Sensitive periods

Sensitive periods is a term coined by the Dutch geneticist Hugo de Vries and adopted by the Italian educator Maria Montessori to refer to important periods of childhood development.
Montessori believed that every human being goes through a series of leaps in learning during the pre-school years. Drawing on the work of de Vries, she attributed these behaviors to the development of specific areas of the human brain, which she called nebulae. She felt this was especially true during the first few years of life, from birth (or before) to the time of essentially complete development of the brain, about age 6 or 7. Montessori observed several overlapping periods during which the child is particularly sensitive to certain types of stimuli or interactions. She describes these as "sensitive periods", a phrase coined by de Vries during his studies on animals.
According to Montessori, during a sensitive period it is very easy for children to acquire certain abilities...