The common themes explored in the UPSC Mains Sociology optional paper often include social stratification, culture, family dynamics, and the impact of modernization. Examining social institutions, their functions, and interactions within society is essential. Aspirants analyze the effects of globalization, development, and policy on societal structures. Themes like social change, inequality, and community are frequently discussed, emphasizing the importance of theoretical frameworks and current social issues. Understanding these themes is crucial for coherent and comprehensive answers.