The cognition and acquisition of gender behavior is also a part of children's cognition of gender role. In short, children need to gradually know the social expectation of male role and female role in observation and imitation. For example, the society generally expects boys to be brave and strong, girls to be gentle and clever, but in the kindergartens where there is a lack of males, boys cannot be gay The concept of man's role in society is totally empty because of the study of man's behavior. At the same time, it also leads to children's failure to complete the cognition of gender role in this stage.