They’re different from us, all right — we know that in our guts. But they’re also the same

How would you feel about marrying a chimpanzee? Horror, disgust, revulsion: I mean, they are not human, are they?

So, how would you feel about serving up a chimp for your Sunday dinner? Horror, disgust, revulsion: it would look and feel like cannibalism.

This is not a make-your-mind-up contradiction. The confusion is an unavoidable aspect of the relationship between humans and chimp.

They’re different from us, all right — we know that in our guts. But they’re also the same. They are closer to us than any other non-human life-form on the planet.

Last week, a revolutionary decision was made in a U.S. court: chimpanzees were acknowledged to have rights of their own.

It is the first time legal rights of any kind have ever been accorded to anything other than a human.

The story started in 2013, when an organisation called the Nonhuman Rights Project filed a lawsuit in the New York Supreme Court on behalf of four chimps kept for research by Stony Brook University. The eventual conclusion of Justice Barbara Jaffe was that they were not to be treated as property, but as legal persons.

Not as persons with full human rights, but as persons with a right not to be held in captivity and a right not to be owned.

The fact is that chimpanzees really are almost human. It’s a truth that humankind has tried to ignore ever since Charles Darwin declared in 1871 that humans were related to the apes of Africa.

Modern genetic studies have shown that this relationship is much closer than people thought. We have nearly 99 per cent of our genetic material in common.

And if that one-and-a-bit per cent is unquestionably significant, the rest of it takes a fair amount of thinking about. Chimpanzees are more closely related to us than to their — or should it be our — fellow apes, the gorillas and orang-utans.

It has been suggested that humans and chimpanzees belong not just in the same family, but in the same genus: in other words, the only correct way to understand the human connection to other species is to accept that humans are a species of chimpanzee . . . or chimp-anzees are a species of human.

And if that sounds fantastic, cast your mind back. Some statements made about race — statements that are shocking now — were once accepted as good sense: ‘There is a physical difference between the White and the Black races which I believe will forever forbid the two races living together on terms of social and political equality.’ That was Abraham Lincoln in 1858.

One more: ‘The mental constitution of the negro is . . . normally good-natured and cheerful, but subject to sudden fits of emotion and passion during which he is capable of performing acts of singular atrocity, impressionable, vain, but often exhibiting in the capacity of a servant a dog- like fidelity . . .’ That’s from Encyclopaedia Britannica 1911.

Last week, a revolutionary decision was made in a U.S. court: chimpanzees were acknowledged to have rights of their own. Above Kenuzy, a chimpanzee from Los Angeles, appears to laugh

The great primatologist Frans de Waal said of us humans: ‘We are apes in every way, from our long arms and tail-less bodies to our habits and temperament.’

A study published this week in the journal BMC Evolutionary Biology said that the many humans who suffer from lower back pain do so because their spines are more like those of chimpanzees than the spines of those people who don’t suffer from back pain.

In other words, some humans are less well adapted to walking upright than others because their spines are ‘statistically indistinguishable’ from those of chimps.

And we find many traits in chimps that are equally uncomfortable.

One chimp learned to use sign language

Take language. Washoe was a chimpanzee born in West Africa in 1965 and captured for use in the American space programme. She was brought up in an American family and taught sign language.

Experiments to teach chimps spoken language had all failed: they don’t have the physical equipment to make sufficiently varied sounds, but they communicate with body language in their wild daily lives.

Washoe acquired a vocabulary of 350 signs, and taught some of them to her adopted chimpanzee son Louis. On seeing a swan, she signed ‘water’ and then ‘bird’.

Washoe put together a near sentence when a doll was put in her drinking mug: ‘Baby in my cup.’ Another time she signed to her teacher: ‘You me out go.’ She received the answer: ‘OK, but put clothes on.’ Washoe immediately put on her jacket.

And, touchingly, one of her regular teachers suffered a miscarriage and was absent for some time. On her return, she signed to Washoe: ‘My baby died.’ Washoe signed back: ‘Cry.’ She then traced the track of a tear on her face. This is an astonishing bit of empathy: chimpanzees don’t weep.

A similar project involving a chimpanzee called Nim Chimpsky failed to get the same results. It was conducted with clinical rigour, without messy stuff like affection and with many changes of assistants.

A human child needs love to learn, as every parent knows. This failed experiment seems to prove that chimpanzees are no different.

They outperform humans in some computer games, in which snap decision making is required. In problem-solving tests, chimpanzees have invented all kinds of complex ways to find and reach hidden fruit, building towers and creating tools to stretch beyond a barrier. Chimpanzees experience insight: they know what it is to have a ‘eureka moment’.

A similar project involving a chimpanzee called Nim Chimpsky failed to teach the animal how to sign language

Desmond Morris, author of the best-selling The Naked Ape, taught a chimp, Congo, to paint. Congo never tried representational art; his style was described as abstract impressionism. But he would carefully balance his paintings, putting, for example, blue on both sides.

He would throw an artistic tantrum if he was told to stop painting before he considered the work finished, and he would refuse to add to a painting he saw as complete. Picasso owned a Congo.

Observations of chimpanzees in the wild, most of them inaugurated by the great anthropologist Jane Goodall, show all kinds of things that humans and chimpanzees have in common.

Chimpanzees make and use tools, they co-operate. They communicate with kisses, embraces, tickling, swaggering and threatening.

She also discovered the most significant thing we have in common: childhood. Chimps and humans spend a long time before taking on the responsibilities (such as breeding) of adult life.

A chimpanzee will spend five years with its mother, suckling and sharing a leafy bed. Orphaned chimps show evidence of clinical depression, and will sometimes be adopted by an older sibling.

Play is essential to humans and chimpanzees: it’s the way we learn skills and behaviour that we in turn pass on. In other words, this is culture. Humans and chimpanzees don’t just pass on things through our genes: we also pass things on by showing and learning and showing again in our turn.

Chimpanzees have emotions and express them. They have a sense of self: unlike your dog, they recognise their reflection in a mirror. It’s clear chimpanzees know mental as well as physical pain. On what grounds, then, would you deny them the right not to be enslaved or imprisoned?

The moral philosopher Peter Singer suggested human history shows an ever-expanding circle of moral concern. At one stage, people from another tribe were outside that circle.

In recent times, women, as well as people of other races and religions, were excluded from the circle, but now they are all accepted inside most societies in the developed world. The next stage is the beginnings of acceptance of non-human animals into the circle.

Singer uses the term ‘speciesism’. It is the same idea as racism and sexism: the denial of rights and moral concern to a group for no reason beyond the personal convenience of others.

This judgment in New York is a small but meaningful strike against speciesism. Perhaps in time it will acquire the significance of the Slavery Abolition Act in 1833 or the Equal Pay Act of 1970.