Trying to get to the bottom of it in her new book, Watching the English, is social anthropologist Kate Fox, a girlish 42-year-old who speaks enthusiastically about her three years researching and writing this study of English manners. Only recently married, the Cambridge-educated blonde gives the impression of being more than a touch eccentric and herself a late bloomer socially.

'Jumping ahead of people in queues to gauge their reaction was one of the hardest things I've ever had to do,' she says. 'A lot of the research turned out to be tests of my own Englishness. For the English, queue-jumping is a deadly sin, which it isn't in other cultures,' she says. 'At the same time, that makes it easier because we're so reticent and unassertive. If you're English a raised eyebrow is a sort of stab to the heart.

'Most stereotypes are based on at least a grain of truth. They don't just come out of thin air. There are reasons people talk about English reserve.

'What I found surprising was that these are more complicated than they seem. It's not as simple as just saying we're reserved, or we apologise a lot. Our reserve is a symptom of what I call social dis-ease - our chronic social inhibitions. But social dis-ease is more than that because reserve is just one side. The other side is the other thing we English are famous for: hooliganism and loutishness. These are part of the same disorder.'

Fox cut her literary teeth a few years ago with The Racing Tribe, about the manners and etiquette of punters at the racetrack. In this far more ambitious follow-up, she breaks behaviour down into rules and codes, giving them labels such as 'the ambivalence rule' or 'sex talk rules', or the exciting sounding but unenlightening 'post-coital Englishness'.

'If I was commentating on another culture I'd probably be too polite to call it a social condition. I'd be too English. In a way, that's the good thing about studying and analysing your own native culture - you can actually be much more rude, and in a sense more accurate.'

Fox says the English value their privacy, or at least their ability to keep a distance between themselves and others. In this way, they can be who they want to be, from eccentrics to terminally boring. Fox calls it pulling up the drawbridge.

She partly identifies a sense of fairness behind English behaviour, but says this has its own complex permutations that can swing to extremes of hypocrisy. 'Breaches of fair play incite more righteous indignation than any other.

'The English reserve has been put down to all sorts of things, including arrogance, which I think to some extent is true.

'We do have difficulty engaging socially in a friendly way with other human beings, including other English people. We're becoming much more insecure about our position in the world and we're heavily into self-flagellation.

'The trouble is that the English generally aren't very good at saying what we mean or meaning what we say. English males in particular seem to have a bit of a handicap with flirting.'

Fox is herself a strange amalgam, having been brought up in Britain, America and France. Her father, Robin, is an anthropologist at Rutgers University. She divides her time between Oxford, where she co-directs the Social Issues Research Centre, and the Wimbledon home of her new husband, Henry Marsh, a London brain surgeon.

Fox says her father taught her to be objective, although she adds 'it's difficult to be objective about one's own culture.'

But she seems suited to it. 'I have probably a bad tendency to detach a bit too much. Friends get annoyed with me if they take me to a concert and I spend the entire time watching the audience.'

Fox is a living example of the complexities of the behaviour she describes. Although she's 'terribly English' in her manners (which she says is a self-conscious reaction to her ever-changing homes as a child) and, to a degree, needy of love or recognition, she's awkward.

Tending to turn conversation or analysis into stories about herself, she seems perpetually fearful of being forgotten or feeling invisible, and her book is full of references to herself and her father. Her insularity is a complicated manifestation of aspects of the English as a whole.

'When we go abroad we tend to set up these totally self-contained insular little English enclaves and maintain a little oasis of English culture. Either that or we try to impose our ethos on the local population.

'Relating to other cultures is not one of our strong points. It's not one of the things we tend to be very proud of. We're a strange mixture. In some ways, we're very tolerant. We're less xenophobic than most other cultures. Normally, we're good at moderation.

'We do most things in moderation - except moderation, which we take to ludicrous extremes. There's the small- island factor, too. We're insular and somewhat protective. We're territorial. Home is what the English have instead of social skills.'