NATIONAL RANDOMIZED TRIAL:
Montessori Education Provides Better Outcomes at Lower Cost
Boy playing stamp game in a Montessori classroom. Credit: Forest Bluff Montessori School
October 21, 2025—A groundbreaking national study published in the prestigious journal Proceedings of the National Academy of Sciences provides compelling evidence that public Montessori preschool programs produce superior educational outcomes while costing significantly less than traditional approaches.
The first randomized controlled trial of its kind, led by researchers from the University of Virginia, University of Pennsylvania, and the American Institutes for Research, tracked 588 children across 24 public Montessori programs nationwide.
The study appeared on October 21, 2025 in the journal Proceedings of the National Academy of Sciences (PNAS) (article full text).
Key Findings
By the end of kindergarten, children randomly selected to attend public Montessori preschools demonstrated:
- Significantly higher reading abilities
- Enhanced executive function
- Improved short-term memory
- Better social understanding and theory of mind
Notably, these benefits were achieved at approximately $13,000 less per child compared to traditional preschool programs.
“These findings affirm what Maria Montessori believed over a century ago—that when we trust children to learn with purpose and curiosity, they thrive,” said Angeline Lillard, Commonwealth Professor of Psychology at the University of Virginia and study lead.
Sustained Benefits
While the study found no notable impacts at the end of PK3 or PK4, by the end of kindergarten, the Montessori advantage was clear and statistically significant. This pattern contrasts sharply with typical preschool research, where initial gains often fade by kindergarten. The intention-to-treat effect sizes exceeded a fifth of a standard deviation, considered large in field-based school research.
The cost savings stem primarily from more efficient classroom structures, including higher child-to-teacher ratios in the PK3 and PK4 years. These multi-age groupings enable peer learning while requiring fewer staff resources.
“Montessori began in the low-income housing of early 20th century Rome,” noted David Loeb of the University of Pennsylvania. “This research shows it still delivers on that promise for America’s children today.”
This rigorous research provides policymakers and educational leaders with actionable evidence that Montessori’s century-old approach delivers meaningful academic and social advantages while using resources more efficiently.
Research Team
This landmark study represents the collaborative efforts of a distinguished research team including Dr. Angeline Lillard and Emily Daggett from the University of Virginia’s Department of Psychology; Dr. David Loeb from the University of Pennsylvania’s Graduate School of Education; and Dr. Jade Berg, Dr. Maya Escueta, Dr. Karen Manship, and Dr. Ashley Hauser from the American Institutes for Research.
For More Information
Study citation: Lillard, Angeline S, et al. A national randomized controlled trial of the impact of public Montessori preschool at the end of kindergarten, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2506130122
See also:
- University of Virginia News: UVA-led national study finds Montessori preschool boosts learning, cuts costs
- Dr. Lillard’s best-selling book, Montessori: The Science Behind the Genius.
- Latest Montessori research articles by Dr. Angeline Lillard.