Nearly half of the mothers of 7000 preschoolers in a big Government study live in rented homes and move often.
The study, Growing Up in New Zealand, found 50 per cent of the four-year-olds had moved homes at least once from the age of two. Increasing numbers of children were living with a single parent, the research shows.
Maori children were more likely to live with a sole parent than any other ethnic group while Pacific households were most overcrowded.
The University of Auckland research found one in five mothers experienced depressive symptoms during or since pregnancy and that by age four, nearly all the children spent time away from their parent in an early childhood setting.
The latest findings have been released as part of the Now We Are Four segment of the research, which began in 2008 following 7000 children to the age of 21.
The study aims to find out what shapes a child's early development and how interventions could best be targeted. Last year the study was reportedly cut to 2000 children.
The multi-million dollar study is funded by the Government and managed by agency Superu (formerly the Families Commission).
Families Commissioner and chair of the Superu Board, Len Cook, said the effect of rental accommodation on families needed further exploration.
He said Pacific households appeared to bear the most significant effects of overcrowding with half of all Pacific four-year-olds sleeping in a room with adults.
Cook said with families moving frequently it raised questions around what impact that was having on healthcare and early childhood education services as well as ensuring places in local schools.
Single parenting had implications for services supporting sole parents and their children, as previous research showed single-parent households faced greater financial stress.
"There is a clear need to address this," Cook said in the report.
Now that children were mostly in early childhood education it meant a shift in family dynamics as mothers went back to work, Cook said.
"We see greater employment of mothers, leading to improved economic circumstances for these households."
Cook said there was still a lot to learn about this group of children as they grow and Superu had made more than $1 million in funding available in 2017 to fund policy-relevant research using the Growing Up in New Zealand data.
Research director Associate Professor Susan Morton said it was reassuring to see the majority of the cohort of children were thriving, often in the face of adversity.
The next report to be released later this year is Transition to School where early analyses shows some of the most vulnerable children are missing out on the important Before School Check (B4SC).
• 14 per cent of the children were overweight or obese.
• Only a quarter of children chose to do active things versus a third who chose inactivity in their free time.
• Most of the children were getting the recommended 10-13 hours sleep a night.
• One in eight had never been to the dentist by age four. This was higher for Maori and Pacific children at one in five.
• Four out of five were regular media users, with an average screen time of two hours a day.
• Overweight and obese children had higher screen time than children of
• 69 per cent lived in households where there were rules around how much TV, computer and DVD time was allowed.
Diet and Medication
• 54 per cent were eating at least two servings of fruit and vegetables each day.
• 43 per cent ate lollies and chocolate up to twice a week, 27 per cent up to six times a week and 12 per cent every day.
• Six out of seven children were fully immunised by the age of four.
• 26 per cent of parents reported concern about the risk of side effects and complications from immunisations as the reason for their child not to be immunised.
Behaviour and Emotions
• 96 per cent of the cohort were kind to younger children and 93 per cent were considerate of other people's feelings and helpful if someone was hurt.
• Only 1 per cent were consistently not well-behaved while one in two of all children were reported as being "nervous or clingy" in all new situations.
• 91 per cent of children could recognise the emotion happy, and 85 per cent sad.
• Fewer than one in five children were able to recognise the more subtle facial emotions of surprised or scared.
• 72 per cent of children showed self-control when asked not to "peek" during a gift-wrapping task.
Language and Communication
• 26 per cent of children were never or rarely able to communicate in a clear and logical way.
• 80 per cent of children were often understandable when talking to other adults not in their family.
Family and Whanau
• 99 per cent of mothers always or very often express affection for their child.
• 12 per cent of parents reported not knowing how to discipline their child.
• Only two thirds of mothers reported that they never used physical punishment.
• One in 10 parents said they frequently smacked.
Good life is there for Amelia
Amelia Mackenzie-Fellingham is your average Kiwi kid.
The 4-year-old watches a bit of Netflix on her parents' iPad, eats a few lollies at birthday parties, loves fruit, does gymnastics and swimming, and rides her bike with trainer wheels up and down the cul-de-sac where she lives.
Mum Philippa Mackenzie said Amelia, who turned four in April, isn't allowed to watch YouTube and her iPad use, about 90 minutes a day stretched over morning and afternoon, is carefully monitored.
Amelia, whose older half brother and sister visit every second weekend, is in to role playing using her new dolls house.
She's been to the dentist twice and had her B4 school check but Amelia's GP visits are often a waste of time according to Mackenzie who said her daughter refuses medication.
"I'll only take her if she has sore ears because I know how painful that can be."
Just like many other preschoolers Amelia refuses a lot of vegetables, but seems happy to eat carrots and corn.
The youngster lives with her mum and dad Darryl Fellingham, and goes to Playcentre and Kindergarten twice a week each.
She will probably go to St Joseph's Catholic School in Hamilton when she turns five but school isn't even on her radar yet, Mackenzie, 39, said.
Amelia, tall and lean for her age, goes to bed and is usually fast asleep by 7pm, waking about 6am most days, Mackenzie said.
One of Amelia's favourite past times is to visit her Nana, Poppa and 94-year-old great grandmother, who conveniently live next door.
Mackenzie said her daughter has a "pretty good preschool life".
"She certainly doesn't miss out on much."