When a teacher has a similar personality to a student, it can bias the teacher’s judgement; that’s the finding of a recent study in Germany.
The researchers looked at 94 teachers and 293 of their students, all of whom were in Grade 8 (Year 9). Teachers and students undertook a personality survey, and researchers compared the performance of the students on maths and reading comprehension tests. Teachers were also asked how well they thought the children would do in the test generally (a global judgement) and on specific questions (a task-specific judgement).
The results showed that when teachers and students had a similar personality, the teacher tended to give the student a higher rating on the global judgement. However, the similarity had little impact on the teacher’s task-specific judgement. The researchers suggest that, when considering a global judgement, teachers do not consider the specifics of how the individual student might approach a test and instead fall back on more subjective opinion.
Source: Personality similarity between teachers and their students influences teacher judgement of student achievement (2015), Educational Psychology.