Time spent in childcare little cause for concern

Research on the consequences of early childcare for children's development can seem confusing, if not contradictory. On the one hand, high-quality childcare is associated with good learning and achievement outcomes. On the other hand, as little as 20 to 30 hours a week of childcare has been associated with problem behaviours such as aggression. Are we to believe, therefore, that early childcare leads children to grow up smart, but unkind?

The short answer is no: while evidence continues to mount regarding the learning benefits of quality childcare, especially for socially disadvantaged children, recent evidence gives good reason to be sceptical of the notion that childcare causes problem behaviours. In a series of studies in Norway, we are finding that giving attention to children outside of the US and being careful to disentangle what childcare truly causes from what it is correlated with is helping to clarify this point.

Starting in the early 1990s, childcare researchers in the US followed nearly 1,400 children from childbirth through adolescence. The study was motivated in part by fears that care arrangements other than maternal care might be harmful to children, especially if non-maternal care occurred early in infancy and for extended periods of time. In fact, study results indicated that children in extensive hours of childcare during infancy and toddlerhood showed somewhat higher aggression than children who remained home with their mothers. Although children in full-time childcare did not display aggression that was severe enough to be clinically worrisome, the findings gathered much attention from the media, parents, and early educators.

This US study was groundbreaking, but two of its limitations are worth noting. First, the US is somewhat peculiar when it comes to family and child policy; for example, the US is one of the only wealthy countries without federal policy providing paid parental leave. In contrast, Norway provides up to one-year of paid leave for parents and, beginning at age one, high-quality publicly funded childcare is universally available. Second, all studies to date on the potential harms of childcare have been correlational; it is not at all clear that childcare actually caused higher aggression.

Within Norway, our results are challenging those from the earlier US work indicating childcare is a risk for bad behaviour. One reason we get different results might be that childcare in the first few months of life is not uncommon in the US, but it is very uncommon to start care before nine months in Norway. However, an alternative explanation for the difference in results is our extensive attention to causality in the Norwegian studies.

In Norway just as in the US, there is a modest correlation between the number of hours a child is in childcare and aggressive behaviour, when comparing children from different families. Yet when we compare siblings who attend care for different numbers of hours during early childhood, we see no connection between childcare and aggression. Similarly, when we follow children over time as their hours in childcare changes, we find no corresponding changes in aggression. These findings have indicated that even large quantities of childcare in Norway do not cause aggression, but in our most recent work we find even better evidence of this.

In Norway, the month children are born helps determine how old they are when entering childcare, because enrolment occurs in August of each year with a priority for children who are one year of age (children born in July are likely to enter childcare at 13 months, while children born in June are likely to enter at 14 months). Taking advantage of this, we find that children who entered care as early as nine months of age are no more aggressive than children who enter more than a year later. In fact, between age two and four years, aggression levels dropped lower and lower for children who entered childcare at the youngest ages.

Our work in Norway should help ease concerns over childcare as a potential risk for problem behaviours. While continued international work on this topic is critical for understanding the relevance of policies such as paid parental leave, it is also critical that cause and effect be disentangled. The more scrutiny we have given to causality, the less evidence we find that high-quality childcare poses risks to children. Policy leaders and early educators can be confident that increasing efforts to ensure high-quality childcare will benefit children and society.

Further reading

• ‘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.
  'Daycare does not make pre-school children aggressive'
• 'Little Evidence That Time in Child Care Causes Externalizing Problems During Early Childhood in Norway', Child Development