Whether headed by singles, same-sex couples, step-parents or the nuclear duo model, the 21st century family’s sheer diversity may prove to be its strength.

Wake up to the new century and smell the roses. Toss aside your millennium angst – it belongs to the dying months of 1999. Society, family, relationships, marriage, sex, love – all will live on in the 21st century, but we will have to adjust to an even more dramatic pace of change in the years ahead.

Conservatives who espouse “family values” have long lamented that the family unit (“the backbone of society”) is in crisis, that our sexual mores have gone to permissive hell and that we have become slaves to self-indulgence. And if you subscribe to the view that television imitates life, you could be forgiven for agreeing with them. In the Leave it to Beaver and Father Knows Best world of the 1950s, the family and childcare were wrapped in a serene, reassuring idealism. By the 1990s this had metamorphosed into guilt-free sex (Melrose Pace, Sex and the City), withering satires on the family (Married With Children, The Simpsons), and new-wave cohabitation (Will and Grace, Dharma and Greg).

But the Zeitgeist is all in how you look at it. In the buttoned-down 1950s, when automatic marriage and motherhood were the norm, wife-beating, incest and other sexual abuses of children were just as common as today, but the difference was they were hidden behind a wall of silence.

Women were chained to the sink and the pram; now thanks to decades of feminist striving, they have become everything from astronauts to firefighters to CEOs. Mothers may be spending less time at home, but they are also giving increased attention to each child, studies show, thanks to the increasing number of smaller families. In the 1950s, fathers rarely took an interest in their children until they were old enough to kick a football; today, they are present at their child’s birth and share an active role in childcare.

Viewed in this context, we have undergone a sea change in attitudes, nearly all of them positive, which makes the brave new frontier of family and relationships not quite so scary. The prototype 21st century family will be hard to pin down – not because it will be weaker, but because it will be so incredibly vital and diverse.

We will soon call off our century-long search for the key to rearing a perfect child – not because one doesn’t exist. Children become dysfunctional – self-centred and alienated – as a consequence of indifference, domestic violence, sexual abuse and poverty, not because they were brought up by a single mother, a gay father, a step-parent or in a “blended” family. The common-sense elements of child-rearing remain the essentials here – love and affection, liberal doses of security and comfort, as well as a high exposure to positive learning experiences.

Forty years of surveys have told us that divorce is bad for children, but so are long, loveless marriages riven by parental conflict. Evidence increasingly suggests that frosty or tense marriages take longer to “wash out” in children than sudden, painful divorces. “Staying in a bad marriage is counter-productive,” says Michael Bittman, senior research fellow at the University of NSW. “If you are miserable, how will that help your children?”

This hasn’t stopped six American states over the past three years – in a knee-jerk reaction to rising divorce rates – from toughening laws to make divorce more difficult. “Any attempt over the next decade or two to tighten up the divorce laws in Australia would be deeply unpopular,” says Peter McDonald, professor of demography at the Australian National University. “Tougher divorce laws don’t stop marriages from breaking down; instead, people just separate.”

Nor is there one shred of evidence to support the notion that sexually “unorthodox” parents – lesbian mothers or gay fathers – create confused or problem children. In fact, the offspring of lesbian mothers, studies show, tend to be more tolerant and less rebellious than their peers – and, almost invariably, heterosexual. “Some years ago a study examined the children of parents who had undergone sexual reassignment,” says Bob Montgomery, a professor of psychology at Queensland’s Bond University. “The children of these transsexuals were found to be disgustingly normal. They kept saying, ‘I know Dad is a little odd, but I don’t intend to be like him.’ Kids tend to leave home instilled with pretty orthodox values and images derived from the larger culture.”

In the early 21st century, Montgomery hopes minority groups will no longer be political punching bags for right-wing proponents of the family. The family has been reshaped by seismic economic shifts, not because of gay rights or single mums.

To take the pulse of the Australian family in the early 21st century, stroll through any busy shopping centre and notice how the human traffic is still dominated by mum, dad and the kids. The nuclear family may now represent a minority of households (49 per cent), but this doesn’t mean the family unit is destined for the scrapheap.

Unpack the statistics carefully and you’ll find there has been a boom in “empty nest households” – those where the children have left home (in short former nuclear families). Add to this a growth in one-person households and a dramatic increase in couples having children later in life – all natural outcomes of our ageing population. “Reports of the demise of the nuclear family have been greatly exaggerated,” says Bittman. “Conservatives may wring their hands and cry that the family is in a downward spiral, but the truth is most children are born and raised in two-parent families.” He’s right: the over-whelming majority of Australia’s 4.7 million families – 82 per cent, according to the Australian Bureau of Statistics – are two-parent households.

Certainly, the fertility rate has been dropping. First it was busy career women who dodged the mummy track; now it’s many working-class women. But the trend to smaller families or no children has been occurring for more than a century (in 1921 32 per cent of the population was under 15; today, the figure hovers around 20 per cent). And that other so-called modern phenomenon – the blended, Brady Bunch – type step-family – is not entirely new, either. Before the 20th century, it was not uncommon for a man to marry two or three times because so many women died during childbirth.

Forget conventional wisdom and view the trends of the baby boom as a historical exception rather than a rule, and the family doesn’t look quite so fragile. At the height of the baby boom in the mid – 1950s, the rate of childlessness was less than half that of previous generations. In the late 19th century, around 17 per cent of women never married; this fell to an unprecedented low of six per cent during the ’50s and is likely to climb to around 30 per cent within a decade or so.

Australians love to slap and tickle. According to an international survey conducted by condom-maker Durex, we are the world’s most frequent lovers after the French (we have sex on average 116 times a year, compared with the international average of 109).

What the new medical technologies – in-vitro fertilisation, egg and sperm donation, surrogacy and sex selection – will do is solve a growing problem in post-industrial countries: declining sperm counts and growing female infertility. Women will also be able to bear children into late middle age – as in the case of Arceli Keh, the Californian woman who gave birth in 1996 through IVF at the age of 63.

But the human sexual impulse, of course, is not just about reproduction, despite what pro-family moralists would have us believe. In the near future, ageing baby boomers (there will be three million grandparents in Australia by 2030) will be able to spark up their love lives with a new generation of libido-enhancers (an astounding 40 per cent of women and 30 per cent of men have sexual problems). We have already seen great advances in the treatment of impotence, which is now seen by doctors to have a physiological rather than psychological basis, in most cases. “A man’s sense of himself is absurdly dependent on his ability to get and maintain an erection,” says Robert Nye, author of Masculinity and Male Codes of Honour in Modern France. “Drugs will soon be found that will increase libido without any side-effects. When this occurs, the Viagra revolution will pale into insignificance.”

But what of the counter-revolution? After all a clitoris has twice as many nerve fibres as a penis and has the capacity to be a sexual powerhouse into old age. “Women are having sex at an earlier age, are having more partners and are more inclined to make the first move,” Says Dr Marilyn Lake, author of Getting Equal: The History of Feminism in Australia. “Like men, they now want to shop around before settling down. For centuries, culture has dictated sexual probity for women, but this is rapidly vanishing in developed countries.”

Recent research indicates there may even be an evolutionary advantage to female promiscuity. And if women were meant to be the innately monogamous sex, why the attempts to quell their sexual appetites in parts of Africa and the Middle East through barbaric practices such as female circumcision?