This influence of age has two different elements. One is “life-cycle effects,” meaning that people tend to be progressive in their youth, and become conservative as they get older. The other element is “generational effects,” implying that each generation of voters, as they have been raised under different social environments and have gone through different political experiences, tend to have different values systems and ideological orientations. In particular, the post-materialistic values found mainly among the younger generations, as opposed to the materialistic values of the older generations, are believed to be responsible for the relative progressiveness of the young voters