Though social sciences have devoted a great deal of attention to perceived inequalities, not much has been done to investigate how dissatisfaction with income inequality varies across subgroups over time. This study shows that income groups, educational groups and cohorts have moved in parallel since the beginning of the 1990s. Contrasting with the notion that post-scarcity generations should be more opposed to income inequality, it is also found that baby boomers are driving the generational dynamics of dissatisfaction with income gaps. These findings suggest that generation renewal will fuel tolerance for inequality, because of baby boomers leaving the scene and being replaced by younger cohorts not as sensitive to income differences.