When Joyce Hatto died of cancer at the age of 77 in 2006, The Guardian hailed her as “one of the greatest pianists Britain has ever produced.” It had been an extraordinary career. Up until her 50s she had only been a footling figure on the music scene, recording an undistinguished but workable selection of minor classics. In the 1970s she had retired to the countryside to battle cancer – at least, so her story went.

Then from 1989 onwards, an extraordinary series of recordings emerged from her Cambridgeshire cottage. Liszt, Bach, Mozart... all played with astonishing depth and virtuosity. This aging, sick pianist managed passages with an agility even the greatest masters of the 20th century would find hard to match. The meaning of these works was added poignancy by the fact that the player was an elderly woman who had battled cancer for thirty years.

It was only after she died a lone critic spotted the uncanny similarity between one of her recordings and one by the pianist Lazlo Simon. Soon the entire Hatto oeuvre was being taken apart, bar by bar. It was a jigsaw puzzle of forgeries created by her husband, recording engineer William Barrington-Coupe, who'd used technology to disguise, even enhance, existing masterpieces and pass them of as his wife's.

For art philosopher Denis Dutton the whole notion of forgery – and why we are so upset when a work we loved is unveiled as a fake — turns the critical orthodoxy of the last fifty years on its head. Intentionalism — the idea that what an author intended by his work is crucial to our undersanding of it — has been a dirty word. Foucault and Barthes underscored the point. A work is simply a text, a collection of semiotic signals, whose meaning is dependent on the context in which it is delivered. What the artist says they meant by it is not relevant.

Dutton believes this is utterly wrong. Hatto's work appeared meaningful when it was thought to be created by an elderly, frail prodigy. The same notes meant nothing when the fraud emerged. More importantly, Dutton believes all art is always intentionalist because it is a fundamental act of human communication between artist and audience – as fundamental almost as food and water. Indeed, the urge to create art and the ability to comprehend it is one of the Darwinian mechanisms that make homo sapiens such a remarkable species.  

Denis Dutton's book The Art Instinct is about exactly what it says on the box; it is about what he believes is the instinct to create art. Dutton's Darwinian view suggests that art is not some luxury add-on of human culture, it is hard-wired in us. Language gave early homo sapiens the ability to describe that there was food over the other side of a hill. Art gave us the power to imagine it, and to harness the imagination of our fellows with rich descriptions of the imagined food. Art, he says, not only provides a complex mechanism by which we can predict the world, it is a means to empathetically share the worldview of another person — which is why we're so disappointed in Ms Hatto. The surprising persistence of narrative as a form throughout human history - despite the all the attempts of modernism to quash it — suggests to Dutton that this is a fundamental form that allows us to understand kinship, mortality and progress. Art was a central component in our evolutionary adaptation; it is a fundamental part of our life now.   

This is a brilliant and insightful idea. If only he had stopped there.

But as you will have twigged by now The Art Instinct also carries its on ideological freight with it. It is a cunning assault on post-modernism and its pal cultural relativism, though a novel one in that it bases its case on evolutionary psychology. Dutton reminds us that our instincts were formed during the 80,000 human generations that endured during the Pleistocene era; it has been only 500 generations since we started living in cities, practicing agriculture and writing. Our instincts are Pleistocene. Why do we universally appear love landscape paintings that includes hills, streams and a hint of woodland? Because they represent the kind of landscape our Pleistocene ancestors dreamed of.

On one level this is a thrilling articulation of the need for art. Created during the time when the human species struggled for survival, it now persists as a crucial part of the  human process.

He goes further. Art is not just explained as an adaptive mechanism of survival, but also a crucial factor in sexual selection. Just as Darwin understood that the the peacock's apparently superfluous feathers display genetic fitness, the human's ability to demonstrate artistic flair is an example of sexual display.

(If that sounds absurd, talk to teenage boys forming their first bands. At 18, the primary impulse of most boys forming a band is less than aesthetic.)

Art is like language. The mechanisms by which we create it and understand it are hard wired. In this he takes on Darwinists like Steven Pinker, who argues that art is fundamentally only a by-product of adaptation, rather than an adaptation. If, as Pinker says, art is “cheescake for the mind”, it is a necessary cheesecake.

So far so good — but like so much of evolutionary psychology's attempt to explain human behaviour, while Dutton's thesis illuminates a genetic origin for behaviour, it ultimately reduces all culture to function. And that's a problem. Of course Dutton's functionalism is incredibly sophisticated; art,he says, plays a dazzling and kaliedoscopic array of roles in human survival and sexual selection. But it is still functionalism, and seeking to explain all culture through the lens of adaptation misses the unique fact of human culture; that any individual's notion of culture does not stem only from biology, but from culture itself. In art and culture, biology creates a system it does not control. That's the adaptive ace card for humanity – or joker, depending on which way you look at it. This unique adaptiveness is reflected in the latest thinking in neuroscience, which sees increasingly sees the mind as plastic, not simply wired from the Pleistocene era, but changing with the environment that surrounds it.

I chose rock music earlier as an example; it's one that shows one obivious strength of Dutton's approach. It also shows his shortcomings. Though invented by young men out of an impulse that may well have procreatively instinctive roots, rock music is now an autonomous industrial artform, and one in which lusty young men no longer have the field to themselves. Culture may be informed by instinct, but it is much more than instinct.

If you want to see more precisely where the cracks lie, take the incest taboo. Dutton uses the example of the incest taboo several times as a fundamental example of the cultural articulation of a genetically useful strategy. But the real lesson of the incest taboo, as anthropologists like Levi-Strauss pointed out long ago, is that though the fact of an incest taboo is universal in human culture, every culture implements it differently. In one a man's brother's sister-in law might be strictly out of bounds, in another she's not.

In attacking relativism he similarly overstretches himself. A social anthropologist might say that an outsider might be blind to the cultural meaning of a pot, created as a sacred relic, compared to an almost similar-looking pot created with purely utility in mind. Only someone from that same tribe, or an anthropologist, can tell the difference. Dutton lambasts the social anthropologist's arrogance. Our art instinct allows us to understand the difference between meaningful items and the pedestrian ones.

This is elevating our art instinct to the level of pure mysticism. The British Museum is full of artefacts that were misclassified during the 19th centuries first flush of ethnographic enthusiasm. You don't have to defend moral relativism to know that, as artists are well aware, context is all important to understanding.  The growth of aggressive secular humanism of the Richard Dawkins variety alongside the spread of a new strand of hardcore Islam in our society shows how far even a single society can contain cultural and aesthetic worldviews that are both exclusive, divergent and, at times, mutually incomprehensible. Understanding other cultures is by no means impossible – but on occasion it requires hard work and empathy. It is not automatic. Mere instinct is not enough.

Buy Denis Dutton's Art Instinct from the RSA Bookshop