This thesis is about stereotype and preconception characteristics, what causes them and what consequences they have. There are three social psychology approaches to what causes prejudices. It is known that stereotypes are developed in early childhood when children start to learn about gender roles. Therefore, theories about causes of gender role development in childhood will be mentioned. In stereotype development, it is important to mention teachers influence and learning materials which conceal gender stereotype. In this thesis, there will be a list of actions and activities that teacher can use in class in order to reduce developed preconception and stereotypes in children. The purpose of the research conducted among students of second, third and fourth grade is to find relation between gender stereotypes, classroom atmosphere and some characteristics such as gender, age and school success. It was discovered that there is no correlation between gender stereotyping and classroom atmosphere or school success. However, it was found out that there is a connection between gender stereotyping, age and gender. It is evident that younger boy students are more inclined to stereotyping.