Comparative psychological studies in Africa have highlighted regional variations in mental health outcomes, educational attainment, and socio-economic factors. However, few studies integrate both qualitative and quantitative methods to provide a comprehensive understanding of these differences. The study employs a multi-informant design combining quantitative surveys (N=1000) with qualitative interviews (n=50). Data collection covers four major Nigerian regions: North, South, East, and West. Qualitative data are triangulated to ensure robustness and depth. The findings indicate a significant regional disparity in educational achievement scores, with the South region outperforming others by approximately 15%. Additionally, qualitative interviews revealed that cultural stigma surrounding mental health issues is more pronounced in the North region. This study underscores the importance of considering both quantitative and qualitative data to capture nuanced variations across regions. The integration of methods provides a more holistic view of psychological profiles in Nigeria. Future research should continue to utilise mixed-methods approaches, particularly in underrepresented areas like rural Nigeria where regional disparities are most pronounced. Policy makers can use these findings to tailor interventions that address specific regional challenges. Nigeria, Mixed methods study, Comparative psychology, Educational attainment, Mental health