When a child shows a particular interest in one area of learning and development, for example, movement (crawling/ walking), language, stacking, lining up things in order, reading, etc it is called a SENSITIVE PERIOD. 

A sensitive period describes a moment/ a period when the child is particularly attuned to learning a certain skill or concept and it happens effortlessly. Think developmentally staged and ready to learn the skill in a flow state.

“A sensitive period refers to a special sensibility which a creature acquires in its infantile state, while it is still in a process of evolution.”- DR. Maria Montessori

As per DR. Maria Montessori, we can observe the children notice what sensitive periods they are in and provide appropriate activities to encourage those interests.

Below are some typical sensitive periods for babies and toddlers.

Sensorial: Babies learn through their senses and are fascinated by color, taste, smell, and things they can touch, or are soothed when they hear gentle sounds.

Movement: Babies and toddlers acquire gross and fine motor movements when they learn to walk and use their hands and as they get older refine these skills and develop coordination. E.g.- a child playing with a ball continuously is in a sensitive period of movement.

Language: Babies move their lips and babble and feel awe at the sounds that come out their mouths and then suddenly there is a language explosion. The way a child imitates and learns language from 0-3 years is fascinating. As adults, we struggle to learn a foreign language with such perfection. Interest in writing may begin at 3.5 years and in reading after 4 years.

Tiny Detail: from 18 months to 3 years the child is attracted to small objects and minute details.

Order: Toddlers love order. Dr Montessori observed that if a child sees something out of their routine or order they get upset. Routine and order calm the child. That is why "Have a place for everything and everything in its place."

Manners and Courtesy: This sensitive period starts around 2 years, before this, the primary caretaker can be the role model for manners and courtesy for younger children to see how it's done through language and movements and will absorb them

How does a sensitive period occur?

During the time of a sensitive period, an instinctual appetite for knowledge appears in the emotional structure of a child, causing a sudden, insatiable interest in a particular subject or skill. When a sensitive period appears in your child, it will affect him or her to the point that he or she may begin to repeat related tasks over and over with a form of absorbed and timeless enthusiasm, until this feeling is eventually satisfied. It is the role of the adult, during a child's sensitive developmental stages, to stay out of the way as far as possible to avoid hindering your child's independent pledge to development.

Environmental integration

Your child will use everything that he or she can in the prepared environment to better understand the skill that he or she is suddenly sensitive to. It is from this sense of personal awakening and discovery within, that your child can develop internal personality traits and skills. This work can only occur in a well-prepared environment during a sensitive period.

How can adults identify a sensitive period in a child?

Sensitive periods, while being a trait that the adult should not hinder in any way, are certain traits that can be observed in developing children, during the time spent in a prepared environment.

Now a sensitive period itself has many traits that help us as parents and teachers, to easily identify and understand them. In this way we can say that the sensitive periods include the following traits or characteristics:

Universal

Every child born in this world undergoes sensitive periods.

Unconscious

Sensitive periods are often coupled together with unconscious behaviour that results from some confusion in your child during this natural stage of learning.

Transitory

Sensitive periods are psychic states of sensitivity that your developing child has access to for only a limited amount of time. During this limited time period, your child can experience an instinctual sense of awakened impulses towards a particular skill of development, to which they become extremely sensitive or drawn.

Occurring simultaneously

During the sensitive stages of a child’s development, it can often be found that another sensitive period is still beginning while another is ending or is running concurrently at the same time as another sensitive period entirely.

Observable

Due to the nature of a child’s attraction to a certain activity and repetition of it, it is easy to observe and identify.

Why is a child better off learning through his or her sensitive periods than just learning everything at random?

“There is, within it, a vital impulse, which leads it to perform stupendous acts. Failure to follow these impulses means that they become helpless and inept. Adults have no direct influence on these different states. But if a child has not been able to act according to the directives of his sensitive period, the opportunity of a natural conquest is lost, and is lost for good." – Dr. Maria Montessori, The Secret of Childhood

Children who learn through the development of their sensitive periods can truly discover and reach their full developmental potential. Children can explore related skills naturally during their sensitive periods and will never tire during the time that they spend engaging with a related activity and work materials.

It is because of the psychic powers that are present during the time of the sensitive period. It is these innate psychic powers that allow a child to experience a sense of focused engagement for extended periods of time without losing interest, concentration, or energy.

Maria Montessori's discovery of the power of a sensitive period:

Maria Montessori first discovered the phenomena of the power of a sensitive period while observing one of her students at the Casa del Bambini school in Rome:

In the first Montessori school that Maria Montessori ever opened, after her work with retarded children at an asylum in Rome, Montessori discovered something amazing about a little girl she observed. The girl was completely rapt in a single activity to do with cylinder blocks. Dr. Maria Montessori had other children dance around her and even moved her, but this little girl just kept on working on the cylinders, as though she were in another world.

After the child had practiced the cylinders 42 times, the girl felt completely rested and alert. It was through this discovery that Maria Montessori discovered that a child’s inbuilt processes of sensitive learning include a lot of interest-based repetition, in accordance with a sensitive period that they may be experiencing, taking on so much psychic power that the rest of the world may completely dull out into a blur around them.

The sensitive periods of development are also the natural key periods of time that can map out a greater purpose and destiny for a child through the full exploration of innate tendencies within. Your child may explore these tendencies both through work, play, and exploration in his or her environment, during these sensitive periods.

The sensitive periods are a time of great transformation, in which the child has the power to advance his or her skills more profoundly and to evolve developmentally as a person in ways that would otherwise be far harder and take far more time to achieve.

Conclusion

It is in these ways that it becomes easier to understand why the sensitive periods are so important to respect, admire and encourage during your child's development. For it is as we understand, as parents or teachers, that through honoring our children's sensitive needs and nurturing their developing skills, we also allow them a chance to develop far greater potential than would otherwise have been possible.