The findings are from one of the largest and most comprehensive studies on the effect of early childcare that has followed 1,364 children from birth in the United States. The study found that both positive and negative effects of experiences in the first four or five years of life are evident at the age of 11.
Lead author Professor Jay Belsky, director of the Institute for the Study of Children, Families and Social Issues at Birkbeck College, University of London, told Nursery World, 'The more these children were in centres, the more disobedient and aggressive they were up to the age of 11.'
He said it was 'a big surprise' that the quality of childcare was not a factor, because 'there is this big idea that high-quality childcare mitigates everything.'
However, the report found that children in better quality childcare had greater language abilities, reflected in a bigger vocabulary at the age of ten, regardless of whether they were in a nursery or looked after by a childminder or nanny.
Professor Belsky said, 'It was not the type of care or the dosage, it was the quality of care.'
Researchers recruited children from birth from their families and observed them at six months, 15 months, 24, 36 and 54 months on two separate days for four hours a day. Children were counted as attending a childcare centre if they attended for at least ten hours a week.
The study also took account of the quality of parenting, family income, the quality of schooling, and depression in the mother.
Professor Belsky said, 'The effects of group care endure over and above these confounding factors. Children are more likely to be disobedient whether they are in high-quality or low-quality childcare. It looks like there is an adverse effect suggested by being in groups of children.'
Children were followed up every year during primary school and teachers were asked questions such as whether children 'kicked, punched, disobeyed or broke things'.
Professor Belsky said that it was significant that the findings of aggression and disobedience among children who had been in group care were replicated every year with different teachers.
He stressed that he was not making 'a moral judgement' but that, based on the evidence, he did not think it 'advisable' to put children in group settings.
The National Day Nurseries Association said the new research would 'needlessly' worry parents. Chief executive Purnima Tanuku said, 'NDNA does not agree that the quality of childcare is not a factor in a child's development. To say no matter how high the quality of service a child receives, he or she could grow up aggressive, is both insulting and unfair.'
The research, the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, is published in the journal Child Development, March/ April 2007.
Key points
* The longer children spend in group childcare, the more aggressive and disobedient teachers rated them up to the age of 11. Quality of childcare was not a factor.
* Positive and negative effects of childcare in the first five years remain up to the age of 11.
* High-quality childcare increased the size of children's vocabularies up to the age of ten.
