This paper examines a possible relationship between the number of mother tongues undergraduate students studying at a Swedish university speak and their academic performance. It describes the study conducted on the cohort of sixty-one students enrolled in two primary school teacher-training programs with some being native monolinguals, who have only been exposed to one mother tongue, and others being either native bilinguals (exposed to two mother tongues) or native multilinguals (exposed to more than two mother tongues). Despite the initial hypothesis that there might be a positive correlation between the number of mother tongues the students have a command of and their academic performance, the study, which focused on the variables such as students’ grade average, their fail rate, the extent to which they have used their mother tongues at home, as well as other factors, shows the opposite trend. That is, the students with only one mother tongue manifest greater academic achievements than those with two or more. Taking into account multiple other studies pointing out the positive relationship between bilingualism (multilingualism), cognitive development of children and their academic performance at the early age, the paper also poses the question of why this correlation has not been observed in the study involving young adults. In this respect, it also considers the possibility of some other factors being involved that override the initial cognitive advantage that bilinguals (multilinguals) manifest over their monolingual peers at the earlier stages of their lives.

Keywords: Academic performance, native bilingualism, native multilingualism, cognition, cognitive development, equality in education.