Montessori was deeply concerned with the nature of development in adolescence, and the disparity between the expectations of formal school settings and the needs of learners at this age. In this Third Plane of Development, from 12-18 years old, learners are moving through rapid changes in their physical bodies and equally chaotic changes in their sense of belonging and of identity.
"If puberty is on the physical side a transition from an infantile to an adult state, there is also, on the psychological side, a transition from the child who has to live in a family, to the man who has to live in society . These two needs of the adolescent: for protection during the time of the difficult physical transition, and for an understanding of the society which he is about to enter to play his part as a man.
- Maria Montessori, From Childhood to Adolescence, p. 60)
It's these critical transitions that define the preparation of the adolescent environments in Montessori, a preparation that takes special care to protect the Freedom for Movement. Indeed, Montessori's model for 12-15 year old classrooms, the Erdkinder, suggests that children at this age should not be in school at all, but rather working in engaged physical activity. This model prioritizes the child's physical development as a means to provide satisfaction and balance to the internal chaos of this time.
While traditional classrooms may frame these years as the time to "buckle down," Montessori classrooms open them up to provide more movement and physical engagement than at any previous stage of development. Learners in 12-15 year old environments may be working gardens or helping to raise and care for farm animals. They may be deeply involved in construction projects, learning to create their own physical spaces, working the land and working with their hands. Montessori teachers, then, find the windows of opportunity within these large-scale physical projects to integrate academic content. Students may read texts about the environment while they are caring for their school farm. They may be challenged to apply their understanding of geometry as they construct buildings. They'll learn science and social studies through hands-and-bodies-on projects.
And then, typically at age 15 or so, Montessori environments will invite learners back to rest, as they are ready to learn abstractly and through deep conversations. Classrooms will look more like seminar spaces, with students still pursuing the work that is of most interest to them but doing so with a focus on their intellectual development. It is because the previous years have allowed for the open-ended exploration of the world through their bodies that learners develop the capacity to regulate them. Protecting the Freedom for Movement throughout children's development gives them the time to master their own bodies on their own schedule and, ultimately, to integrate that mastery as thinkers with agency, discipline and contentment.