The
sensitive periods are times in a child or person's life when we are able to learn a new skill without effort; or, without maximum, extended effort. An example is when the infant learns to speak their native language. Although the child practices the skill and rehearses new skills, on the whole the child learns the new language easier than an adult trying to learn a new foreign language. Make sense? The child is in the sensitive period to learn their first language. The child learns the language "easily."
Maria Montessori defined sensitive periods for a variety of human skills. I will list them on my next edit of this entry.
If we "miss" learning something during a sensitive period, then we have to struggle very hard to acquire that skill, and we never quite achieve the mastery of the skill that would have been obtained during that period.
All Wikipedia text
is available under the
terms of the GNU Free Documentation License