The enduring impact of democracy on political behaviour: voting on European integration in the European Parliament

This paper explores how early-life exposure to democracy shapes the voting behaviour of Members of the European Parliament (MEPs). Drawing on the ‘impressionable years’ hypothesis, we analyse 30 years of roll-call votes (EP1–6) and find that MEPs who experienced more democratic regimes between ages 18 and 25 are significantly more likely to vote in favour of EU integration. These results are robust across specifications and supported by MEP survey data. Our findings highlight the lasting influence of early institutional environments on elite decision-making and offer important insights for understanding the long-term impact of democratic backsliding and EU enlargement.