By the time New Zealand children turn two, 80 per cent are regularly in a room with a TV on all the time, according to a groundbreaking survey tracking almost 7000 children from birth to 21 years old.
Of those 80 per cent, about two-thirds spend between one and three hours a day watching TV while the other third do so for more than three hours a day.
Around 15 per cent are regularly using a computer or laptop by the age of two. By the time they get to four and half, that figure is far higher although final data is yet to be collated. About 66 per cent have a book read to them daily.
The Growing Up in New Zealand longitudinal study, headed by Associate Professor Susan Morton at the University of Auckland, has followed the children since they were born five to six years ago, in the Waikato, Auckland and Counties-Manukau District Health Boards regions. It will continue to do so until they turn 21.
The key factor in the TV-watching data is this is the first time researchers have begun to monitor the effects of such exposure on the very young.
Morton says: "Prior research has usually reported screen time for children who are over 5 years of age. Linking screen time with later anti-social behaviour has been based on older children watching TV in the main part. So this provides new information about how ubiquitous screen time is for this new generation of children from a very early age."
Previous studies, both in New Zealand and overseas, have linked increased screen time to poorer social interaction, more hyperactivity and more criminality as children get older. Morton says ongoing research is needed to determine long-term effects.
The children being surveyed are from a broad reach of socio-economic status, rural/urban living and ethnic origins from the above regions.
But it's already clear from the study that Kiwi children are growing up in a vastly different world from a generation ago and policy makers will need to adjust rapidly to the change.
Morton, director of the study, says it's a world where half of our children live in rented houses, many on the poverty line, and many with a parent from a foreign country; where children spend hours watching TV or other electronic screens, rather than reading books.
A change in family structure has also shown up, with only 5 per cent of the children in the study living with a single parent at the age of two - previously the numbers were far greater. This generation of children are more likely to be raised in an extended family of aunties, uncles, grandparents or adults unrelated to the child.
Poverty - affecting about 40 per cent of the children surveyed - is another issue. During the 90-minute interviews, researchers ask each family if they have had to make decisions such as going without fruit and vegetables, not using heating because of lack of money to pay power bills or not replacing shoes and clothing.
At least half reported making one of those decisions in the first year of the children's lives. Morton says: "It suggests there is a lot of hardship out there for families with young children."
Almost one in two children are growing up in rental accommodation, with only a small proportion living in state housing. It is highly unlikely many families will be able to buy their own homes, with Morton saying: "Most seem to be heading for almost lifelong rental."
As a result, many families tend to move around a lot, making it harder to keep tabs on the children in terms of vital immunisation and health checks. Agencies may assume, if people don't respond or don't turn up to an appointment, it was their choice not to attend, she says.
"It's often not because they don't want to, it's because they haven't been found. These people are highly mobile and have chaotic and challenging conditions they are dealing with on a daily basis."
Morton says 98 per cent of the mothers surveyed wanted their children immunised when interviewed during pregnancy.
"Yet by the time the children get to two, we see huge disparities in terms of ethnicity, socio- economic status and rates of achieved immunisation."
Diversity of cultures is also evident in the study, with a third of the children having at least one parent born overseas and a total of more than 90 languages spoken across surveyed homes.
Morton says findings from the study, funded by the university and 16 government agencies, will be regularly passed on to policy makers throughout the two decades to help give New Zealand children the best outcomes.
"The information can help to bridge the gap that often exists between the policy table and the family table," she says. "It can help policymakers understand why some policies appear to be working well and others do not seem to be having the desired effect.
"This can help to ensure policy accurately targets those most in need."