing or laughing, it suggests to me an animal who is more than experiencing pleasure but can be happy.”

Balcombe has been criticised by Stamp Dawkins for making untestable anthropomorphic claims and zoologist Jules Howard, author of Sex on Earth, says it remains virtually impossible to detect even an apparently simple sensation, such as whether animals experience pleasure when having sex. “How would you tell if a dolphin is enjoying sex? You can’t get it in a CT scanner and rub its erection,” says Howard. “Masturbation is an interesting behaviour. There’s no reason to do it unless it just feels a bit nice, but there’s not enough people studying that kind of thing.” Even when scanning brains to detect activity that may denote pleasure, we can only really say it is showing the “hallmarks of happiness”, cautions Howard. Nevertheless, he accepts the logic that it would be amazing if we were the only species who could be happy.

An optimistic goat. Possibly. Photograph: Alamy

In Britain, some intriguing work on positive emotions in animals is being undertaken by Alan McElligott and Elodie Briefer of Queen Mary’s University, working with goats in a sanctuary in Kent. They trained the animals to discriminate between a location where there was a reward and one where there was none: the goats turned left along a corridor to obtain apples and carrots but if they turned right there was never any food. When the goats were exposed to ambiguous locations – corridors leading ahead rather than left or right – the scientists discovered a surprising result. Female goats who had suffered physical abuse before they arrived at the sanctuary were quicker to explore these uncertain options, where no reward was guaranteed, than well cared-for goats. The abuse survivors were more “optimistic” and the scientists suggested this was because they were more resilient to stress. Balcombe thinks this optimistic demeanour demonstrates goats’ capacity for “happiness” but McElligott is not so happy with that term.

“It’s important for scientists working on this to be really robust and not anthropomorphic in speculating on the data,” says McElligott. “If you go down the anthropomorphic route you lose credibility. If scientists want to write about something, it should be backed up by data. There’s a lot that we can say robustly about animals. I don’t need to go further than our current knowledge.”

Wild animals are so difficult to study that the science of animal happiness only really applies to domesticated animals. Are they different from wild animals? Studies have shown that domestication enables animals such as dogs to better interpret information that is coming from humans. If animal emotions are a product of animals living with humans, have we taught animals to be happy? Are domesticated animals becoming more human? Such questions are a leap too far for scientists. “I would never say that they are becoming more human,” says McElligott. In fact, he says, despite 10,000 years of domestication, goats turn feral within a generation if released into the wild.

The implications of animal happiness studies are profound. If scientists can map out the complexity of animal emotional lives, it becomes harder to subject them to factory farming, or confinement not conducive towards their “happiness”. While some may suspect that animal emotions are not studied widely because so many industries will lose money if we must rear “happy” animals, McElligott argues there is no conflict between better animal welfare and productivity: research shows that emotionally content animals put on weight more quickly and are less likely to succumb to physical ailments.

Many of those working in the field of animal happiness are motivated by a belief that animals have rights and their studies have big implications for meat-eaters. “If you can enjoy life, then death is harmful because you’re having a life cut short,” argues Balcombe. “There is a huge disconnect between our growing understanding of animals and how we continue to treat them.”

Globally we are eating more meat but its consumption is declining in the US, and Balcombe hopes it will continue to do so as we become more aware of the inner lives of animals. “Maybe I’m the abused goat,” says Balcombe, “but I am very encouraged by some of the trends that are emerging now in the US. Ultimately I’d like to see us applying the sorts of principles of respect and compassion to animals that we generally apply to our fellow humans.”

Patrick Barkham is the author of Badgerlands, published by Granta