Philip Hensher: Fiction takes you to places that life can't

It takes a novelist, not a psychologist, to explain why people sometimes behave out of character

What's it like to die? There's no answer to this cheerful question, or there shouldn't be.

People have told us what it's like nearly to die, to come back from the brink. The external process of death has been gone over in great detail. But no one has definitively returned from the other side, to tell us what it's like to feel the last breath leaving your body. We don't know anything about it.

Or rather, we shouldn't know anything about it. In 1886, Tolstoy published a short story called "The Death of Ivan Ilych", which follows a fairly unremarkable man to the complete extinction of life. After reading that, you feel you know what death will be like: "Suddenly some force struck him in the chest and side, making it still harder to breathe, and he fell through the hole and there at the bottom was a light. What had happened to him was like the sensation one sometimes experiences in a railway carriage when one thinks one is going backwards while one is really going forwards and suddenly becomes aware of the real direction." How could Tolstoy possibly know that? You will read any number of academic studies of the processes of death without coming near the novelist's instinctive understanding.

A wonderful Canadian academic and psychologist, Keith Oatley, has carried out some research on readers and non-readers of fiction, and has questioned this widespread assumption. Speaking to the Today programme this week, he shared his conclusion that habitual readers of novels were much better at coping with social situations and with a wide range of human beings. The usual image of the thick-lensed bookworm who can't cope with people – Philip Larkin's character who says "when getting my nose in a book/cured most things short of school" – is far from reality.

Well, all of us Dewey-botherers knew that. I guess from day one, I had a general sense that novels were going to introduce me to more sorts of people than life would. There was Mummy and Daddy and my big sister; there was Mr and Mrs Griffiths next door, and there were the Skittles at the end of the garden. On the other hand, if you opened a book, there wasDorothy and her friends the lion and the tinman and a boy called Tip, later transformed into Princess Glinda of Oz.

Later on, there were girls who went away to a super school called Malory Towers, not very much like anyone I knew; there were robots and Boy Detectives and a talking spider called Charlotte (who died) and a foul-tempered talking pudding and a larrikin koala, some rather intimidating children called Bastable and a boy called Philip Pirrip.

Whenever I hear someone say "I don't read novels – I prefer to read about the truth," I wonder about their notion of "the truth". The conviction that reading fiction is a dispensable part of a rich, full life is a widely held one. Members of my own family, to this day, will say to me if they find me engrossed in a thriller, "If you're not doing anything...".

The saddest expression of this attitude must be Quentin Crisp's famous landlady, who was always commenting on his actions. If she came across him having his lunch, she would say "Eating." If she saw him sewing a button on, she would say "Mending. Once, she found him reading a novel. She looked at him, and said "Waiting."

I don't suppose any reader complains for a moment that his life is failing to introduce him to as interesting a collection of people as he will find in 10 minutes in the nearest bookshop. On the other hand, real life has a way of intruding itself. You can't live your life entirely within the pages of a novel, as much as some of us attempt to. And when real life starts to expand beyond the small domestic circle, then your reading of novels is going to prepare you for what life can hold. India is not completely strange if you have read Narayan; nor is old age after Elizabeth Taylor's Mrs Palfrey at the Claremont.

Fiction won't tell you the whole story, but it will take you to places that life won't – Sicilian ducal houses, 13th-century convents, cities in Calvino that never existed. And sometimes with a shock of recognition, you meet in real life a friend from a book. I have a dear old German friend who, the very first time I met him, I thought "Snufkin". He really was Tove Jansson's charismatic, silent, solitary wanderer to the life. I wouldn't have known what to make of him without those magical novels.

How do novelists do it? They throw themselves into lives very unlike their own; their imaginative reconstructions are as apt to be as convincing as reports back from experience. Tolstoy knows what it is like to die; Stephen Crane tells us what war is like in The Red Badge of Courage, only experiencing battle after writing it. Conrad undoubtedly knew what it was like to endure a stupendous tropical storm. Thousands of sailors went through events like the ones described in Typhoon, but only one had the imaginative sympathy to write it down.

As Martin Amis has said, we still have no real idea what it is like to go into space. No one who has done so has had the ability to write well about the experience. Whatever systematic analysis is undertaken of a human experience, still the novelist's human spread seems the most substantial, authentic, accurate account.

Psychologists can offer explanations of behaviour, but they can't explain why people sometimes act out of character, or against their own interests. Even so subtle an analyst of behaviour as Erving Goffman, say, would struggle to account for the moment at the end of Vanity Fair where Becky Sharp hands Amelia Osborne the letter, destroying her own interests. And yet we know it to be true in the deepest sense.

The writer Marc Abrahams has shared an amusing encounter with a psychologist, who told him: "Whenever any group of really good research psychologists gets together socially, after a few drinks they always – and I do mean always – talk about why novelists are so much better at it than we are."

It's true. No psychologist is as good a psychologist as Graham Greene, let alone Tolstoy. And it's also true that no social life contains the range and interest of a shelf of novels. We love our friends: human beings fascinate us endlessly; and to teach us how they work, there are always novels. I've never met anyone remotely like Emma Bovary, Miss Flite, or Belinda, the madcap genius of the Fourth Form at Malory Towers. But one day, they'll come along, and when they do, I'll recognise them instantly.