One voter out of two who casted a ballot in 2012 were not eligible to vote in 1981, and one fifth were not even born at this time. In 1981, 46% of the electorate were born before the Second World War. They count for only 15% of the voters in 2012. Generational renewal is a massive phenomenon, hardly taken into account in political sociology, since scholars, pundits and politicians seem more concerned by the aging of population. Yet cohorts matter for understanding the relationship to politics and politicians evolved and how political participation has been transformed. It is also the case for values and values system or political leaning and vote. In this blog various pieces of evidence of the impact of generational renewal will be published about France and various European and North American countries. They will be based on polls and surveys conducted since the 1950’s.