Dutch biologist Hugo De Vries was the first person to speak about and define the sensitive periods during his research with animals. These observations in nature were part of Montessori’s studies as well. She observed similar situations in ‘normal young humans’. This appeared to be the same globally, with all children no matter where they were born geographically, or what culture they belonged to.
Sensitive periods are transitory periods of time in a child’s life when he is especially sensitive to certain aspects of the environment. They appear through patterns of repeated behaviour. The Sensitive Periods are not linear, i.e., they do not follow one after the other; some overlap and some are continuous. Montessori education was developed with attention to the Sensitive Periods as a central theme. If a child is prohibited these sensitive periods, the natural consequences are shown with the disturbing effect on psychic development and maturity. As soon as a sensitive period appears the child must be assisted. It is important that we as adults have knowledge of the sensitive periods and use this information in our environment to avoid barriers for the natural development of all children.
Knowledge and understanding of the world are built through our senses, which is a slow process that goes on throughout childhood. “The education of early childhood should be based entirely upon this principle: Assist the natural development of the child.” (Discovery of the child, chapter 9, pg. 144)
There are two necessary conditions that need to be met in aiding and assisting the child during his sensitive periods. Child is dependent on integral relationship with his environment – both things and people. Only through this interaction can the child come to an understanding of his self and the limits of his universe. Child requires freedom: If the child is given the key to his own personality, and is governed by his own laws of development, the child is in possession of the very sensitive and unique powers which can only come forth through freedom.
If either of these two conditions are not met, the child will not reach full potential of development and his personality will be stunted.
A period for sensitivity to order
One to two years: In this period the child will show his need for order in different ways. He has an ardent desire for consistency and repetition. What we have come to know as the terrible twos is actually associated with a child’s routine being disrupted. The child can react very badly to small disruptions that an adult has not really taken notice of. For instance the child whose puzzle is in a certain place on a shelf. While cleaning mum has forgotten to put it back, this can cause the child to have a tantrum, as his sense of order has been affected. Keeping order and routine aid the child during this sensitive period. If this need is not met, the child's ability to reason and learn will be beset with difficulties, since she may not be able to consider her conclusions reliably.
A period for the refinement of the senses
Birth - four years: A child takes in information about the world through his senses. In order for the child’s mind to develop, he must have access to a variety of aids and objects within his environment. A newborn baby starts life with no more ideas in its head than a newborn puppy. And yet, within the short period of three or four years, children who have been normalised will have notions such as softness, hardness, height, length, goodness, badness and so forth. One of the aims of sensorial training should be to help the child attain maximum refinement of his senses. “Beauty is found in harmony, not in discord; and harmony implies affinities, but these require a...