这个问题很难分啊,因为就连人类学,社会学,医学(还有其它的学科)都各自有自己的分类.这个是非常有争议的东西.
Adolescent/YoungAdult(Age15-19),我的医学书上说是12-18岁.
infant,baby,toddlers是一样的
Ahumaninfant小过一个月可以被称为anewborninfantoraneonate."newborn"includesprematureinfantsandpostmatureinfants,aswellasfulltermnewborns.
以下是Erikson'sstagesofpsychosocialdevelopment
Infancy(Birth-12Months)
YoungerYears(1-3Years)
EarlyChildhood(3-5Years)
MiddleChildhood(6-10Years)
Adolescence(11-18Years)
EarlyAdulthood(18-34years)
MiddleAdulthood(35-60Years)
LaterAdulthood(60years-Death)