美国科学家本·斯·布卢姆提出,“在儿童的发展过程中,某种能力在某一特定时期最容易获得、最容易形成。如果错过这个时期,就不容易再出现这样好的时期。这个时期就是这种能力发展的关键期。”理论还认为,“2～3岁是幼儿学习口头语言的关键期;4～5岁是儿童学习书面语言的关键期;5岁以前是形状认识能力的关键期。” Ben Scully Bloom, a U.S. scientist, put forward: “In the development of a child, certain abilities are the easiest and harder to obtain in a given period, and such a good period is not easy to emerge again if we miss this period. This period is the critical period for the development of this ability. ”The theory also believes that“ 2 to 3 years of age is a critical period for children learning oral language; 4 to 5 years old is a critical period for children to learn written language; 5 years ago is the ability to shape understanding The key period. ”