This weekend’s read looks at a puzzling issue with early childhood education programs known as “fade-out.” There is plenty of evidence that preschool programs improve cognitive skills in students, but repeated studies have shown that those skill boosts often disappear after a few years of elementary school. This is now being used at times as a political argument against investing public dollars in preschool programs (like Seattle’s), suggesting that the return on investment is low. At the same time, there is little understanding of why fade-out occurs, or what might be done to sustain the skills that kids obtain in preschool. Two University of Chicago economics professors designed an experiment, in cooperation with the Chicago Heights school district, to learn more.
Their survey of several existing preschool programs shows that, indeed, in most of them the students’ cognitive skill development faded over the ensuing years. With one clear exception: the Carolina Abecedarian Project, where there was a much less pronounced fade-out and, in fact, a bit of a recovery as students moved into their teens. What was it about this one program that caused it to have a different result?
According to the researchers, “Essentially all of the Abecedarian study sample lived in the same town and attended the same public school system and continued to interact with each other.” This led them to design an experiment with preschoolers in Chicago Heights to better understand whether staying together after preschool affected students’ ability to retain skills learned in preschool.
In cooperation with the Chicago Heights Early Childhood Center (CHECC) and the local school district, as students moved out of preschool into kindergarten and beyond, the researchers randomly assigned them to classrooms and tracked their individual progress, their classmates’ progress, and, importantly, which preschool students ended up together in elementary school classrooms. Since elementary schools generally keep the kids in the same classroom all day and move teachers around (as opposed to middle school and high school, where the teachers stay put and the students move around), they were able to collect high-quality data. And they could get access to test scores and report cards to see which students saw their cognitive skills decline — and which did not.
They found that several factors had little to no effect on fade-out, despite prior speculation that they were the underlying causes:
Teacher assignment
Parental education level
Elementary school classmates’ skill levels
The number of elementary school classmates who had attended preschool
How many elementary school classmates had disciplinary or absentee issues
Researchers did, however, find one surprising correlation: Students who had at least one of their preschool classmates also in their elementary school class saw substantially less fade-out. This held true for several measures, including math assessments, reading assessments, GPA, and national standardized tests. And the association between having a preschool classmate in the same elementary class with sustained cognitive skills was even stronger for boys and for Hispanic students. Even just one “carryover” classmate made the difference.
So preschool fade-out appears to be a social phenomenon: Kids who are separated from all of their classmates when they move from preschool to elementary school lose the skills they had developed. The researchers note that this is consistent with other research showing that exposure to friends during school can improve students’ test scores, as can being in a classroom with more neighbors. Why this is so, however, is not yet understood.
This kind of surprising finding needs to be replicated before we try to act at a large scale; it may be a one-off. But it does explain why the Abecedarian Project preschool, in a very small school system, didn’t see the kind of fade-out that other preschool programs did: The kids stayed together more.
Assuming it turns out to be true, there are many important implications. First, as the researchers point out, rather than an argument against preschool, it’s a strong argument for universal preschool: It suggests that every student can benefit from preschool if they can stay together with some of their preschool classmates as they move up through elementary school. Second, it means that keeping track of students across the preschool and elementary school boundary is critically important, along with ensuring that every student stays with at least some of their preschool classmates. The logistics of that are complicated (who tracks that, and how?) but not insurmountable. Here in Seattle, the system is decentralized: The Seattle Preschool Program is run by the City of Seattle and largely funds low-income students to attend private preschools; separately, many higher-income families send their kids to private preschool. Meanwhile, the Seattle Public Schools system is a completely separate bureaucracy, independently governed, funded, and administered from the city; and, of course, there are private elementary schools as well. Ensuring that preschool classmates can stay together in elementary school, across all of those boundaries, involves information sharing but also a new, complex level of decision-making in how students are assigned to schools and classrooms.
There is also more research to be done beyond simply replicating the Chicago Heights study. We don’t understand why cognitive skill retention is dependent on students’ social networks, which means we don’t understand whether there are other ways to get the same benefit that might be simpler than trying to engineer a method for keeping preschool students together for several years.
But at least we seem to have confirmation that the problem isn’t with preschool itself; it is apparently what happens after preschool that matters.