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The longer young children spend in daycare away from their mothers, the more likely they are to be overly aggressive by the time they reach kindergarten, according to the largest study of child care and development ever conducted.
"As time goes up, so do behaviour problems," said Jay Belsky, one of the study's principal investigators. He presented the findings yesterday.
The study found a direct correlation between time spent in daycare and such traits as aggression, defiance and disobedience. Two of its lead researchers said the findings held true regardless of the type or quality of care, the sex of the child, the family's socio-economic status or whether the mothers themselves provided sensitive care.
Dr. Belsky said children who spent more than 30 hours a week in daycare "are more demanding, more non-compliant and they are more aggressive."
Dr. Belsky added, "They scored higher on things like 'gets in lots of fights,' 'cruelty,' 'bullying,' 'meanness,' as well as 'talking too much,' [and] 'demands must be met immediately.' "
The study followed more than 1,300 children in 10 U.S. cities in a variety of settings, from care with relatives and nannies to preschool and large daycare centres. Its conclusions are based on ratings of the children by their mothers, those caring for them and kindergarten teachers.
The research, financed by the National Institute on Child Health and Human Development, a branch of the National Institutes of Health, has not undergone peer review.
In 1986, Dr. Belsky published an article suggesting daycare posed a risk for developmental problems. Dr. Belsky is a developmental psychologist who two years ago left Penn State University, one of the study sites, for the University of London.
"When I saw who the principal researcher was, I wasn't surprised because that's an agenda he's been pushing for awhile," said Sandra Griffin, executive director of the Canadian Child Care Federation, a non-profit organization in Ottawa.
She said research should focus on the quality of daycare, not on who the provider is.
"The quality of care in the U.S. is abysmal. If you wanted to do a good comparison group [for daycare providers], take kids who have been at home with severely stressed parents ... and those kids are going to be in trouble as well," said Ms. Griffin, who has not reviewed the study.
Thirteen million pre-schoolers, including six million infants and toddlers, are in daycare in the United States -- roughly 75% of all children that age, according to the Children's Defense Fund in Washington.
In Canada, close to 1.4 million children are in paid daycare services. Roughly 30% of Canadian mothers with children under age six remain at home, the Canadian Child Care Federation says.
The researchers did not have an explanation for why some children in daycare might become more aggressive or disobedient.
But they do have some theories: Daycare providers may not be trained to give emotional support, suggested Dr. Sarah Friedman, project co-ordinator.
The researchers will continue to track the children. They cautioned against drawing conclusions that children in daycare would turn out to be violent.
Dr. Friedman said the children's behaviour, while demanding and aggressive, was "in the normal range," and did not require medical attention.
The study began in 1990 in 10 cities. It defined daycare as supervision by anyone other than the child's mother that was routinely scheduled for at least 10 hours per week.
When the researchers examined behavioural ratings for children who were in care for more than 30 hours per week, they found 17% were regarded by teachers, mothers and caregivers
as being aggressive toward other children. That is compared with 6% for the group of children in daycare for less than 10 hours a week.
Children who spent more time in care were initially rated as being more fearful and sad than other children, but the differences disappeared by kindergarten.
Children who spent more time in daycare, as opposed to other types of child care, in the first 4 1/2 years of life were more likely to display better language skills and have better short-term memory. The researchers said they had not determined if these children were the same ones who were at increased risk of behavioural problems.
-Reprinted from The National Post