In 1962, researchers in Michigan began the Perry Preschool Project. The project provided an intensive childcare program to 58 children from low-income families. The program featured a low teacher-student ratio, and a weekly home visit. Researchers tracked the life outcomes of participants, and compared them to a control group.

The results were striking.  On average, participants had a higher high school graduation rate, were less likely to have been arrested, and earned significantly more money than control group members.

Researchers have raised concerns about whether these results can be generalized. The initiative was a “hothouse” program with just 58 students, high per-student costs, and an extremely committed and experienced teaching team. It’s not clear whether it is feasible to “scale up” this type of program. Furthermore, the program targeted economically disadvantaged students, a group that experiences (on average) much greater developmental benefits from childcare interventions than other children. In fact, several studies suggest that cognitive benefits of childcare participation for middle-class children generally “fade out” almost entirely by entry into Fourth Grade.

With these caveats noted, the Perry Preschool Project was nonetheless an important research project. It provided compelling evidence that certain types of childcare interventions can bring substantial, long-lived advantages to children in specific circumstances.

However, new research suggests that the opposite can also be true—that certain types of childcare interventions can bring substantial, long-lived disadvantages to children. In 2008, a team of researchers from the University of Toronto, MIT and UBC published an influential study analyzing the impact of Quebec’s “universal” childcare program on maternal labour supply and child development outcomes. The researchers found that the program achieved one of its objectives—boosting maternal labour force participation. This aligns with the findings of other studies, which found subsidized childcare increases employment rates and government revenues.

However, the study also found that the program produced, across a range of indicators, substantive negative health and behavioural development effects for children.

Recently, the same team published a follow-up working paper  (not yet peer-reviewed) that concluded these outcomes were long-lasting. Years later, the program has resulted in higher crime rates (among boys) and higher levels of hyperactivity and aggression. Girls exhibited lower tendencies towards prosocial behaviors including volunteer work and charitable giving. These findings cast doubt on the notion that large-scale, universal childcare programs such as Quebec’s are a panacea to economic and social problems.

Neither the research in Quebec nor the results of the Perry Preschool Project are the final word on childcare and development outcomes. They (and other research) should be considered together, and lead us to recognize that our understanding of these matters remains incomplete. Despite claims from activists that “the evidence shows” subsidized childcare will bring long-lasting benefits to children, the reality is that the evidence is mixed. Just as skeptics of childcare subsidies must accept the results of the Perry Preschool Project, proponents should not reflexively dismiss the research from Quebec simply because it does not advance their agenda. To state what should be obvious—the socialization of children is a complicated subject that we don’t understand with the type of scientific precision that some childcare activists suggest.

The research from Quebec raises valid questions about whether that province’s model is one that the rest of the country should emulate, and should at least give us pause before rushing into a “one-size-fits-all” solution. Instead, families and communities should be encouraged to experiment, and pursue arrangements that suit them best while researchers continue the important work of furthering our understanding of how different types of childcare programs can influence child development.