Proportional reasoning is important for students' success in the learning and understanding of physics concepts. Key aspects of students' difficulty with proportional reasoning can be understood only when the social and cultural contexts in which they are embedded are considered. Hence, there is a need for a constructivist investigation of students' constructions of their difficulty and nonuse of proportional reasoning within their immediate social and cultural contexts. A constructivist and interpretive case study was carried out with six physics students from a coeducational senior secondary school, and this provided some insights into the association between cultural heritage, students' worldviews, societal expectations, authoritarianism, upbringing, customs and traditions, language, everyday life, and students' use of proportional reasoning in physics. Students were engaged with various proportional reasoning tasks during which multiple research techniques were employed to generate, analyze, and interpret data using the hermeneutic dialectic process and an emergent approach.