“Sensitive periods are blocks of time in a child’s life when he is absorbed with one characteristic of the environment exclusive of others. This particular sensitivity towards certain stimuli lasts until a necessary need is fulfilled.
The sensitive periods are transitory periods in the child's life during which she is prompted by an inner urge to focus her attention on certain elements in her environment. The activities and impressions resulting from this activity help the child to form a faculty with which to fulfill a tendency.
After a spell of work done at the imperious bidding of this inner urge, the child, or individual, feels better, stronger and calmer--simply because he has been creating herself. A sensitive period has a beginning, a high point, and a fading out phase. It has a period of building and a period of perfecting....
Maria Montessori identified 6 sensitive periods
1. Sensitivity to the order: At this time the child has a passionate interest in the order of things in time and space. Everything has to be in its proper place and the actions of the day have to be carried out in an accustomed routine. A child is upset by not getting his usual spoon, or cupboard door is left open, or the corner of a rug turned over; or a story being retold with different words or turns of events. Small children can be driven frantic by such infringements [changes in] established order, and they often protest with temper tantrums. He needs the stability and the security that order gives.
The order in the child’s environment is his foundation he absolutely needs it for orientation. First, for physical orientation to find his way around, and later in mental orientation and for classification, this sensitive period establishes within him the rhythm he needs in order to fulfill his tendency for order.
When the sensitivity to order is lacking, the child may not be able to orientate himself and...