Within the Caribbean, there has been a perception that students are underachieving in mathematics. This assessment has seemingly been based amongst other things upon the proportion of students who are successful in mathematics compared to other subjects in external examinations. This notion was investigated in a case study of secondary schools in Antigua and Barbuda. Statistical data showed that student achievement in the examinations "was" on average lower in mathematics than across all subjects, including English language. However, this finding was not "true" of students across all school-types, generally a proxy for social class in Caribbean settings. In particular, the mathematics achievement of students in single-sex schools was not far different from their performances in other subjects, but was markedly different from that of students in mixed-sex schools. This finding concerning school-type suggested at an underlying factor in many students' mathematics performance, as school-type in the Caribbean is predicated on students' home backgrounds. This paper reports on these findings, and sets out how the education system appears to reinforce and further exaggerate advantages and disadvantages of students' social and cultural histories. (Contains 1 note, 2 figures and 3 tables.)