Working parents worried about sending their toddlers to daycare can breathe a sigh of relief as a new study has found that the amount of time children spend in daycare has little impact on aggressive behaviour.
The study tracked almost 1,000 Norwegian children enrolled in daycare and found that modestly higher levels of aggression observed in younger toddlers in child care diminished over time regardless of how much time they spent in day care.
"From a public perspective, our findings are important because they should help ease parents' fears about the potential harms of early non-parental child care," said lead author Eric Dearing, psychological scientist at the Lynch School of Education, Boston College in US.
As women entered the workforce in increasing numbers in the 1980s, some child development researchers began reporting that daycare had harmful consequences for children's social and emotional adjustment, researchers said.
These findings stoked uncertainty and fear among parents, and led to debate among researchers in the field.
"While some studies indicate that beginning care early in life and attending for long hours leads to high levels of behaviour problems, such as elevated aggression, other studies indicate no risk associated with child care," Dearing said.
Dearing and colleagues from the Norwegian Centre for Child Behavioural Development, Henrik Daae Zachrisson and Ane Naerde, determined that Norway's child care practices offered a unique opportunity for empirically addressing the debate.
In Norway, most parents have up to a year of parent leave, so children in Norway rarely start attending daycare before they are nine months old.
Because publicly funded child care centres begin enrolment in August, children typically enter child care at different ages depending on what time of year they were born.
The researchers used this as a natural randomiser - a child's birth month, rather than their parents' preferences, determined what age they started going to daycare.
Trained assistants interviewed parents of 939 children about time spent in daycare at ages six months and one, two, three, and four years old. Each year, the child's daycare teacher reported on aggressive behaviours like hitting, pushing, and biting.
"One surprising finding was that the longer children were in non-parental care, the smaller the effects on aggression became," Dearing said.
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.
These differences in physical aggression diminished over time - regardless of how much time children spent in daycare.
"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 centre care thereafter, may help prevent such an outcome," the researchers said.
The study was published in the journal Psychological Science.
