Maria Montessori and the Montessori Method: Life, Materials and Timeline

Who was Maria Montessori: youth and studies

Maria Montessori was born in Chiaravalle, in the province of Ancona, on 31 August 1870 and died in Noordwijk, in the Netherlands, on 6 May 1952. She was an educator, and her surname names a way of running a school that is used in many countries. According to the Dizionario Biografico degli Italiani she was an only child of Catholic, liberal parents with a patriotic outlook. Her father, Alessandro, was a civil servant at the Ministry of Finance; her mother, Renilde Stoppani, came from a family of small landowners in the Marche. After a stay in Florence the family settled in Rome in 1875, and Maria spent her childhood and youth there.

As a young woman she wanted to be an engineer. She attended the Michelangelo Buonarroti technical school from 1883 and the Leonardo da Vinci technical institute from 1886 to 1890, then enrolled in science. In 1892 she switched to medicine, with some difficulty, since very few Italian women took up those studies.

In 1894 she won a study prize from the Rolli Foundation, and in July 1896 she graduated with a thesis on hallucinations, drawn from research in the psychiatric clinic of the University of Rome. That same year she took part in Berlin in the first congress of the International Council of Women, devoted to women’s rights.

On the question of being first, the Treccani encyclopedia entry presents her as the first woman to graduate in medicine in Rome, in 1896. The Dizionario Biografico and a 2017 review from UCL write “one of the very first”, a more cautious wording.

By then she had taken an interest in the children whom the period called “deficient”, a term now out of use, and had studied the work of Jean Itard and Édouard Séguin. In 1897 and 1898 she stayed in Paris to read Séguin. In 1898 the minister of education, Guido Baccelli, gave her a course in psychiatry for the teachers of Rome, and from it grew the city’s orthophrenic teacher-training school. In 1900 she took over its direction together with her colleague Giuseppe Montesano. From 1904 to 1910 she was a lecturer in anthropology in the faculty of science.

Maria Montessori’s private life and her son Mario

On 31 March 1898 Maria gave birth in secret to a son, Mario, from her relationship with Giuseppe Montesano. To avoid a scandal that would have damaged both their careers, the two kept the relationship and the child hidden. As a boy Mario saw Maria when she came to visit him, but he did not know who his parents really were. In 1901, after increasingly serious disagreements, the break with Montesano was final.

In 1913 Maria took Mario to live with her. In public she did not say he was her son: she introduced him as an adopted son or a nephew. In 1915 she went back to America with him, and he settled there.

Mario (1898-1982) had a role of his own. According to the Dizionario Biografico, the Association Montessori Internationale, the AMI, was founded in 1929 partly thanks to his firm commitment. In January 1933 mother and son withdrew together from the Opera nazionale Montessori, in 1934 they left Italy, and in 1947 Mario married Ada Pierson, who had invited them to settle in the Netherlands.

The first Children’s House and the 1909 book

In 1906 the engineer Edoardo Talamo, president of the Istituto romano dei beni stabili, asked her to set up a nursery on modern lines for the children of the workers who lived in the new public housing blocks, particularly in San Lorenzo. The first Children’s House (Casa dei Bambini) opened on 6 January 1907 in San Lorenzo, Rome, under Montessori’s direction and in the care of Candida Nuccitelli. The method had been devised for children with cognitive disabilities and was then extended to the others.

In 1909 the Franchetti barons persuaded her to write her major work and paid for its publication with the Lapi firm of Città di Castello. The title is Il metodo della pedagogia scientifica applicata all’educazione infantile. The path starts from sensory education with structured material and moves gradually to intellectual education. The starting point is a quarrel: Montessori rejected the teacher who imposes facts on pupils with rewards and punishments.

In 1910 the method moved from preschool to primary school, at the elementary school of La Montesca, in Umbria. In January 1913, in Rome, Montessori gave the first international course on her method, which is regarded as the start of the Montessori movement. Students from the United States and 17 other nationalities took part.

How the Montessori method of teaching works

According to a 2017 review from the UCL Institute of Education, the heart of the method is a dynamic triad of child, teacher and environment. The prepared environment is the classroom space organised so that the child can explore and choose alone, in support of the child’s development. In Montessori’s view a child goes through sensitive periods for learning and through several stages of development (the stages of another theory, Piaget’s, have a Recap of their own: Piaget’s stages of cognitive development). She thought a child can build himself or herself up through activities the child directs. A neighbouring idea, in which learning is active, is discussed in the Recap on constructivism.

In Montessori’s view the teacher guides the work children do on their own initiative and follows each one closely. The Treccani encyclopedia describes the teacher as someone who assists each child practising alone with the material. In the practice described by the 2025 PNAS study, the teacher gives individual and small-group lessons, but learning comes mainly from the freely chosen use of a curated set of materials that children touch and handle.

Then there is the material. Every piece has a control of error, meaning the material itself brings a mistake to light and the child fixes it with little input from the teacher.

Practical example: in the 1912 edition of her book, Montessori describes the rods of decreasing length. The child lays them out in a scale. If one is out of place, the scale loses its regularity and you can see it at a glance, with nobody saying a word.

Montessori also noticed that small children can stay absorbed for a long time in what interests them on their own. The work periods are long. Classes bring together children of different ages, so the older ones act as models and help the younger.

The 2023 review describes the structural elements of AMI-recognised Montessori.

Element	What it looks like
Ages in a class	A three-year band, for example 3-6 or 6-9
Work time	An uninterrupted block of 2.5-3 hours in which children choose freely
Adults	Large classes with few adults
Materials	The full, self-correcting set
Grades	None

The 2017 review adds that the ideal is a single class for ages 3-6 and a three-hour work cycle. In one study the cycle was cut to 30 minutes.

From Italy to the world: fascism and exile

The method was taken up in schools in many countries, including outside Europe, such as the United States, Canada, India and Japan. The English translation of the book came out in 1912 and was an extraordinary success in the United States. The decline of its American success was also due to criticism from the progressive education movement, from John Dewey and above all William Heard Kilpatrick, who spoke of an “individualist” approach.

In Italy her relationship with those in power changed several times.

Year	What happens
1924	The Opera nazionale Montessori is founded as a legal body, with offices in Rome and Naples: Giovanni Gentile as president, Maria Montessori as honorary president
1929	The AMI is founded
1931	The first international congress of Montessori studies is held in Rome
1933	Maria and Mario withdraw from the Opera
1934	After a protest that interrupts the Montessori congress, they leave Italy for Spain
1936	The Spanish civil war takes them to England; minister De Vecchi shuts down Rome’s Regia Scuola di Metodo
1939	Maria goes to India with Mario for a course for Indian teachers
1946-1947	She returns to the Netherlands, then goes to Italy to reorganise the Opera and reopen the schools

In 1924 the Opera had the backing of the fascist regime (for the regime and its propaganda, see the Recap on the Mussolini myth). In the 1930s Montessori schools were closed by the regime, and the same happened in Nazi Germany. The regime adopted the Agazzi method of the Agazzi sisters instead, which is a different pedagogy.

The outbreak of the Second World War kept Maria in India. Mario was held for a short time because the British authorities regarded him as an “enemy”. In India Maria made observations on the development of infants and on the child’s mind, and in 1949, in Adyar, she published The Absorbent Mind. In 1947 she went back to Italy without moving there: her main home stayed in Amsterdam. She was nominated for the Nobel Peace Prize and died on 6 May 1952 in Noordwijk aan Zee, where she was buried in the Catholic cemetery. Her personal archive is kept in Amsterdam, at the AMI.

What research says about the Montessori method

In 2017 a review from the UCL Institute of Education wrote that the method had existed for more than a hundred years but evaluations of its effectiveness were scarce. Methodologically sound ones were very few. The review called the one by Lillard and Else-Quest arguably the strongest, published in Science in 2006, which compared children aged 5 and 12 in a Montessori school and in other kinds of school, all of whom had entered the admissions lottery. It was criticised because it rested on a single school. The same review notes that adopting wholesale, and uncritically, a method born over a hundred years ago in a different world could be risky.

The 2023 systematic review searched for studies up to February 2020. Of the 2,012 articles found, 173 were examined in detail and 32 met the criteria. They produced 204 effects, 113 academic and 91 nonacademic. The effect is measured with g, where positive values favour Montessori. The overall effect is g = 0.24 on academic outcomes and g = 0.33 on nonacademic ones.

Area	Effect (g)	Quality of evidence
Language	0.17	High
Mathematics	0.22	High
Executive function	0.36	Moderate
Creativity	0.26	Moderate
Social skills	0.23	Low

Effects are larger in randomized studies than in non-randomized ones, in early childhood and primary school than in middle and high school, and in private Montessori than in public. The comparison with small studies favouring traditional schooling hints at possible publication bias, but the sensitivity analysis indicates that the results stay robust. Angeline Lillard is also an author of this review, of the PNAS study and of the 2006 one: part of the research comes from a scholar of the method.

The study published in PNAS in October 2025 is a national randomized trial of public Montessori; the four earlier ones were limited to one or two schools. It included 588 children who had entered the admissions lotteries of 24 public schools in the United States, tested in autumn 2021, at age 3, and again each spring until the end of kindergarten in 2024. About half of the children who had been offered a place were still in a Montessori school in kindergarten. At the end of ages 3 and 4 there were no notable effects. At the end of kindergarten, at age 5-6, with starting scores and demographics held equal, the Montessori children had significantly higher scores in reading, short-term memory, theory of mind and executive function. The authors write that the effect sizes exceed one fifth of a standard deviation, which is considered large in field research on schooling.

The authors also state the limits. The 24 schools were not chosen at random and had more applicants than places for 3-year-olds. The results may not hold for families who do not apply to a Montessori school or to lotteries. COVID-19 may limit how long the findings stay valid. Among families offered a place, at the start of the study in 2021, 68% reported an income above $75,000, against 56% of the others, a difference controlled for in the analyses. In kindergarten end-of-year testing, 32% of the children with a Montessori place and 42% of those without could not be assessed.

In December 2025 a French study traced 97 children five years later, now in traditional classes, with an average age of 10-11, in a socio-economically disadvantaged neighbourhood in the Lyon area. In reading they were no further ahead than their classmates (d = -0.07). In mathematical problem solving they were (d = 0.58), an advantage that was not there in preschool. The curriculum was an adaptation: fewer materials, shorter work periods, relatively little teacher training. On executive function and social skills the authors found no measurable advantage at any point.

The Montessori name and criticism of the method

According to the 2025 PNAS study, Montessori is the longest-lived alternative pedagogy, dating from 1907, and the most widespread. The name, however, is not a registered trademark.

Practical example: a school presents itself as Montessori. The elements described by the 2023 review give a yardstick for looking at it: classes with a three-year age band, an uninterrupted work period of 2.5-3 hours, the full set of materials, no grades.

The historical criticism reported by Treccani concerns rigidity: according to critics the child receives an imposed material, and teachers and children must follow procedures fixed in advance, at the expense of the spontaneity and freedom the method started from.