Sensitive Period

A sensitive period is a window in development during which an organism is unusually receptive to particular kinds of experience or learning, so that exposure during that window has an outsized effect on later development, but the skills or traits associated with it can still be acquired, with more effort and less completely, outside the window. Language acquisition is a commonly cited example: young children usually acquire native-like pronunciation and grammar far more easily than older learners, yet adults can and do still learn new languages. The concept is closely related to, but distinguished from, a critical period, in which an ability is thought to become effectively impossible to acquire once the window has closed.