Montessori believed that development was guided by inner motivation and that there are patterns of growth and development common to all people, universal forces that define and refine in us what it is to be human. Human beings do not have instincts in the way that animals do. Instead of instincts people have human tendencies which help insure survival, but also bring satisfaction. In Montessori's view human tendencies, along with intelligence and the ability to love, have given humans an almost infinite array of possibilities in how to live our lives, adapt to many different environments and still find fulfillment. She explained human tendencies as being part of the system of natural guides essential to survival and self-fulfillment.
As humans we all have a propensity to act in particular ways. Montessori believed that if we cooperate with these propensities, the tendencies will generate opportunities for our positive self-construction. These tendencies are universal to all humankind. They are unchanging and they assist us in our task to survive. Some of these tendencies are: a need and desire for order; a drive to orient ourselves to objects and people in an environment; a need to explore; a need to communicate; a need for activity; a need to manipulate objects with our hands; a need for work (defined as using our intelligence to fulfill a goal), repetition and practice; desire for exactness; abstraction (ability to visualize and create in our minds); self-perfection or the desire to improve oneself. Deeply considering the young child, Montessori designed an environment in which all of these natural tendencies would be allowed to operate from within the child to help him or her in the work of creating him/herself.
Montessori observed that a child passes through distinct developmental stages about every six years and that these stages can be divided into sub-phases. She thought that the different characteristics of children within these stages was so marked that all education should be formed around them. She also observed that children physically grow in "spurts." Growth can sometimes seem to speed up or stagnate. "The child does not grow in a uniform way day by day, at the same rate. In growth there are crises, somewhat like the metamorphosis of the insects." (The Four Planes of Education. A.M.I. 1971. pg.3) Through extensive observation of children from many countries and cultures, Montessori discovered that there are different characteristics, behaviors and sensitivities that occur at different stages of life and that these reflect the changing needs of the individual at each successive stage. Further, she observed that each stage of development was constructed on the previous ones and that if any thing was missed it needed to be made up in the next stage or the development of the personality was compromised.
The first plane is from birth to six years, the second from six to twelve years, the third from twelve to eighteen and the fourth from eighteen to twenty-four. The first plane is divided into two sub-planes birth to three and three to six. The greatest changes take place in the first three years of a plane. The next three years are for consolidation and strengthening of those changes. She also observed that the first six years and the years from twelve to eighteen had many similar characteristics.
A child forms his or her personality from birth to age six. Therefore, a child is self-centered by necessity. Some of the characteristics of children from birth to age six are: a passionate interest in everything they see; a vulnerability to illness because of the very great physical changes occurring in the body; a young child's development greatly depends on the people and experiences s/he interacts with in the environment. A young child needs to move in order to learn: thought and action are part of the same occurrence. A child learns by sensorial exploration, through his or her hands and senses, which are highly sensitive. The child's main developmental drive is to construct his/her personality. External order allows a child to get a clear understanding of the environment around her. Emotionally the child has a great need for love and security. Most children at age three prefer individual activity but increasingly enjoy it in the presence of others playing or working nearby. Young children are usually generous and trusting.
The absorbent mind is a term Montessori coined to describe the functional process within the child's mind from birth to six. During the first three years the child's mind functions unconsciously and during the next three years it functions consciously.
"The things he [she] sees are not just remembered; they form part of his soul. He incarnates in himself all in the world about him, that his eyes see and his ears hear. In us the same things produce no change, but the child is transformed by them. This vital kind of memory, which he [she] does not consciously remember, but absorbs images into the individual's very life, has been given a special name by Sir Percy Nunn, who calls it the "Mneme." (Montessoi, The Absorbent Mind, 1995, pg. 62)
Thus, the child does not screen information. The absorbent mind is like a camera. It takes no more effort to take a picture of a forest or of a single tree. The absorbent mind cannot evaluate the environment. A young child cannot determine what is right or wrong, good or bad without direction from an adult. Children are not logical or judgmental. They simply absorb everything. As they grow to age six, they gradually take on the language, culture, norms and values of their family and the world around them.
Montessori believed that in the natural gift of the absorbent mind lay the bright hope for the future of humankind.
"Mothers, fathers, politicians: all must combine in their respect and help for this delicate work of formation, which the little child carries on in the depth of a profound psycho-logical mystery, under the tutelage of an inner guide. This is the bright new hope for mankind. Not reconstruction, but help for the constructive work that the human soul is called upon to do, and to bring to fruition; a work of formation which brings out the immense potentialities with which children, the sons of men, are endowed." (ibid. pg. 17)
A sensitive period is a period of time when a child has a particular developmental need which ends when the need is met or the developmental stage passes. The child experiences an irresistible attraction or need for certain things and sensitivity to them. As a result of this sensitivity, a child gains a trait, characteristic or skill which lays the foundation for future development. These are periodic or transient instincts. Sensitive periods have five characteristics: they are universal to all children everywhere; they are observable; they result in the acquisition of a specific skill or trait; the period is transitory; and several sensitive periods occur simultaneously. Some of the sensitive periods evident in first plane children are: the development of language, refinement of the senses, order, movement, social behavior, to tiny things. A baby is driven to kick his legs over and over which eventually results in walking. S/he says sounds over and over which eventually results in speech. These are examples of sensitive periods.