'Give your opponent a kiss on the cheek.' Eight life questions to writer Mark Haddon

The huge success of his novel The miraculous incident with the dog in the night - nearly ten million copies sold - brought British writer and visual artist Mark Haddon financial freedom, but not peace of mind. His new novel was recently published, The dolphin. 'I always think: when this is done, then I will have peace. But that carrot on the stick in front of you always ends up hanging a bit further.' Eight life questions to a man who might as well have been a dog.

1. What is the worst thing you have ever done to another person?

'When I was five, I punched a little boy in the playground. It was spectacularly effective as he fell backwards onto his back. Shit, what have I done now, I thought. So that was immediately the last time I did anything nasty to anyone. Between the ages of 12 and 18, I played rugby - still a violent sport in those days. At the start of the match, players would punch each other in the face to find out who was the strongest. Absurd! You know how it is when people fight, it always becomes a mess.'

'My father, a very good rugby player, gave me an important life lesson: the best thing you can do is smile and not react. That scares your opponent much more, because they think they don't care if you get punched in the face. Even better is to give your opponent a kiss on the cheek - not only are you the moral winner, the other person goes over the top. So I got slapped, but didn't hit back. It worked great. I was always covered in blood because I got violent nosebleeds, but I remained unflappable. They thought I was a psychopath, very funny. Not reacting when attacked is by far the best offensive.'

2. Who has shaped you the most?

'To my mind, I mostly did that myself. I had an ordinary childhood, with no major events or traumas. I was on my own a lot. Looking back, I mostly see books and spaces, the house I grew up in, the poster of the universe in my room that I fantasised myself in, rather than in the real world. When I was 11, I was sent to boarding school. At that time, the whole school system was going belly-up and my parents thought it would be better if I went to a public school. I didn't find it a pleasant place. I could hold my own there - I usually get along well with people - but I did not like to belong to a group. I only saw my family about six times a year and besides, you also lose contact with your friends back home.'

'The teaching there was not the best. Most of what I learnt, I taught myself in the library or on my own in my room, learning things that were not in the syllabus but that I enjoyed finding out. Nowadays, as a teacher, you need to have skills in teaching, but back then, discipline was simply enforced. In one of the last years before it was banned, I was slapped by a teacher for something I had not done. That was the most instructive moment of my education.'

'One of the boys asked the teacher afterwards how he could justify to himself that he beat pupils. The teacher replied that he was right and his pupils were not. I thought: people like you I'm not going to trust anymore. Since then I have been sceptical of authority, and as a result I cannot work for a boss - I will not let someone else tell me what I should or should not do. It probably indirectly led to me becoming a writer.'

3. What are you hoping for?

'On contentment. I am very agitated, which is unpleasant. Viewed properly, writing is a curious profession: you spend two years alone in your study, hoping that thousands of strangers will want to read what you write. It's risky, lonely and half the time you ask yourself if it makes sense. But writing for me is the same as eating, breathing or running - it is part of who I am. When I am not writing or making art, I feel like a dog that is not being walked. If, at the end of the day, I haven't added something very small to this world, I feel uncomfortable. Why this is so? Now of course I should give an unequivocal and witty answer, but when something is such an essential part of your existence, the why question is really impossible to answer.'

'Writing is like climbing a mountain. The view from the top is spectacular, that's the reward, but getting there is not easy. I can't do things halfway; if the result is not good enough in my eyes, I get pissed at myself. A lot of it I throw away. With my collection of short stories, at least 30 stories died. That's just the way I work and I'm happy with the result, but it's not efficient or pleasant.'

'Every time I sit down to write, I need more than an average amount of self-confidence to bring it up. The mountain I have to climb is sometimes very steep. At the same time, I have a strong Protestant work ethic, and feel the imperative to work. I always think: when this is done, then I will have peace. But that carrot in front of you always ends up hanging a bit further, doesn't it? Only on days when I have written a thousand good words can I happily put the work away and do something else. If that's not the case, there's always a restlessness gnawing away and I can't quite relax.'

4. What do you marvel at?

'On the infinitely amazing mind of man. At the core, I am curious about what goes on in other people's minds. You can't be a writer otherwise; you put yourself daily in the shoes of people who do strange, inexplicable and sometimes terrible things. This is not always easy, but the trick is to realise again and again that however different people are, they are essentially all alike; we all have the same needs, desires, fears and ambitions. Even an unsympathetic person inside is someone similar to yourself. When you realise that, you can be more understanding and empathetic towards another person.'

'With Christopher, the protagonist in The miraculous incident with the dog in the night, it was pretty easy to get into his skin. He is not so different from people I know well. I wish the term asperger's had not been used on the cover, because in the book Christopher describes himself as a boy with aptitude for maths and with behavioural problems - and the very fact that it is not named anywhere makes a mockery of the labels people are usually given. Labels are only useful in practical matters, but for interpersonal contact they are useless. If you want to understand who someone is, just ask.'

'After university, I worked for a while in an institution where young people lived with physical disabilities, learning or behavioural problems or both. The great thing was that no one was labelled; you didn't know if a child was just shy, had a speech problem or something else. You just said, "Hi, what's your name and how are you doing, tell us a bit about yourself." They were not a label but a human being.'

5. What is the worst thing someone could say about you?

'Hm... Things really only hurt when they contain a kernel of truth, don't you think? If someone says something crude to deliberately hurt you but it doesn't make sense, it loses its power. The same goes for reviews, by the way. If I myself have doubts about a book - which is usually the case - and the reviewer falls over exactly the points I myself had doubts about, it is very unpleasant. The worst review I ever received concerned my book of poetry - really an incredibly false review.'

'The reviewer wrote that it was a good thing he had not read the collection before his heart surgery, because he probably would have stayed in it. And that he himself could write better than me at the age of nine. It was so negative that it became funny because, to my mind, it had hardly any relation to the book. And sometimes someone comes to my house for an interview, and they then put a pointed remark or description in the article that is meant to be funny, but which puts me down distorted and rather crude in front of twenty thousand readers. In my private life, fortunately, such situations do not occur, because I choose carefully who I deal with.'

6. Which animal would you like to be?

'I already am one: a dog. I prefer to run or walk every day, I love bad weather, mud and rain. I spin endlessly before falling asleep, like a dog spins in circles. And I have a very highly developed sense of smell. I sometimes say to someone, "You smell interesting" or "Where have you been?" I know what my friends smell like, what face care products they use. If my wife applies cream in the bathroom, I can smell it here in my study, two floors below. I smell everything. In terms of character, I am also a dog. Sometimes I want to run around, but I also often retreat to my basket, a big round chair like a cocoon. When I sit in there, my children suddenly sound a whole lot quieter.'

7. What was your best decision?

'Deciding to go to a party at 77 Hornsey Park Road in north London in 1991. There I met Sos, my wife, who had come along with a friend I had known for years. We got talking by the cooker in the kitchen and didn't stop talking; we leaned against the gas knobs and at one point smelt a strong smell of gas - we're lucky the place didn't explode. Sos is my best friend, and always will be. My agent once described me as the uxorious Mark Haddon. Do you know that word? It means: fond of your spouse. Sos and I share a lot of interests, like sports, literature, art, politics. But we can also sit together and just be alone. Being with Sos is like being alone, but better.'

8. What was the happiest moment of your life?

'Something that is guaranteed to make me feel happy is a long run and then another hour or an hour and a half of walking in a beautiful rural place, like Wytham Woods, the most beautiful part of Oxford. Running along the river and walking through the woods makes me feel deeply happy. Sure, the endorphins help too. A few times a week I need that peace and quiet, the absence of human influences. The chatter in my head goes on continuously and if I've been running for an hour and then walking, it's finally quiet between my ears for a while.'