Two studies of human development, one launched in the 1970s and the other from earlier this year, reveal how different New Zealand society is today.

Rachel Chamberlain reckons her childhood in Dunedin in the 1970s "couldn't have been better".

Now 38 and living in Napier with her husband and three children, Chamberlain is one of 1037 babies born in Dunedin during 1972 and 1973 who have been followed by researchers ever since in New Zealand's oldest longitudinal study of human development.

Every two years at first, then every three years and now about every five years, she has returned to Otago University to have a comprehensive health check-up and answer questions on everything from education to illegal behaviour, from her income to her sex life.

This rich data over such a long period has allowed researchers to trace the long-term effects of genes and experiences dating back to early in life - most famously a gene that, when combined with maltreatment in childhood, is associated with convictions for violence in adulthood.

Almost four decades later a new longitudinal study, Growing Up in New Zealand, was launched this week by Auckland University. The first results, from interviews with expectant parents three months before their babies were born, reveal enormous changes in our society since 1972.

Dunedin in 1972
Chamberlain, like 97 per cent of the Dunedin sample, comes from a "standard New Zealand European" family. Her mother, like 77 per cent of the Dunedin mothers, was still at home with the children when Chamberlain turned 3.

"Mum was at home for the greater part of my childhood. She was very involved with everything we did," she says. "Cheesy as it sounds, it was great to come home to afternoon teas and things and your mum waiting for you."

Society was stable. Ninety-five per cent of the Dunedin parents were legally married. The Chamberlains stayed in their house on the hill until they moved to Auckland when Rachel was 15.

Home ownership in New Zealand, fuelled by rights to capitalise the universal family benefit and borrow at 3 per cent from State Advances, was on a rising trend - up from 50 per cent in 1936 to 68 per cent in 1971 and heading to a 73 per cent peak in 1986.

In 1970 only 983 New Zealanders were on the unemployment benefit and only 2 per cent of working-aged people were on benefits of any kind. The domestic purposes benefit (DPB) had not yet been invented.

On the other hand, women definitely knew that their place was in the home. And babies were weaned abruptly from their breasts - 45 per cent of the Dunedin mothers did not breastfeed at all, and more than half of those who did stopped within three months.

A new economy
The transformation of our society since 1972 arguably started when Britain joined the European Community on January 1, 1973, shattering the protected market that had been the basis of New Zealand's prosperity and stability.

This domestic crisis was soon followed by global inflation dramatised by two "oil shocks". New governments in Britain, the US and later New Zealand responded with savage cuts in public spending. The family benefit was axed and State Advances mortgages were sold.

Industry subsidies and protections were scrapped, unemployment soared and welfare numbers peaked at almost 16 per cent of all working-aged people in the early 1990s. Even those in work saw a widening gap between rich and poor as national wage awards were replaced by a market where employers held most of the power.

Top tax rates were halved and GST was imposed across the board, shifting much of the tax burden on to poorer families. Real equivalised incomes for the richest tenth of the population leapt by 44 per cent between 1985 and 2009, while those of the poorest tenth crept up by only 14 per cent.

Many of those old enough or rich enough to have bought their own houses now rent out their investment properties to younger and poorer families. Home ownership dropped back to 63 per cent by 2006. For families with dependent children it was 62 per cent, and in the new Growing Up in NZ study it is just 52 per cent.

The Growing Up study of 6822 babies born in the Auckland, Counties-Manukau and Waikato health districts between February 2009 and June this year has found that 40 per cent of them live in the most deprived 30 per cent of areas, as measured by a range of indicators including income, unemployment and not owning a home, a car or a phone.

Professor Peter Crampton, an Otago University researcher who helped develop the deprivation index, says poverty is now concentrated in families with children. Nationally 42 per cent of families with children (and 55 per cent of Maori and 70 per cent of Pacific people) live in the most deprived 30 per cent of areas.

"The welfare state, over decades, progressively maintained families with children in poverty, and the elderly - through its super scheme - out of poverty, and the reason for that is the straightforward political one - elderly people vote, children don't," he says. "The concentration of poverty in New Zealand in families with children is a direct consequence of our welfare policies and we could change it any time if we wanted to."

Of course, except for Maori and Pacific people, poverty still affects only a minority. In the Growing Up sample only 5 per cent of the households get the DPB, 5 per cent are on sickness or invalid benefits and 5 per cent are on the dole. Four-fifths (81 per cent) of the fathers and 55 per cent of the mothers were in paid work three months before the birth.

Total household income was under $50,000 for only 24 per cent of the families, up to $70,000 for another 17 per cent, between $70,000 and $100,000 for 23 per cent and above $100,000 for 37 per cent.

The deprivation figures suggest the Growing Up sample is only slightly biased towards higher earners. Unlike the Dunedin group, who were contacted from hospital records for every baby born in Dunedin, the Growing Up mothers were recruited through midwives and in shopping malls so they could be interviewed first in pregnancy. The sample represents about a third of the 20,000 babies born in the three health districts in the recruiting period.

Working mums
The major reason for the high household incomes is that the vast majority of households now include more than one earner. Here, as in other developed countries, most mothers have moved into paid work since 1972 through a combination of choice and necessity.

TV producer Lisa Taouma went back to work three months after her son Mali was born because she is passionately committed to her work in Pacific television.

"This period has been such a critical part of our work for our community representation, we had him in daycare very, very early," she says.

Onehunga dietitian Clare Wallis, as reported in yesterday's Herald, went back to work when her son Jacob was 15 months old, partly because she was "ready to go back to work at that point and use my brain in a different way", but also partly "so that we can buy a house one day".

Tan and Karsten Maertzschink had their first baby when she was 30 and he was 36.

"I wanted to complete my studies and get married and have my working life for a while, enjoy myself, and then have the baby just before 30," Tan says.

"But then it got closer to 30 and it didn't happen. We tried for about three years. I had to consult with the fertility clinic in Greenlane, they didn't find anything wrong, just unexplained infertility. Then just before they went on to the next procedure, Maximilian [the baby] came."

She went back to work after her year's parental leave because "if you take too long off it's hard to go back".

Melinda Gibbon, who had to use fertility treatment, has also gone back to part-time work after giving birth to twins.

Although the 1972 Dunedin sample of mothers had an average age of 29, the median age of all mothers giving birth in New Zealand has risen from just under 25 in the early 1970s to 30. The median age of mothers having their first babies has gone up from 23 in 1974 to 28.

A massive 89 per cent of pregnant women in the sample planned to go back to work after giving birth, on average after 14 to 15 months.

Most of those who had made childcare plans hoped their partners or other family members would look after their children (66 per cent), 39 per cent planned to use a formal early childhood centre, 15 per cent planned to look after the baby themselves while working, probably at home, and 9 per cent planned to use informal babysitters. Many planned to use several of these options.

Healthy and wise

Mothers have been able to go back to work partly because they are now highly educated. The Growing Up study has recruited a particularly well-educated sample in which 69 per cent of the mothers have post-school (Level 5+) qualifications, compared with 29 per cent of all New Zealanders aged 20 to 39.

(The study's male sample was even more skewed because it depended on the mothers giving their partners' details so only 4404 men were recruited, 73 per cent of them with post-school qualifications).

Not surprisingly, these highly educated parents are relatively well informed about how to stay healthy. Only 20 per cent of mothers smoked before they got pregnant and this dropped to 11 per cent during pregnancy. Thirty per cent did not drink alcohol even before pregnancy and this jumped to 87 per cent after the first trimester, once they were aware that they were pregnant.

More than half (58 per cent) of those who planned to get pregnant started taking folic acid before pregnancy and 84 per cent of all mothers took it while they were pregnant.

New Zealanders generally have become both better educated and more conscious of these health issues since the 1970s. Smokers have dwindled from 39 per cent of men and 31 per cent of women in the 1976 census to 23 per cent of men and 21 per cent of women aged 15 to 64 last year.

Alcohol trends are harder to track, but a survey in 2007-2008 found that 88 per cent of men and 81 per cent of women aged 16 to 64 had at least one drink in the previous 12 months.

No fixed abode

One of the most remarkable contrasts to the stable Dunedin sample is that the Growing Up families are mobile. Only 15 per cent were still in the same house they had been in five years before, 22 per cent had moved once and 63 per cent had moved at least twice.

Once again, this is a mixture of both choice and necessity. For the 40 per cent of families renting homes from private landlords, the figures point towards many being forced to move: a massive 68 per cent had moved at least twice in five years and only 5 per cent were still in the same house they started in.

But homeowners were also highly mobile, with 54 per cent moving at least twice and only 21 per cent still where they were five years ago. Presumably they were moving up to better homes or suburbs, or moving up in their careers.

Many of the moves were within the same neighbourhood. On average, the mothers had lived in their current neighbourhoods for four years. But many moves were between cities and even between countries, taking advantage of what is now a global labour market for skilled people. More than a third (36 per cent) of the mothers were born overseas and many, like the Maertzschinks, are keeping their options open to move again.

This mobility creates obvious challenges for the host society. Although the Maertzschinks deliberately speak English to their children, 20 per cent of the Growing Up families say English is not the main language spoken at home.

A third of the mothers say they "have little to do with the people" in their neighbourhood.

The Maertzschinks, living in a small cul-de-sac in Onehunga, are among the two-thirds who do know their neighbours.

Uncertain futures

Most people in 2010 have learnt to cope with frequent changes in their work and in where they live, but the bedrock of social stability is still individual relationships.

When a relationship disintegrates, as it has for Hamilton solo mum Yuanita King, everything else becomes harder.

At first glance the Growing Up sample seems to be doing okay so far. Only 5 per cent of the mothers say they had no relationship with their babies' fathers when they became pregnant, and a further 5 per cent separated or moved out of the same house during pregnancy.

But study director Dr Susan Morton is wary.

"This is pregnancy so of course somewhere there's a partner," she says.

"Over time we expect there will be a lot more change in family structure."

There are reasons to worry. The proportion of parents who are legally committed to each other through marriage or civil union has dropped from 95 per cent in Dunedin in 1972 to just 63 per cent in the Growing Up sample. A further 28 per cent are living together and 4 per cent are "dating".

Although no one knows what proportion of babies were planned in 1972, 40 per cent of those in the Growing Up study were unplanned. The study's highly-educated skew suggests that the number of unplanned babies in wider society may be higher.

On the other hand, there are some signs that society may be starting to adapt to all the economic and social changes that have hit us over these past four decades. Although unemployment has risen in the current recession, it is still far below its early-1990s peak. Sole parenthood dropped slightly in the last census for the first time since the DPB began in 1973.

The Dunedin study has been hugely valuable for social science because it is now one of the longest-running and most comprehensive human studies in the world, with 96 per cent of its original 1037 babies still returning to Otago for their interviews at age 32. Its age-38 interviews are still in progress.

Morton admits that she may not achieve such a remarkable retention rate in today's less stable world. But as most of her 6822 babies and their parents return for their interviews at nine months, at two years and regularly beyond that, she will be reporting not just on the ups and downs of those individual families. In effect, she will be delivering report cards on our society.

Tan and Karsten Maertzschink with kids Markus and Maximilian

Karsten Maertzschink is German and his wife Tan is Thai, but they choose to speak English to their sons Max, 4, and Markus, 2.

"I believe if you [immigrate] to a country you have to learn the language. If you don't use it for a time you will never be able to get it to a good level," says Karsten.

Karsten, 40, a biomedical engineer who repairs complex medical equipment, and Tan, 34, a Thai Airways check-in supervisor, exemplify the increasingly diverse parents of New Zealand's babies.

Tan came to New Zealand in 1998 to do her masters degree in management. Karsten came after finishing his degree, planning to do two months learning English and two months of work experience in a hospital. They met at an English language school and stayed.

"I think it's easier, if you're a mixed couple, to grow up in a third country," Karsten explains.

"If we were to go back to Germany it would be difficult for her, she would have to adapt to everything. If we moved to Thailand I would have to change.

"Here you can build your own life, whatever you think is right, but always having the option to go back if it doesn't turn out alright."

Tan went back to work a year after having each baby because she wanted to keep her job.

"If you take too long off it's hard to go back," she says.

Karsten adds: "You need the financial options to be able to bring up kids if they have special needs or play sport or do other activities."

The couple pay almost $500 a week for the two boys' full-time childcare. They earn too much to get subsidies and don't get the official "free" childcare for 3- and 4-year-olds because their local centre, Dynamic Kidz in Royal Oak, declined to join the 20-hours-free scheme.

But they have no complaints. "They seem to prepare the kids very well for school," says Karsten. "We are really happy."

Yuanita King with Caiden and Caiel

At the front end of the welfare system, life for Hamilton solo mother Yuanita King can be frustrating.

A former teacher, she has always budgeted carefully, gives top priority to her rent and pays her power bill in weekly instalments. But her careful planning counts against her at Work and Income.

"Food grants are difficult to get. I just recently got one, but it's very hard and it seems like it favours those who have no budgeting skills," she says.

She is learning how the system works. For example, she can only get a childcare subsidy for nine hours a week as a beneficiary, but she can get up to 50 hours if she goes back to study. She is going to Waikato University next year to do a masters degree in education, and hopes to be back teaching the year after.

Like 40 per cent of the families in the Growing Up in NZ study, King, 29, lives in a low-income area, Nawton.

Her sons Caiden, 3, and Caiel, 2, both have the same father, but he moved out early on.

"He has a few mental health issues, it was better for the children that we parted," King says.

"He comes round. It's a very cordial relationship. His mum is staying here for a week."

King copes with support from both sides of the family. Her house is owned by her partner's family, and her own parents lived in it with her until recently. She gave up the landline when she was left alone with the boys, but she can use a phone in her partner's mother's house just up the road.

"I'm feeling confident now," she says. "For a while I was a bit lost, thinking when's it going to end financially-wise - this can't be it. You just can't live from week to week on what I'm getting now.

"I had an epiphany one morning and I started running around and organising to go back to university. I have only just managed to wean Caiel and I feel a bit more free. The boys are very, very happy."

Lisa Taouma and Mario Gaoa with son Mali

Having a baby at 41 was "an unexpected blip in the career plan" for TVNZ producer Lisa Taouma.

She and her husband, bro'Town co-writer and comedian Mario Gaoa, 39, are working crazy hours on a new Pacific magazine programme, Fresh, due to debut on TV2 in January.

"This project for both of us is our big milestone project. The Pacific community has been trying for it for 20 years," she says.

"We have to ride the wave while the wave is here. We are on a huge wave, Pacific TV-making has just been born; bro'Town has led the way. They now sell advertising on TV around Pacific TV.

"So we are at the peak of our careers - and we have to factor the unexpected late-life baby into that!"

Taouma and Gaoa were together about 12 years before they married in 2007. Taouma says the baby boy who arrived a year later was never part of her plan, although Gaoa had always wanted children.

"He's been dying to breed. I haven't," she says. "I got pregnant with him on contraception at 41. So he was meant to be."

Baby Mali went into childcare at three months.

"I constantly have this lingering guilt factor about the one-on-one bonding you have with your child," Taouma says.

But her mother lives just round the corner from the couple's Kingsland home and runs a Samoan early childhood centre, Aoga Fa'asamoa. Mali spends his days at the aoga, then stays with his nana until his parents finish work, usually around 7pm.

"We work lots of weekends too," Taouma says. Mali often goes with them then and plays in a makeshift office creche created with cast-offs from the TVNZ props department.

"It's going to be intense till mid-April," his mum says.

"It's quite a pressure situation but only for 16 episodes. Our rationale with the intense work stuff is that every year we go away for a month and spend family bonding time. We're going to take May off."

Melinda and Gary Gibbon with Sasha, Jessica and Luca

When Melinda and Gary Gibbon hadn't managed to conceive a baby naturally after six months, they approached a fertility specialist.

They had already had one child, Jessica, now aged 8, who was conceived naturally. The specialist told them to keep trying for another six months.

"I was knocking on their door at six months," says Melinda, 41.

"By that time I was 35 and I didn't want the gap to get bigger and bigger between the kids. I had lots of investigations, laparoscopy and checking for endometriosis. It turned out to be secondary infertility that was unexplained. I was aware that time was ticking."

The Auckland couple tried intrauterine insemination and Melinda had fertility accupuncture and naturopathic treatment - but still no pregnancy. They gave up on fertility treatment for a time, but eventually signed up for IVF at the Repromed Auckland clinic.

Success. Melinda became pregnant with twins - Sasha and Luca, now aged 2, who are participants in the Growing Up study.

Six per cent of mothers in the study had become pregnant after having some form of reproductive treatment, mostly IVF.

The Gibbons' fertility assistance cost $36,000, including $11,000 paid by a relative for the IVF.

Owners of their Auckland home, they are happy with their family of three children, the minimum size they wanted. Melinda, a part-time client services manager for an online research and technology company, says she always wanted children, but they chose to start their family when in their early 30s because that was when their peer group started.

Gary, 42, the production manager at a printing business, says, "We would advise our children to have their children a lot sooner. You're just more energetic when you're younger. My parents and Melinda's parents were in their 20s when they had us."