Research on Montessori Education

What peer-reviewed studies have found about Montessori education, and where the evidence is still thin

Good to Know. Researchers have compared Montessori and conventional schooling for decades. Most studies compare families who chose Montessori with families who did not, which makes it hard to separate the effect of the school from the effect of the family. A smaller number used admission lotteries or random assignment, which handle that problem better. Each summary below says which kind of study it was.

Academic Outcomes

Lillard and Else-Quest (2006)

Evaluating Montessori Education, Science 313(5795), 1893-1894. Children who won a lottery seat at one public Montessori school in Milwaukee were compared with children who lost the lottery.

At age 5, the Montessori group scored higher on reading and math tests and on measures of executive function and social reasoning.
At age 12, reading and math scores were similar. Montessori students wrote more creative essays and chose more positive responses to social dilemmas.
With one school and a small sample, the results can’t be generalized to Montessori schools as a whole.

Dohrmann et al. (2007)

High School Outcomes for Students in a Public Montessori Program, Journal of Research in Childhood Education 22(2), 205-217. Milwaukee high school graduates who had attended public Montessori programs from preschool through grade 5 were compared with a group matched on gender, income, race and ethnicity, and high school.

The Montessori group scored significantly higher on tests linked to math and science.
There were no significant differences in English and social studies or in grade point average.
Students were matched, not randomly assigned, so the study shows an association rather than a proven effect.

Courtier et al. (2021)

Effects of Montessori Education on the Academic, Cognitive, and Social Development of Disadvantaged Preschoolers, Child Development 92(5), 2069-2088. Disadvantaged children in a French public school were randomly assigned to conventional or Montessori classrooms. The Montessori classes were adapted to the public system, with fewer materials, shorter work periods and limited teacher training.

In kindergarten, Montessori children outperformed their peers in reading.
Results in math, executive function and social skills were comparable between the two groups.

Lillard et al. (2025)

A National Randomized Controlled Trial of the Impact of Public Montessori Preschool at the End of Kindergarten, PNAS 122(43), e2506130122. Children who applied at age 3 to one of 24 public Montessori schools were compared by lottery result, with 242 offered a seat and 346 not offered one.

There were no notable differences at the end of the first two preschool years.
By the end of kindergarten, children offered a Montessori seat scored significantly higher in reading, short-term memory, theory of mind and executive function.
A cost analysis suggested three years of public Montessori preschool cost less per child than the traditional programs.

Randolph et al. (2023)

Montessori Education’s Impact on Academic and Nonacademic Outcomes: A Systematic Review, Campbell Systematic Reviews 19(3), e1330. A systematic review and meta-analysis of 32 studies comparing Montessori with traditional education.

The average effect favored Montessori, at 0.24 standard deviations across academic outcomes and 0.33 across nonacademic outcomes.
Executive function (0.36) and creativity (0.26) had moderate-quality evidence. Social skills and students’ experience of school were rated low-quality evidence.
Effects were larger in randomized studies, in preschool and elementary settings, and in private rather than public Montessori schools.

Lillard (2012)

Preschool Children’s Development in Classic Montessori, Supplemented Montessori, and Conventional Programs, Journal of School Psychology 50(3), 379-401. Preschoolers in high-fidelity Montessori classrooms, Montessori classrooms that added conventional school activities, and conventional programs were tested at the start and end of one school year. Children were not randomly assigned.

Children in the high-fidelity classrooms started out no better but gained more over the year in executive function, reading, math, vocabulary and social problem-solving.
The study suggests that how closely a school follows the method matters.

Rathunde and Csikszentmihalyi (2005)

Middle School Students’ Motivation and Quality of Experience, American Journal of Education 111(3), 341-371. About 290 demographically matched students from Montessori and traditional middle schools reported how they felt at random moments of the day using the Experience Sampling Method.

During academic work, Montessori students reported more positive mood, energy, intrinsic motivation and flow.
Traditional students rated their academic work as more important, often alongside low intrinsic motivation.
In informal, nonacademic activities, the two groups reported similar experiences.

Demangeon et al. (2023)

A Meta-Analysis of the Effects of Montessori Education on Five Fields of Development and Learning, Contemporary Educational Psychology 73, 102182. A meta-analysis of experimental and quasi-experimental studies of preschool and school-age children.

The clearest positive effects were on social skills and academic results, according to the authors’ own summary.
Effects on cognitive skills such as memory, attention and planning were very slight, and the small gain in creativity was not significant.
The authors call for future studies to account for family background and for how fully each school applies the method.

Cognitive Benefits

Denervaud et al. (2019)

Beyond Executive Functions, Creativity Skills Benefit Academic Outcomes, PLOS ONE 14(11), e0225319. A cross-sectional study of 201 children in Switzerland, half from Montessori schools and half from traditional schools.

Montessori students scored higher on academic measures and on creativity in both age groups studied.
There were no differences in overall executive function, except working memory.
The Montessori schools were private and the comparison schools public, so self-selection can’t be ruled out.

Lane-Barmapov (2016), Master’s Thesis

Montessori and Autism: An Interpretive Description Study, Master of Health Studies thesis, Athabasca University (the university’s online copy is currently unavailable).

Watch Out. This is a graduate thesis, not a peer-reviewed article.

It asked how Montessori teachers adapt the method for children diagnosed with autism, based on the teachers’ own accounts.
It describes teaching practices and does not measure children’s outcomes.

Mental Well-Being

Lillard et al. (2021)

An Association Between Montessori Education in Childhood and Adult Wellbeing, Frontiers in Psychology 12, 721943. A survey of 1,905 adults, about half of whom had attended Montessori schools.

Attending Montessori for at least two childhood years was associated with higher adult well-being on four measures (general well-being, engagement, social trust and self-confidence), after accounting for age, gender, race, childhood income and years in private school.
More years of Montessori went with higher adult well-being.
The authors note that unmeasured selection effects could explain the results.

Key Research Takeaways

Consistent Findings

Both 2023 meta-analyses found average academic effects favoring Montessori, though the effects were modest and varied from study to study.
Lottery and randomized studies in the US and France found reading advantages by the end of preschool or kindergarten (Lillard and Else-Quest 2006, Courtier et al. 2021, Lillard et al. 2025).
Results for executive function are mixed. They were positive in Randolph et al. and in the 2025 trial, but very slight or absent in Demangeon et al. and Courtier et al.
Implementation seems to matter. High-fidelity classrooms showed larger gains in Lillard (2012), and Randolph et al. found larger effects in private than in public programs.

Areas for Further Research

Long-term outcomes into adulthood, where the evidence so far is correlational
Middle and high school, where studies are fewer and effects were smaller
Results for different groups of children and in different countries
More randomized and lottery-based studies