Christmas is for families, yet the 'traditional' family household is in the minority. What's more, argues Aminatta Forna, it always has been
Terry is spending Christmas with his mother, his step-father and siblings as usual. His annual dread is that the subject of his sexuality will come up and give his ultra-conservative sister and her husband a chance to have a go at his gay lifestyle. He survived last year because his bachelor brother chose Christmas day to introduce a new, adopted teenage son into the family.

Annalise's family life is the envy of her friends whose parents are divorced. They have been together for nearly 40 years. The whole clan gather regularly for birthdays and everyone is always there for Christmas. Annalise would give her right arm not to be, and is currently trying to find an available flight out of the country. No other time of year highlights the changing shape and expectations of families quite like the holiday season.

It seems the debate over the family only grows more intense. Family restorationists now loom from the left as well as the right of the political spectrum, and their campaign gathers pace with the growing recognition that fewer and fewer families conform to tradition: 1.4 million lone parents, 65 per cent of mothers at work, and only a quarter of households now consisting of a married couple with children. On the other side of the debate are the optimists who argue that the family is merely diversifying. But both positions share the same premise - a static notion of what the family was once like.

As politicians tussle over its future, a growing school of thought among sociologists, social historians and psychologists is beginning to dramatically rethink the accepted wisdom of family life, past and present. For example, just this week, the results of a study of estranged families by Professor Robert Bringle were announced at the British Psychological Society's London conference. The study showed that 65 per cent of those questioned were more satisfied with life after becoming estranged from their parents, challenging the mythology that a close-knit family is best for everyone.

Stephanie Coontz is a social historian in the US. Every year she asks her new class to describe what they think of as a "traditional family". Invariably they produce similar images of a golden age of the family, in which gender roles were split, men and women remained married, all framed within a supportive community environment. This is also the politicians' vision of the family which, Coontz argues in her book, The Way We Never Were, didn't actually exist. "It is an amalgam of structures, values and behaviours that never co-existed in the same time and place," she says.

For one short period after the Second World War, lasting no more than about a decade, Britain achieved the closest thing ever to the traditional family. But this was a thoroughly atypical era, characterised by an economy boosted by $3 billion in American aid dollars, consequent full employment for the first (and last) time ever, and a major baby boom. The rise in wages allowed more men than ever to be able to support a wife and family, but even then there were plenty who never rose out of poverty to achieve the dream. If the ideal did exist, says sociologist Annette Lawson, then it did so only for the middle class.

And even among wealthier sectors of society, far from representing an era of innocence, it was the Fifties and the mass production of fridges, vacuum cleaners and other household mod cons which sowed the seeds of today's consumerist culture. Women first started going out to work at that time, says Coontz, not because of feminism but to be able to buy even more goodies for the family household. There's also plenty of evidence to testify to surprisingly high rates of teen pregnancy (usually solved by a shotgun wedding), as well as abandonment by men of their families. But the much lauded low divorce rates of the Fifties were artificially low because the solution to marital problems then was separation rather than divorce.

"There never has been and never was a static family," maintains Lawson. "But if one form lasts 10 years then it is taken as being the dominant form, especially by the middle and upper class, and therefore becomes the way it should be." In the late 20th century, we have become especially adept at "inventing tradition" as a way of dealing with a frightening pace of change.

The truth is that families have always been in a constant state of flux and change. Today's family structure is more like it was 100 years ago - and so, interestingly enough, are many social and economic factors. The job for life, for example, has disappeared, and taken with it the ability to support a family on a single wage. Work is harder to find, and harder to keep, and people work longer hours which correspond far more closely to the kind of hours put in by factory workers before the Second World War. At the same time, reconstituted families were as much a norm of life then as they are now and so were lone families. The reason then, of course, was more likely to be the death of a parent rather than divorce, as Dorit Braun of the Step-Families Association points out, but abandonment was also common. Now the proportions of children being raised either by step-parents or lone parents is almost exactly the same as it was a century ago. And don't forget that was the Victorian era, considered another golden age of the family.

Today, people who argue that the family was never as rosy as it was once depicted, maintain that it therefore isn't currently in crisis either. The eminent sociologist Peter Willmott produced a seminal study of family and kin networks in East London in the Fifties, and is presently working on a follow-up project. "It's a myth that it was better then and a myth that it is worse now," he says. Today, modern telecommunications and transport systems mean that we are as much, perhaps more in touch with our families than ever.

In contemporary myth-making the traditional family is, of course, the happy family. But Bringe's research results have crystallised the earliest signs of a shifting paradigm in thinking within psychology. Margaret Mitchell, a psychologist at Glasgow Caledonian University, argues that the rhetoric of the happy family has distorted the thinking behind much social research and social programmes. She herself has observed that when people go through major traumas, the love and support that is presumed will be provided by their family is often absent. "The myth of the family as a model of unconditional love and support, and the dissonance between people's actual experience and that social model causes a huge amount of anxiety and guilt about not coming from that kind of background," she says. And that's why Christmas, in particular, when all the expectations come to the fore, can be such a trying time.

What Bringe's study shows is that you don't need a happy family to be a normal, balanced human being. He found levels of self-esteem just as high in people who had become estranged from their parents as people who were not. Most of this new work has yet to pervade the political debate and one can only wonder at the effect when it does. Of course, none of this means we should abandon the notion of family (in whatever shape or form) as a worthwhile social structure. But it does mean that we can afford to relax a little and take Christmas in our stride.