Modernization theory states that changes to women’s socioeconomic position explains why women in younger cohorts are generally more supportive of the left – the political gender gap. Cross-national differences in the gender gap have been ascribed to differences in labour-force participation, marriage, and divorce rates; but individual-level studies struggle to explain political gender gaps using factors such as labour-force participation, education level, and marital status, especially for younger cohorts. This study attempts to explain this contradiction in the literature on political gender gaps by using longitudinal panel data from different European countries to directly measure the gendered relationship between certain life-course events and political attitudes/behaviours. First, we expect that individual changes in respondents’ socioeconomic position (including work and education) and civil status over the life course impact respondents’ economic attitudes and political preferences more strongly for women than for men. Second, we expect that these effects differ between countries and across generations, depending on the country’s and generations’ female labour-force participation, marriage and divorce rates, and gendered division of care work. These hypotheses are tested using household panel data from Germany (G-SOEP, 1984-2019), Switzerland (SHP, 1999-2019) and the UK (BHPS/UKHLS, 1991-2019), for different generations. The insights of the study contribute to the understanding of the formation of contemporary gender gaps across European countries, the relevance of modernization theory to explain this phenomenon, and how changes in socioeconomic and civil status over the life course impact individuals’ political preferences differently for men and women across different generations.