The debate over whether children learn better in single-sex or mixed school environments has persisted for decades without producing a clear consensus, in part because the evidence is genuinely mixed and the outcomes depend heavily on factors beyond gender composition alone. Both positions, however, have coherent arguments behind them. Advocates for single-sex schooling argue that separating boys and girls removes the social dynamics and peer pressures that can distort academic choices and undermine confidence — particularly for girls in science and mathematics, and for boys in literacy and the arts. Research from some single-sex institutions suggests that students are more willing to engage with subjects outside traditional gender expectations when they are not performing their gender identity for peers of the opposite sex. Classroom dynamics in single-sex environments may also be easier to manage, allowing teachers to tailor their approach to the particular learning patterns and communication styles that research associates, cautiously, with each gender group. Proponents of mixed schooling counter that the primary purpose of education extends beyond academic performance to preparation for adulthood in a diverse society. Children who spend their formative years in single-sex environments may emerge less practised in the everyday collaboration and communication across gender lines that adult professional and personal life requires. Mixed schools also challenge gender stereotyping in real time, rather than reinforcing it by segregation, and provide a social environment that more closely mirrors the world students will inhabit after graduation. Equality advocates often point out that the resources and expectations available in single-sex schools have historically varied significantly by gender, raising questions about equity that mixed schools structurally avoid. In my view, school quality, teaching standards, and institutional culture matter far more than gender composition. A well-run mixed school produces excellent outcomes; so does a well-run single-sex school. Parents and communities should focus their attention on those deeper factors rather than treating gender composition as the primary variable in educational quality.