This qualitative study has been done to 24 teachers and 72 students from various secondary schools in Penang, Malaysia, related to the effect of between class ability grouping (BCAG). Studies reported that BCAG triggered correspondence bias among teachers, which eventually affect them to show different perception and expectations towards high achiever classes (HAC) and low achiever classes (LAC) students. However, even teachers tend to expect HAC students not to be significantly involved in disciplinary problems; they still do, such as distrusting schoolteachers, paying less attention to in the classroom, doing external work during classes at school, and being blatantly arrogant to the teachers. Semi-structured interview have been utilized in order to collect the data, and two-cycled analyses method, namely In-Vivo and Thematic Analyses has been operated in order to analyze the massive amount of qualitative data. Findings of this study showed that the disciplinary problems among HAC are related to their self-esteem types due to locus of control difference, as well as bigger issues apart from the competition among themselves. School management system, BCAG itself, and reciprocal envy between HAC and LAC students, as well as their inclination towards tuition centers contributed to disciplinary problems among HAC students.