If you tell someone your child goes to a Montessori school, one of the first comments you may hear is, “Is that the school where different ages are all mixed together?” Indeed! This is one of the defining qualities of a Montessori education. However, “different ages all mixed together” misses much of the observational rigor and scientific reasoning that went into the original creation of the Montessori multi-age classroom.

When Dr. Maria Montessori first created her educational pedagogy, she spent years observing children in their natural state to come to scientific conclusions about their development. Primarily among these observations was the presence of defining characteristics that marked age ranges (or “Planes of Development”) where these children’s needs would be fulfilled in the same way. Once she understood these ranges, which were broader than a single age level, she further observed the ways that all the children within each age group were served by being in a class “all mixed together,” as it were.

Since then, Montessori schools have upheld this understanding of child development and continued to offer environments that serve children within a range of ages. These environments are suited specifically for each plane of development in every detail—their layout, materials, curriculum, lessons, manner of working, expectations, social opportunities, and interactions with the students. By acknowledging the general characteristics of age ranges, and offering environments that meet these characteristics, Montessori classrooms are able to serve children comprehensively throughout their development. They not only are able to meet the intellectual and developmental needs of children, but the multi-age environments also offer other opportunities and benefits for the students of all ages.

Planes of Development

Dr. Montessori saw that childhood could be divided into four main Planes of Development: birth –6 years, 6–12 years, 12–18 years, and 18–24 years. Furthermore, she observed that for the first (0–6) and third (12–18) plane, these groups can be divided into “sub-planes” (0–3 / 3–6 and 12–15 / 15–18). The sub-planes distinguish between two phases of a child’s development where there is a more significant transition than year to year growth, but not as substantial as the transition between planes.

Birth to Six Years (The First Plane of Development)

The first six years of a child’s life bring about the most extraordinary physical changes that a person will ever experience. The small, helpless newborn will become a walking, talking, and competent child in just six years. During this plane, a child has a concrete understanding of their surroundings. They seek order so they can make sense of their new world around them. They are vulnerable, sensitive, and require a great deal of love and security in order to give them stability. They are social in the sense that they are curious about the people around them, but they do not yet have the ability to internalize someone else’s point of view. The first three years (the first sub-plane) are marked by a tremendous physical leap—from complete helplessness to the ability to feed and dress themselves, as well as walk, climb, run, and communicate. During this time, their awareness is largely unconscious. The second three years (the second sub-plane) has fewer dramatic physical changes as children complete the transition from toddler to elementary child. It also marks a period of increasing conscious awareness of themselves and their ability to learn, as they participate in intentional engagement with their environment with self-direction.

Six to Twelve Years (The Second Plane of Development)

An Elementary child is generally active and sturdy. They are lankier than in their early childhood. These students have tremendous intellectual capabilities. They have well-developed imaginations and an accompanying ability to abstract. They are curious about the workings of the universe and how everything fits together. Elementary children are actively social. They are not only deeply curious about people around them, but they are able to begin to comprehend the inside workings of their minds. The social world is endlessly fascinating to them. They want to work with their peers, and they are able to do so productively and meaningfully. They have a passionate interest in morality, and they look for people to admire in the world outside of their home.

Twelve to Eighteen Years (The Third Plane of Development)

Dr. Montessori observed that the third plane parallels many of the qualities of the first plane. They are both marked by extraordinary physical growth, and they both are characterized by a transition from one life stage to another. The first: From infanthood to childhood. And the third: from childhood to adulthood. These major physical and metaphysical changes bring about many of the same characteristics that are seen in young children. Adolescents are vulnerable and sensitive, and they look for genuine encouragement and support from the adults around them to hearten their sense of self. While they have greater social abilities than babies and toddlers, their attention turns inwards again. They are introspective as they ask questions about who they are and how they fit into their broader society.

Classrooms and Environments for the Different Planes

Given the similar needs of children during their planes of development, Dr. Montessori designed environments that were able to meet the needs of children during specific ranges of ages. She wrote, “Successive levels of education must correspond to the successive personalities of the child. Our methods are oriented not to any pre-established principles but rather to the inherent characteristics of the different ages” (From Childhood to Adolescence, 1).

Home or a “Nido” (0–1.5 years old)

The smallest babies, who are not walking or talking, need an environment where their physical and emotional needs are met quickly. Here, they have a small world to explore with familiar adults whom they love and trust. They have just enough stimulation to be active and learn, but they have plenty of time for quiet, for naps, and for peaceful meals. At this age, babies have basically no conscious awareness of each other, and no true need to be social with other young children.

The Young Children’s Community (1.5–3 year olds)

The toddler is now walking and talking. They are in the process of separating their identity from their primary caregivers and benefit from having time and space in their own community to continue to understand themselves as autonomous beings. This special classroom is simple, uncluttered, and bright. It has chairs, tables, shelves, materials, and real tools that are perfectly sized for small children. The children work individually, as they are developing themselves from the inside, but they have opportunities to serve each other with their work—food preparation, caring for the classroom, and learning how to be respectful of other people’s individual needs and rights within a shared space.

The Primary Classroom (3–6 year olds)

At this age, children enter the classroom with conscious awareness of their peers and their surroundings. This environment offers more materials and a larger group of students. Shelves are grouped into Practical Life, Sensorial, Language, Math, Geography, and Music. Children are eager to learn the facts of their world, and these materials give them access to this information. They work primarily on their own at single tables, as their attention and abilities are still individually focused, with a few small group lessons as they turn six. Just as in the Young Children’s Community, they experience the customs and expectations of navigating a small community of individuals. Dr. Montessori wrote, “The class gets to be a group cemented by affection. Finally, the children come to know one another’s characters and to have reciprocal feelings for each other’s worth” (The Absorbent Mind, 333).

Lower and Upper Elementary (6–9 and 9–12 year olds)

While most Montessori schools divide the elementary group into two classrooms by age for practical reasons, students of this entire age range have very similar characteristics and needs. For this plane, children are eager to learn and work in groups as they sort out their social abilities and understanding. They want to learn about history, people across the globe, the inside of the earth, plants and animals from every continent, and anything else they can imagine from our universe. The materials and lessons in this environment reflect these interests and introduce the far reaches of the known world to the elementary child.

Secondary Level (12–15 year olds)

As children enter adolescence, they need the security of an intimate classroom setting to support and stabilize them, but also need access to extended and real experiences outside of the classroom where they can become valorized as they learn what they have to offer their society. Their classroom is a place where they once again return to more individual work, as when they were very young. This reflects the introspection of this age. They are deeply attached to their friends as they seek belonging, identity, and purpose through their peer group, and they benefit from occasions for collaboration within their small community. Their educational program offers opportunities to spend time living and working away from their family, often in the form of several 10-14 day trips over the course of their year performing service work, learning about history in other states, and relying on each other during adventures and exploration, such as canoeing and backpacking in the wilderness.

The Benefits of a Multi-Age Classroom

Within these classrooms, there are a host of benefits for children in their first, second, and third years in their environments.

A Natural Community of Peers

There are very few professional or personal groups of adults who are restricted by an age span of one year. Friendships are often made up of people who are at least one or two years apart, and many meaningful relationships are made up of people who are years, even generations, apart. In most work settings, there are colleagues of different ages, who learn from and are inspired by each other’s life experiences—the younger ones gleaning wisdom and perspective from elders, and the older ones gathering motivation and new viewpoints from the younger ones. These relationships make life richer and more interesting, intellectually and personally.

While college dorms are often divided by year, most courses are open to students of all ages. In high school, there are some classes restricted to year, but many have different ages. It is in preschool, elementary, and middle school that children are the most rigidly restricted to classes of only peers who are exactly their own age.

Dr. Montessori saw that this prohibitively restricted children’s social lives. She wrote:

"The charm of social life is in the number of different types [of people] that one meets… To segregate by age is one of the cruellest and most inhuman things one can do, and this is equally true for children. It breaks the bonds of social life, deprives it of nourishment" (The Absorbent Mind, 226).

A classroom that hosts a span of 2-3 years is alive! It is full of the natural encounters one expects to experience every day. A diversity of ages brings variety and meaning to the classroom.

Mentors

Children who enter the class as first-years have incredible mentors in their older counterparts—whether they are just one year ahead of them, as in the Young Children’s Community and Secondary Level, or one and two years ahead of them in the Primary and Elementary classrooms. From the first day that they walk through the doors, the class already has a rhythm and expectations that are set by the older students. Younger children are welcomed into a space that feels secure.

In fact, studies have shown that children in multi-age classrooms show increased abilities in motor, cognitive, communication, as well as overall development, in comparison with peers who attend single age classrooms (Lillard, 2005). Students benefit from having classmates just older than they are in many ways.

When they inevitably need assistance or guidance, they have more than just one teacher and one assistant teacher to turn to. They have an entire year of children who can already zip up coats, tie shoes, show them where the extra paper is, find an entry in the encyclopedia, explain the process for going into the prairie to observe butterflies, square an equation, or use the Algebra textbook. They have role models for behavior and social interactions. They have patient young teachers who will review their map pieces or equations with them. And, perhaps most remarkable of all, they will have two years of observing and overhearing future academic lessons—the capitals in Asia, sentence analysis, finding cube roots. So when their time comes, the concepts and language already have roots in their brain to take hold of, increasing the speed of fluency in many subjects.

True Leadership

Because of the span of ages, older children have two or three years where they experience being leaders within their environment. They gather confidence as they see how their contributions matter to the new students—the way they help them take care of themselves and the classroom, the way they introduce them to the procedures of the room, and the lessons they are able to teach them with the materials when the teacher invites them to do so.

They have implicit and explicit memories of what it was like when they were younger, and they are able to pull from those in order to rise to leadership and serve their younger peers productively. They get feedback when their efforts are not helpful, so they learn how to help in ways that can be received constructively. Dr. Montessori observed that this experience shows them how to lead with sensitivity: “They do not help one another as we do. If a child is carrying something heavy, none of the others run to his aid. They respect one another’s efforts and give help only when it is necessary.”

Finally, when they do give lessons on vocabulary, equations, geography, or other academic processes, they have an inherent review of the material. Instead of leaving the information behind, or feeling forced to review in a rote way, they are able to go over the work again, further cementing it in their minds.

Flexibility in Progress

While development and progress fall along a general track, children themselves do not progress at the same pace. Some may leap ahead what is considered typical, some may lag behind. And all will move along in jumps and starts—achieving understanding, and then holding steady for a bit before moving forward. Likewise, no child moves ahead at the exact same pace across subjects. They will take turns across academic areas, sometimes reaching further understanding in mathematics, sometimes in language, and so on. Learning does not occur in a straight line, nor in a single one!

There is tremendous benefit to having a class of many ages, because, at any given time, there is a high probability that there will be someone else who is near the same point of achievement and progress as someone else. They do not need to be in the same year, and often they are not. It allows a child who is accelerating through cubing lessons to connect with an older peer who is also doing the same work, instead of feeling overly inflated by being at the “top of the class.” It also allows a child who may be struggling with sentence analysis to have a review lesson with a young peer, and take the role of a social leader as they work together to more deeply understand the concepts—instead of feeling like they are falling behind a class who is moving in lock step.

In fact, research has shown that this academic experience enhances children’s cognitive skills, with a study indicating that children who spend three years in the same environment score higher on reading exams than children who enter the environment in that third year. There is an inherent academic benefit to the experience of a multi-age classroom (Carter, 2005).

This range of ages allows for greater grace with the range of ability that always naturally occurs with any group of people. Instead of having one year to master a curriculum intended for one year in a classroom, children are able to connect with classmates as they all work towards the same goal of mastering the curriculum at the end of their 2–3 years in the same classroom.

A Balance of Familiar…

Children who spend 2–3 years in the same classroom come to know the room, the materials, their peers, and their teachers deeply. It becomes an intimately familiar place for them, and they are able to delve thoroughly into their environment. They have time to thoroughly explore their lessons and work, as they are able to use the same materials to learn more complicated and advanced concepts.

In three-year classrooms, they spend two years with a group of friends one year older than they are, and two years with a group of friends one year younger. This provides the opportunity for prolonged experiences in leadership, having role models, and navigating dynamic social encounters. It prepares students for a variety of relationships and connections, and it strengthens their emotional and social awareness. Research has indicated that multi-age classrooms settings produce improved social skills in comparison with single-age classrooms (Saqlain, 2015).

Multi-age classrooms also provide the opportunity for children to spend 2–3 years with the same teacher. There is inherent value in allowing children to stay connected to the same adult for more than one year at a time. Teachers come to know their students deeply, which translates into even more effective teaching and classroom management. It also adds meaning to their relationships and gives students more confidence, as they develop security from the sense of stability this provides them.

…and New

A multi-age classroom is not all familiar. Even when students are returning to the same class, they are not returning as the same year they were before. A first year becomes a second year, and a second year becomes a third year. The first year children enter a classroom, and it is all new to them. They are the youngest and must learn how to find their way. This can be especially challenging for children who are the oldest at home! Our Upper Elementary teacher has shared that often the toughest year for students in her class is the year that is the most mismatched with their birth order at home.

After spending time as the youngest, in the three-year classes, the students spend a year in the middle, buffered on either end, and navigating roles as both younger and older than many of their classmates. And finally, they return as the oldest, and see the classroom through those eyes. This is often a year of great growth for children who are the youngest in their own families.

Every year, there is an outgoing of the oldest students, and an incoming of the youngest students. So while many of their peers remain the same, there is a turnover that takes place at the edges of the environment. New children enter a stable environment and bring their own personalities and interests.

These transitions freshen the experience as they make their way into greater leadership positions and find new ways of relating to their classroom and their new friends. Rather than feeling uninspired by something that might feel too familiar, they are able to be reinvigorated each year by a new role in their class.

Final Thoughts

The multi-age Montessori classroom arose because of Dr. Montessori’s profound observations about similarities across children’s ages. These observations offered new insight into development—and recognized that children’s needs and characteristics do not generally change drastically from year to year, and, instead, are made up of periods of rapid growth, followed by relative stability. Given these conclusions, she recognized that children within a 3–6 year age range did not need classrooms that were dramatically different from one another.

Furthermore, she also was able to observe and define the importance of not restricting children’s educational experiences to interactions with only other children of the same age. She saw that allowing a broader range of ages added a necessary richness to their days, and also offered invaluable opportunities for social and emotional development.

Some of the most important gifts schools and parents can offer children are well-developed social skills, confident and humble leadership abilities, graciousness when it is time to follow, and an ability to be flexible in a dynamic social setting. All these abilities combined make for productive and conscientious citizens in our greater world. The masterpiece of Dr. Montessori’s multi-age classroom is a fertile ground for all of these gifts to flourish, and, thus, allow children to step into the world, prepared for a beautiful and complex social life.

References

Carter, P. (2005). The modern multi-age classroom. Educational Leadership, 63(1), 54–58.

Montessori, M. (1995). The Absorbent Mind. Holt Paperbacks.

Montessori, M. (2020). From Childhood to Adolescence. Montessori-Pierson Publishing House.

Lillard, A. S. (2005). Montessori the science behind the genius. New York: NY. Oxford University.

Saqlain, N. (2015). A comprehensive look at multi‐age education. Journal of Educational and Social Research, 5(2), 285. https://doi.org/10.5901/jesr.2015.v5n2p285