No Link between Daycare and Toddler Aggression

Many working parents dread leaving their children in daycare as they believe the interaction with other toddlers may lead to undesirable behaviors.

A new study may alleviate at least some of the fears as researchers tracked almost 1,000 Norwegian children and found the amount of time children spent in daycare had little impact on aggressive behavior.

The study is published in Psychological Science, a journal of the Association for Psychological Science.

“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,” says Eric Dearing, lead author on the study and a psychological scientist at the Lynch School of Education, Boston College.

However, the fear of daycare is not unfounded.

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.

These findings continue to provoke uncertainty and fear among parents as the debate over the effects of daycare are ongoing.

“Three decades of follow-up studies have only further fueled this debate,” Dearing explains. “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.”

Dearing and colleagues from the Norwegian Center for Child Behavioral Development, Henrik Daae Zachrisson and Ane Nærde, determined that Norway’s child care practices offered a unique opportunity for empirically addressing this controversy.

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 centers begin enrollment in August, children typically enter child care at different ages depending on what time of year they were born. For example, a child born in August would enter daycare at 12 months old, while a child born in February would be 18 months old by the time August enrollment opened.

The researchers were able to use this as a natural randomizer; 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 behaviors 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 explains.

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. Importantly, these differences in physical aggression diminished over time — regardless of how much time children spent in daycare.

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

“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,” the researchers write.

Given the evidence that early child care is not associated with problems with aggression, the researchers are turning their attention to the potential positive effects that daycare may have for children’s language development and learning.

Source: Association for Psychological Science
Aggressive young boy photo by shutterstock.