Stages of Development Series: Maturity 18-24 years old
March 24, 2025

This is the final post of a series focusing on each of the four stages (or planes) of development: birth through age six, ages six to twelve, ages twelve to eighteen, and ages eighteen to twenty-four. Montessori pedagogy calls for a big picture perspective that incorporates the fundamental principles of human development at each stage of development and how we can best provide for a developing young person in each stage.


A Path Toward Maturity and Contribution to Society


The journey of human development, as envisioned by Dr. Maria Montessori, is marked by four distinct planes. Each plane represents a different phase in an individual's growth, and the fourth plane, spanning from 18 to 24 years of age, is no exception. This phase, which Montessori refers to as Maturity, signals the culmination of psychological and physical growth and paves the way for young adults to step into the world as a fully formed individuals capable of significant contributions to society.


Characteristics of the Fourth Plane


The fourth plane represents a time when individuals reach the height of their development and begin to assume their role in society. Unlike the earlier planes, the psychological changes during this period are less dramatic and more internal, and the focus shifts to understanding oneself and the world beyond one’s immediate needs. Whereas the body completes its physical maturation, the mind embarks on the task of understanding how it can contribute to humanity.


In The Four Planes of Education, Dr. Montessori writes, “The individual should be the man who knows how to make his own choice of action having passed to perfection the preceding phases. He should be as a live spark and aware of the open gate to the potentialities of prospective human life and of his own possibilities and responsibilities” (p. 15). This encapsulates the essence of the fourth plane— young adults’ newfound ability to make independent choices while being aware of their potential impact on society.


In this stage, individuals are not merely focused on themselves but are also learning to engage with the world beyond their personal ego. The question that arises is not “Who am I?” but “What can I do?” This shift from self-centeredness to a broader, more collective view of life signifies the maturity that defines the fourth plane.


Conquest of Independence


One of the key aspects of the fourth plane is the conquest of independence, particularly economic independence. This phase marks a time when individuals strive to become self-sufficient within the larger society. Young adults move beyond the dependency of childhood and adolescence, assuming more responsibility for their own life, finances, and future.


This is a period when a personal mission begins to take shape. Young adults start to solidify their goals, whether academic, professional, or personal, and work toward them with a growing sense of purpose. Dr. Montessori believed that achieving economic independence was crucial, as it not only provides the means to live but also fosters a sense of autonomy and responsibility.


Observable Examples of Development


Physically, by the fourth plane, development is largely complete. The dramatic growth spurts of the previous stages have slowed, and young adults now have full mastery over their body. Health is typically stable, and there is an overall sense of well-being.


Much like the second plane, the fourth plane is also conducive to intellectual pursuits, particularly those that lead to specialization in areas essential for a future career. This is when our young adults are honing skills that will serve them in the professional world, whether through higher education, apprenticeships, or other forms of specialized learning.


The fourth plane is also a time when individuals, having developed a solid understanding of themselves, are ready to take on more significant intellectual and social responsibilities. This is when they truly start asking the big questions, such as, “How can I contribute to the world?” It is at this stage that young adults embark on the exploration of their "cosmic task," a concept Montessori introduced in the second plane, which refers to the idea that every individual has a unique role to play in the larger story of humanity.


The Role of the Supportive Environment


With significant internal growth happening during the fourth plane, the role of the external environment remains crucial. A supportive environment during the preceding planes can have a profound effect on how individuals move through this stage. If our young adults have been nurtured in an environment that promotes autonomy, responsibility, and respect for their capacity to make choices, they are more likely to enter adulthood with the skills and mindset necessary to thrive in society.

To prepare for their careers during this time, many young adults pursue higher education, either through university studies or vocational training. Alternatively, they may enter the workforce, beginning to take on professional roles that contribute to society. This is also a time when many young adults leave the family home and start families of their own, further solidifying their place in the world as independent adults.


Dr. Montessori, unfortunately, did not have the opportunity to explore this phase in depth. However, we can imagine a world where every individual has been given the best possible environment throughout the previous planes of development. In such a world, adults who emerge from the fourth plane are equipped not only with the knowledge and skills to succeed but also with a profound sense of responsibility toward the greater good.


An Enlightened Society


The ideal outcome of the fourth plane is individuals who not only seek personal success but also work toward the welfare of humankind. Young adults who have passed through the earlier planes of development with the support of nurturing environments can enter society with a strong social conscience, eager to contribute to the collective well-being of humanity. They see the interconnectedness of all people and seek ways to address societal issues and contribute to the common good.


Imagine a world in which all young adults, having been guided through the previous developmental stages, emerge from the fourth plane ready to play their roles in society—not only as self-sufficient individuals but as enlightened members of a larger human community. This vision encapsulates the Montessori ideal: a world where everyone has the potential to contribute meaningfully to the advancement of humanity as a whole.


The fourth plane of development is not merely a time for self-discovery but a time for self-realization and societal contribution. Young adults, secure in their independence, prepare to engage with the world in ways that transcend personal goals, focusing instead on broader responsibilities. By fostering an environment that nurtures growth and independence, we set the stage for a society composed of individuals capable of making meaningful contributions to humanity’s collective well-being.


Curious to see how attention to the characteristics and needs of earlier stages of development can support an enlightened society? Schedule a tour today! 



October 27, 2025
Since the pandemic, we can find ourselves carrying new or heightened worries about our children’s social lives. We can have concerns about whether our children “lost time” with peers during critical developmental years. Or maybe it’s worry about shyness, reluctance in groups, or how screen time may have replaced face-to-face play. Even now, long after schools and activities have reopened, it’s common for anxiety to surface: Is my child making enough friends? Are they socially behind? Why We Feel This Way The truth is, these concerns are natural. COVID disrupted our social connections, and children being with other children is an important part of childhood. For months (and for some even years), daily opportunities to share space, work through conflict, and experience the joy of play were limited. Add in the reality of increased screen use, the culture of comparison amplified by social media, and children who may show hesitations around groups, and it’s easy to see why we are carrying this extra layer of worry. What Montessori Reminds Us Montessori provides us with a helpful perspective: growth is not lost, it is simply unfolding in its own time. Children are incredibly resilient. Social development isn’t a race, and there isn’t one perfect timeline. Just as each child learns to walk or read at their own pace, children find their own paths into friendships and community life. How We Can Support Children (and Ourselves) So, what can we do to ease our own (and our children’s) anxiety while supporting their social growth? First, remember that depth of connection matters more than numbers. A child with one or two genuine friendships has a strong foundation. In Montessori classrooms, we often see that meaningful, sustained interactions carry more value than a large peer group. Second, provide opportunities for natural interaction rather than overscheduling. Time at the park, family gatherings, or small playdates often offer more authentic growth than tightly managed activities. In the classroom, children practice collaboration daily, from sharing materials to working on group projects. Third, support independence. After COVID, it’s natural to want to step in quickly if our child seems uncomfortable socially. But small moments of trust—like letting our children introduce themselves, ask to join a game, or resolve a conflict—help them build confidence and resilience. Finally, model calm and social grace. Children absorb how we approach social situations. When they see adults showing openness and curiosity, they are more likely to approach peers with the same ease. Partnering with Teachers Your child’s teacher is also a valuable partner. Montessori guides closely observe children’s social interactions and can offer concrete reassurance: “I noticed your child inviting a friend to join her work,” or “He showed patience while sharing materials today.” These insights often show growth that may not be as apparent outside the classroom. Supporting Social Growth at Home Simple, practical activities in our children’s lives can make a big difference. Hosting a “work together” playdate, for instance, shifts the focus from entertainment to shared purpose. Children might bake bread, build with blocks, or create art together. These collaborative activities naturally encourage conversation, cooperation, and problem-solving, giving children structured opportunities to navigate relationships. Practicing grace and courtesy at home also builds confidence. Small role-plays, like how to join a game or politely declining an invitation, help children learn the social scripts they need. Learning how to insert themselves into play: “What are you playing? I’ll join too!” or “No, thank you. I’d like to work alone right now,” are examples that may seem small but make a significant difference when children encounter peers in real settings. Family game nights are another excellent tool. Cooperative board games, memory games, or card games teach turn-taking, handling winning and losing, and joyful connection. Games provide low-stakes opportunities to practice critical social skills like patience, negotiation, and flexibility. Finally, spending time in community spaces offers invaluable real-world practice. Visits to the library, farmers’ market, or nature center allow children to engage in everyday interactions, such as greeting a librarian, asking a vendor a question, or navigating shared space with peers. These experiences help children build confidence and fluency in social settings. Moving Forward with Confidence It’s understandable to feel anxious about our child’s social life after such a collective disruption. But rest assured: children are not permanently “behind.” With trust, time, and supportive environments, children continue developing the skills of friendship, collaboration, and community. Montessori reminds us that growth is steady and ongoing. Our role is to provide the space, opportunity, and confidence children need to thrive socially. When we step back and trust the process, we discover that children are, in fact, developing social competence. Come schedule a tour of our classroom environments in Oak Park, IL to see how Montessori fosters a lasting sense of confidence and a deep form of belonging.
Human Tendencies: Why Montessori Still Feels So Relevant
October 6, 2025
From curiosity to self-control, Montessori aligns with the human tendencies that help children grow, adapt, and flourish.