Daycare does not make pre-school children aggressive

A study of 1,000 Norwegian pre-school children, that surveyed children attending daycare at various ages, found that the amount of time children spend in daycare has little impact on children’s aggressive behaviour.

The debate over whether daycare leads to behavioural problems has raged among academics for more than 30 years.

Since the 1980s, when women increasingly started to return to work after giving birth, some child development experts have warned that daycare can affect children’s social and emotional development.

Academics such as Professor Jay Belsky have argued that early childcare can pose a developmental risk for aggression and other problems.

Longitudinal studies that started in the 1990s  - such as the NICHD Early Child Care Research Network - have suggested that long amounts of time in any form of non-maternal care during a child’s early years increase the risk for aggression and other problems.

Psychological scientist associate professor Eric Dearing from Boston College, lead author of the study, said, ‘Three decades of follow-up studies have only further fueled this debate.

‘While some studies indicate that beginning care early in life and attending for long hours leads to high levels of behavior problems, such as elevated aggression, other studies indicate no risk associated with child care.’

Professor Dearing and colleagues from the Norwegian Centre for Child Behavioural Development at the University of Oslo, Henrik Daae Zachrisson and Ane Nærde, followed 939 children from six months to four years attending Early Childhood Education and Care centres.

In Norway most parents have up to a year of parental leave and children enroll in childcare in August, but start at different ages depending on when they were born.

The researchers used this as ‘a natural randomizer’, because a child’s birth month, rather than their parents’ preferences, determined when they would start daycare. So, for example, a child born in August would start at 12 months, but a child born in February would be 18 months old at the time of the August enrollment.

Researchers interviewed parents about their child’s time in daycare at six months and then at one, two, three and four years of age.

Each year the child’s daycare provider would report on signs of aggressive behaviours, such as biting, hitting, pulling hair, pinching and pushing, whether towards other children or adults.

When the children were two-years-old, those who had entered at earlier ages displayed modestly higher levels of aggression than peers who entered later. But, importantly the researchers say, these differences in physical aggression diminished over time - regardless of how much time children spent in daycare.

The authors concluded, ‘If early, extensive, and continuous non-parental care does, in fact, cause high levels of aggression in children, this study suggests that one-year of parental leave, and entry into high-quality center care thereafter, may help prevent such an outcome.’

In fact, spending time with other adults actually improved behaviour.

Professor Dearing said, ‘One surprising finding was that the longer children were in non-parental care, the smaller the effects on aggression became.’

‘At age two, there was some evidence of small effects of early, extensive, and continuous care on aggression,’ Professor Dearing added. ‘Yet, by age four - when these children had been in childcare for two additional years  - there were no measurable effects of childcare in any of our statistical models. This is the opposite of what one would expect if continuous care was risky for young children.’

• ‘Age of entry into early childhood education and care as a predictor of aggression: faint and fading associations for young Norwegian children’ is published in Psychological Science.