This created a predicament: Policies that favored working mothers seemed to be placing their children at a disadvantage. In fact, it’s the same argument President Nixon cited in 1971 when he vetoed the Comprehensive Child Development Act, which almost granted universal child care in the United States. Nixon described the bill as “a long leap into the dark,” fearing that “it would commit the vast moral authority of the national government ... against the family-centered approach.”

Ivanka Trump had nearly the opposite to say on the campaign trail in 2016. “As a society, we need to create policies that champion all parents, enabling the American family to thrive,” Trump said to a crowd in Aston, Pennsylvania. For all its complications, child care is often surrounded by two modes of thought: On the one hand, policy-makers argue that families do best when the parents are successful, supporting the case for more readily available child care. On the other hand, they argue it’s the child’s well-being that matters the most, and children benefit from increased parent attention. Are the two beliefs mutually exclusive?

The authors of another NBER working paper, released Monday, revisited Quebec’s child-care policy to determine whether any additional effects are at play. What they found was striking: Not all children with access to universal care exhibited similar responses. After studying children under the age of 5 from two-parent families, the researchers found a distinctly gendered difference in the way children were shaped by universal care. Only boys, for instance, saw a significant decline in motor social development, as well as increased hyperactivity and inattention. By contrast, only girls saw significant increases in emotional and separation anxiety. (Formal tests did not reveal significant gender differences on average.)

Perhaps the most interesting finding was that parents raised their children differently depending on their access to subsidized care. “The introduction of universal child care led to substantial changes in the manner in which parents invested in sons and daughters,” the researcher wrote. To start, boys were more likely to be placed in center-based care, while girls were more likely to be placed in home-based care. Girls with access to universal child care also experienced fewer positive interactions with their own parents. Notably, the parents of girls were two times less likely to spend time reading to, laughing with, or doing special activities like going to the library with their child.

As is often the case, future research is needed to determine whether these gendered differences have lasting effects as children become adults. It’s also important to point out that the poor quality of Quebec’s day-care program likely has something to do with its negative effects.