Gender-specific expectancy effects in mathematics. What rote does the professional knowledge of teachers play?

Teacher expectations are considered an important factor in students' achievement development. However, it is still unclear to what extent teacher characteristics influence their expectations. One important teacher characteristic is their professional knowledge. Based on a sample of 796 primary school students and their 50 teachers, this study examined the relations between students' gender, teacher expectations of student mathematics achievement, professional knowledge of teachers and student mathematics achievement. The focus was whether the professional knowledge of teachers is related to gender-specific teacher expectation effects. Multilevel analyses showed a positive relation between teacher expectations and student mathematics achievement. In addition, teachers had higher expectations for boys' mathematics achievement than for girls' mathematics achievement. Furthermore, teachers' higher expectations of boys' mathematics achievement explained the differences between boys' and girls' mathematics achievement. We could not find any relation between the professional knowledge and the gender-specific expectation effects. Possible approaches to minimize expectation effects are discussed.