Studies on "favoritism in the classroom" or the "teacher's pet" phenomenon often explore the psychological impact on student motivation and peer dynamics. You can find such papers through Google Scholar Classroom Management Guides:
In her guide The Teacher’s Pet (often shared in educator circles as “Kristal Summers The Teacher’s Pet”), Kristal Summers flips the old “teacher’s pet” stereotype into a framework for building mutual respect, not favoritism. Kristal Summers The Teacher S Pet.rar
If you are looking for actual teaching resources or research papers on the theme of student-teacher relationships or "teacher's pets" in a pedagogical sense, you may find the following types of "useful paper" or resources helpful: Academic Research: Studies on "favoritism in the classroom" or the