Sensitive period

A phase in development when the organism is sensitive or has a greater susceptibility to particular forms of experience and learning that may be essential to later behaviour, and which is followed by a period of less sensitivity. It should be distinguished from ‚aacritical period‚aa that refers among other things to a period in life during which behaviour must develop. 

See Alcohol tolerance, Competence (embryology), Competence (psychology), Competitive exclusion model, Critical period, Developmental readiness, Filial imprinting, Imprinting, Induction (embryology), Teratogen, Thalidomide