This study investigates the relationship between gender and student attitudes toward mathematics among Form Three students in Keiyo District, Kenya. While national examination data consistently reveal lower performance among girls compared to boys, this research challenges the notion that such disparities are purely academic or ability-based. Guided by Interaction Theory, which emphasizes the role of socialization and interpersonal influences, the study examines whether the observed performance gap reflects deeply rooted societal and educational biases. Utilizing a descriptive survey and ex-post facto design, the research sampled 300 students (150 boys and 150 girls) and 15 mathematics teachers across stratified public secondary schools. Data were collected via structured questionnaires and analyzed using descriptive and inferential statistics, including Chi-square tests. The findings reveal a statistically significant relationship between gender and attitudes toward mathematics, with boys displaying more positive attitudes than girls. These attitudes are not merely personal but reflect broader cultural messages and classroom practices that often favor male learners. The study concludes that while test scores may appear objective, they are embedded in social contexts that shape and skew outcomes. It recommends targeted teacher training, inclusive pedagogy, and gender-sensitive policies to create a more equitable mathematics learning environment.