Australia has embarked on an experiment in dividing the care of children between separated parents. Adele Horin reports.

No one said raising children after divorce would be easy. But for Barbara Strand* it became harder once the Family Court ordered her a year ago to share the care of her three children with her former husband. He was verbally abusive, drank, gambled and had trouble holding down a job. He told his partner he wanted shared care - the 50-50 arrangement - so he would never have to pay her child support.

"I wouldn't mind if he had a hippy, relaxed style of parenting," she said, admitting her own style is strong on routine. "But his approach is 'I don't-give-a damn' … The school calls me to bail the kids out because he hasn't given them lunch, and he doesn't believe homework is essential so I'm constantly having to play catch-up."

Symbolic of his lackadaisical approach, in her eye, is his refusal to let the children play afternoon sport. He won't take the girls to ballet lessons, either. The girls don't want to spend alternating weeks with their father although the son is happy enough to comply. Now communication between the parents is nearly non-existent; even email, the divorced parent's best friend, is proving too provocative.

"I tell the children what the court told me - it's the law and I must abide by it," she said. "The court psychologist told me his verbal violence towards me has nothing to do with his parenting skills. But sharing my children with a man who is mentally, emotionally and verbally abusive is not a good thing."

Australia is embarking on a grand experiment with its children. Increasing numbers of them are spending equal time with each of their separated parents, hauling suitcases, sport uniforms, tennis racquets, laptops and sometimes their "communication" books with parents' instructions to each other, from one home to the other.

It is not a new arrangement. But the 2006 amendments to the Family Law Act - the most significant in 30 years - provided the impetus to transform the culture of post-separation parenting. The numbers of divorced parents with equal - or near-equal - time is steadily rising. Of all new cases registered with the Child Support Agency in the year to June, 17 per cent were shared or near-equal time arrangements. In the year to June 2003, by comparison, of all new cases registered only 9 per cent were in that category.

More "father time" was what many children and fathers craved. It was what many worn-out solo mothers - contrary to stereotype - also wanted, research by the Australian Institute of Family Studies has shown. The cultural shift towards shared care should be cause for celebration. But some experts still hold serious reservations. In the past, parents who pioneered shared care had co-operative and egalitarian values. Many were well-educated, dual-career couples. But it is unknown how many highly conflicted parents are now trying shared care, and what price their children are paying.

"I'm worried a group of conflicted families is being drawn into shared care for all the wrong reasons," says Zoe Rathus, a family law expert from Griffith University. "And I'm worried kids feel they are carrying the burden of making divorce fair for their parents."

Last week preliminary results from the first major study of shared care, involving 5000 separated and divorced parents with various child residence arrangements, were released. They showed overall that children in shared care are no worse off - and no better off - than those who see the non-resident parent every second weekend. If the results did not fulfil the hopes of the boosters of shared care, nor did they confirm the fears of the shared care detractors. The survey - by Bruce Smyth and Bryan Rodgers, of the Australian National University - also showed children whose parents are locked in conflict have more problems than those with co-operative parents, regardless of the arrangement.

It was concern about "father absence" that propelled the Howard government to put more focus on shared parenting in family law and in the child support system. About one in four children under 18 from separated families virtually never sees their non-resident parent, according to the Bureau of Statistics.

"Far too many young boys are growing up without proper male role models," the former prime minister John Howard said in 2003. "They are not infrequently in the overwhelming care and custody of their mothers."

Now that the reforms he set in train have been in place for more than two years, some experts are worried the response to "father absence" may have gone too far. Associate Professor Bruce Smyth says the reforms have encouraged an over-focus on numbers - 50-50, 70-30, 80-20 - turning parents into petty time accountants. "Separated parents can lose sight of what is most important to their children: spending time in a broad spectrum of activities and experiences with their parents," he said.

Overseas research by Carol Smart, the British sociologist who interviewed children, has shown the unsuccessful cases of shared parenting involved children who felt they were "living lives that were basically parent-oriented". They felt the arrangement was agreed upon to satisfy their parents' needs or, if parents could not agree, to strike a compromise for the adults.

In Australia, Jennifer McIntosh, a psychologist, admits she sees the "bad news" kids. "I see the train wrecks." Her research into shared care among a small sample of high-conflict families has made her particularly concerned about pre-school-aged children shuttling between parents fighting hot or cold wars. And she has more general concerns about making shared care prescriptive in legislation when its success appears to depend on so many individual factors.

"Children benefit demonstrably from time with parents who are warm and available," she said. "But they are seriously strained by too much time with a mother or father who is not. I see kids subject to such a lot of strain and tension. They expend so much energy 'reading the climate', learning what is OK to say, having to be vigilant. And over the years I think it takes a toll." Her hope is that family mediators, lawyers and judges will put more effort into distinguishing families ready or approaching readiness for shared care from those who will never be.

When Deborah Arnold first sent her children to their father for the agreed three days a week, they had to be dragged screaming. It broke her heart. Eight years later, with the girls aged 13 and 10, they go with resignation. "He is a bullying, controlling, dominant man and I just gave in," said Deborah. "I think they are as intimidated as I am. I have tried several times to change the arrangement because the girls want extra time with me. But he won't agree. If I go to court I'm scared I'll end up in a worse scenario with him getting more time. I have to endure and they have to as well." The older daughter, barely a teenager, has been diagnosed with depression.

The new Family Law Act is often misunderstood. Equal time is not the prescribed starting point for negotiations over children's arrangements; rather the changes introduced a presumption of "shared parental responsibility" for major long-term decisions in a child's life. But then the judge or lawyer or adviser must favourably consider whether spending "equal, or substantial and significant time" with each parent will be practicable and in the best interests of the child. The law also emphasises protection of children from family violence.

In the community, and in lawyers' chambers, the distinction between shared "responsibility" and shared "time" has blurred. All the talk about shared care dramatically raised some parents' expectations, say family law lawyers.

Within the Family Court there is surprising evidence from McIntosh's studies, based on small samples, that highly conflicted parents who go to court are more likely to end up with shared care than do parents who settle children's matters themselves.

One Family Court judge in Brisbane, Tim Carmody, resigned from the bench after five years, citing the "failure" of the new system as a factor. Judges were required to apply a presumption of shared responsibility to the most hostile of couples - the 5 per cent who end up before a judge - and then consider giving them equal time with their children, he said. "It created a real crisis for me; I just couldn't keep doing it."

A much-anticipated Family Court study of the outcomes of litigated parenting matters since July 2006 is yet to be released.

Despite its trail of forgotten school shoes and misplaced homework, shared care is proving successful for many parents. Indeed parents, in particular, seem to be the beneficiaries, according to the study of 5000 parents. They are happier in themselves and with the arrangement than those in other arrangements.

Karen and Robert Finch are typical. They separated seven years ago, and it "felt like a slap in the face" to Karen when he wanted the children 60 per cent of the time. They ended up in court and eventually settled on a 50-50 arrangement. The court experience was a "wake-up call … horrible and stupid", Karen says. It made them both realise "at the core, it's about the children". She acknowledges that Robert is "a good dad" who has a strong relationship with his sons. "I have never thought the typical arrangement of every second weekend with dad was in their best interests."

So the boys spend half the week with her, half with him and each parent is responsible for the same extracurricular activities every week. Email and text messages are the parents' main mode of communication with an occasional family breakfast for big discussions. The secret to successful co-parenting is to control anger, and to let go on issues that aren't important, she says. "We put a lot of effort into having a united front and being consistent in the way we parent."

Between overt hostility and co-operation are people like Paul, locked in a cold war with his former partner. "As the children became older, there's been more disagreement over parenting issues," he says. He disapproves of his former wife's lax parenting style. So the couple engage in parallel parenting. They never talk or see each other, and he finds it "easier to duplicate than negotiate" over items such as the forgotten school shoes. "I don't have to like the person to make the arrangement work," he says. "But it's not ideal."

As more fathers become involved in child rearing, shared care will continue to rise when relationships break up. Even when parents, such as Marilyn and Guido, have amicably negotiated the shoals of shared parenting for 10 years, doubts linger about the effect on the children. Of sons 16 and 19, Marilyn says: "It's hard on them. They hated moving and packing all the time; different routines, different meal times. As they get older, there is a sense of duty. Two weeks ago my 16-year-old decided to live with me. He'd had enough. But it was good, too. They had two homes, they were loved by both parents, their father didn't have to be a weekend sugar daddy. We did our best."