The question is deceptively simple: Is preschool worth it? Parents asking this question usually mean several things at once. Will it help my child academically? Is it worth the cost? Will my child be okay if they don't go? The research on early childhood education spans six decades and includes some of the most carefully designed studies in all of social science. The answers, as with most things involving children, are more nuanced than the headlines suggest.
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The Studies Everyone Cites
Three landmark studies form the foundation of what we know about preschool's long-term effects:
The Perry Preschool Project (1962-1967)
In Ypsilanti, Michigan, 123 low-income African American children were randomly assigned to either attend a high-quality preschool program or receive no preschool. Researchers followed these children for decades. By age 40, those who attended preschool had higher earnings, were more likely to own homes, and were less likely to have been arrested. The program's return on investment—calculated by economist James Heckman—has been estimated at 7-12% annually, driven largely by reduced costs to the criminal justice system and increased tax revenue from higher earnings.
The Abecedarian Project (1972-1985)
This North Carolina study was even more intensive: children from low-income families received full-day, year-round educational childcare from infancy through age 5. The results were striking. Participants scored higher on cognitive tests, were more likely to attend college, and showed better health outcomes into their 30s. A 2021 follow-up found that children of the original participants also showed benefits—the effects appeared to transfer across generations.
The Chicago Child-Parent Centers (1967-present)
This program served low-income children in Chicago public schools, providing half-day preschool along with parent involvement activities. A longitudinal study following nearly 1,500 children found that participants had higher rates of high school completion, lower rates of juvenile arrest, and fewer instances of child maltreatment. By age 35, the economic return was estimated at $10.83 for every dollar invested.
These studies share important characteristics: they all served low-income children, they all provided high-quality programming, and they all showed effects that persisted long after the programs ended. They form the empirical foundation for public investment in early childhood education.
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The Fade-Out Problem
Here's where the story gets more complicated. Many studies of preschool programs find that academic gains measured at kindergarten entry diminish over time—sometimes disappearing entirely by second or third grade. This phenomenon, called "fade-out," has troubled researchers and given ammunition to preschool skeptics.
The Tennessee Pre-K study, published in 2022, followed children who had been randomly assigned to the state's voluntary pre-kindergarten program. Initial results showed positive effects on academic skills at school entry. But by sixth grade, children who had attended the program actually performed slightly worse on some measures than those who hadn't. The finding sent shockwaves through the early childhood field.
How do we reconcile these results with the landmark studies showing lasting benefits? Several factors matter:
Quality Varies Enormously
The Perry, Abecedarian, and Chicago programs were exceptionally high-quality—small classes, well-trained teachers, intensive support. Many state pre-K programs operate at much lower levels of quality, with larger classes, less-trained staff, and fewer resources. The research is clear: quality matters at least as much as access.
What Happens After Matters Too
If children attend excellent preschool but then enter poor-quality elementary schools, early gains may not be sustained. The landmark studies that showed lasting effects often included ongoing support into the early elementary years. Preschool alone may not be enough if the educational quality drops off afterward.
Academic Skills Aren't Everything
Test scores may fade, but social-emotional skills, self-regulation, and attitudes toward learning may persist in ways that don't show up on standardized assessments. The long-term benefits found in Perry, Abecedarian, and Chicago—higher earnings, lower incarceration rates, better health—weren't predicted by test scores alone.
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The Boston Study: A More Encouraging Picture
A 2021 study from MIT examined Boston's public preschool program, which prioritizes quality and serves a diverse population. Researchers used a lottery system to compare children who won seats in oversubscribed programs to those who didn't.
The results diverged from Tennessee in important ways. Children who attended Boston's preschools showed improvements in social-emotional skills, reductions in special education placement, and—for those who remained in Boston public schools—higher rates of graduating high school, attending college, and taking the SAT.
The researchers noted that Boston's program emphasized social-emotional development alongside academics, maintained smaller class sizes, and employed teachers with stronger qualifications than Tennessee's program. Quality, again, appeared to make the difference.
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What About Middle-Class Families?
Most of the landmark research focused on low-income children, who showed the largest benefits. The picture for middle-class families is less clear—not because preschool doesn't help these children, but because they often have enriching alternatives: parents who read to them, books in the home, educational activities, and high-quality informal care from relatives or nannies.
For families where children already have access to rich learning environments, preschool may offer smaller academic advantages. This doesn't mean it's without value—the social experience, the exposure to diverse peers, and the practice with classroom routines all matter. But the gap between attending and not attending is smaller when "not attending" still involves significant learning opportunities.
Research from Denmark—where nearly all children attend high-quality, subsidized childcare—suggests that universal preschool can reduce inequality by providing similar experiences across income levels. The benefit may be less about absolute gains for any individual child and more about ensuring all children enter school on similar footing.
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What the Research Actually Tells Us
Synthesizing six decades of studies, here's what we can say with reasonable confidence:
High-quality preschool benefits children, especially those from disadvantaged backgrounds.
The evidence for this is strong and consistent across multiple studies using rigorous methods.
Quality matters more than access.
A mediocre preschool program may provide few lasting benefits. The factors that define quality—teacher-child interactions, ratios, teacher qualifications—are more important than simply whether a child attends any program.
Academic gains may fade; other benefits may not.
Test score improvements often diminish over the elementary years. But social-emotional skills, attitudes toward learning, and longer-term outcomes like high school graduation and college attendance may persist.
What happens after preschool matters too.
Early gains are more likely to persist when followed by continued high-quality education. Preschool is a foundation, not a magic bullet.
The alternative to preschool matters.
For a child who would otherwise spend the day in a chaotic or unstimulating environment, preschool offers major advantages. For a child with a highly enriching home environment, the marginal benefit is smaller.
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Making the Decision for Your Family
The research can inform your decision, but it can't make it for you. Here are the questions that matter:
What is the quality of the programs available to you?
A high-quality program is more likely to benefit your child than a low-quality one. Use the evaluation criteria in our companion articles to assess the options in your area.
What is the alternative?
If your child would otherwise be in a rich, stimulating environment—whether with a parent, relative, or high-quality nanny—the case for preschool rests more on social exposure and school readiness than on cognitive development. If the alternative is less enriching, preschool's benefits are likely larger.
What does your child need?
Some children thrive on the structure and social environment of preschool. Others may be better served by another year of smaller, more individualized settings. There is no evidence that children who start formal schooling at 4 outperform those who start at 5 or 6 in the long run; developmental readiness varies.
What does your family need?
The question of whether preschool "is worth it" often includes practical considerations: parent work schedules, family finances, childcare logistics. These factors are real and legitimate. Research can't tell you how to weigh them against each other.
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The Honest Answer
Is preschool worth it? For most children, in a high-quality program, the answer is probably yes—with the largest benefits going to children who have the fewest other enrichment opportunities. But the research doesn't support the idea that preschool is essential for all children, or that skipping it will put your child at a permanent disadvantage.
What matters most is not the label on the setting but what happens within it: warm, responsive interactions with adults; opportunities for play and exploration; exposure to language and books and ideas; practice with the social and emotional skills that enable learning. These things can happen in preschools. They can also happen in homes, in family childcare settings, in informal play groups.
The early years matter—the science on that point is clear. But there is more than one path through them.
Sources
- Schweinhart, L.J., et al. "The High/Scope Perry Preschool Study Through Age 40." High/Scope Press, 2005.
- Heckman, J.J., et al. "The Rate of Return to the HighScope Perry Preschool Program." Journal of Public Economics, 2010.
- Campbell, F.A., et al. "Early Childhood Investments Substantially Boost Adult Health." Science, 2014.
- García, J.L., et al. "The Dynastic Benefits of Early Childhood Education." NBER Working Paper, 2021.
- Reynolds, A.J., et al. "Age 26 Cost-Benefit Analysis of the Child-Parent Center Early Education Program." Child Development, 2011.
- Durkin, K., et al. "Effects of a Statewide Pre-Kindergarten Program on Children's Achievement and Behavior Through Sixth Grade." Developmental Psychology, 2022.
- Gray-Lobe, G., Pathak, P.A., & Walters, C.R. "The Long-Term Effects of Universal Preschool in Boston." NBER Working Paper, 2021.
- Phillips, D.A., et al. "Puzzling It Out: The Current State of Scientific Knowledge on Pre-Kindergarten Effects." Brookings Institution, 2017.
- Yoshikawa, H., et al. "Investing in Our Future: The Evidence Base on Preschool Education." Society for Research in Child Development, 2013.
- Cascio, E.U. "Does Universal Preschool Hit the Target? Program Access and Preschool Impacts." Journal of Human Resources, 2021.