Izbicki, Sarah. (2015). Acceptance and rejection of students by their teachers at different grade levels. Dissertação de Mestrado, Instituto de Psicologia, Universidade de São Paulo, São Paulo.Perceptions, expectations and preferences of teachers differ according to several variables (students' characteristics, school curriculum, schools' rules etc.) and are expressed by them through different attitudes taken before the students, so that they considerably influence those youngsters' behavioral repertoire. Given (a) the importance of a positive relationship between teacher and student in the course of student's school life, (b) the changes which occur in this relationship over the years, and (c) that even minor changes in the quality of this relationship have relevant implications for the student's development, it is necessary to investigate which factors are associated with those changes. The general aim of this research is to reveal the controlling variables of rejection and acceptance of students, as reported by their teachers, assessing potential differences between three different grade levels. Specifically, the study aimed to (1) compare the frequencies in which the students of each gender are indicated as accepted or rejected by their teachers at the three levels, (2) compare the reasons reported by the teachers to indicate the students as accepted or rejected at the three levels and (3) identify possible associations between the reasons for acceptance and rejection and the gender of the indicated students. 21 teachers of first grade of elementary school, 16 of sixth year of middle school and 28 of ninth grade of high school completed a questionnaire in which they indicated three students they would keep in their class and three students they would not, explaining the reasons for the indications. Inferential analyses did not show differences between the gender of the accepted students, and revealed small associations between the reasons for acceptance and rejection and the sex of the student. Nonetheless, there were differences between the genders of the rejected students, where a higher proportion of rejected boys was found. There were also differences between reasons for acceptance along the different educational levels, where there was an increase in the number of citations to engagement in studies and a reduction in the number of citations to discipline. Finally, we found differences in the reasons for rejection, with an increase in the number of citations to the lack of engagement in the studies, and a reduction in the number of citations to the indiscipline. The results suggest different patterns of acceptances and rejection along the different educational levels, which can be used to delineate interventions that aim to deal effectively with the behavior of the people involved, creating more reforcing interactions for students and teachers and socially skilled repertoires in students.