“The Silent Revolution in Europe” was the first presentation of the intergenerational value change hypothesis. It argued that the publics of postindustrial societies are shifting from giving top priority to “Materialist” goals such as economic and physical security to placing increasingly strong emphasis on self-expression and the quality of life. Throughout history, survival has been insecure for most people, forcing them to give top priority to survival needs. But in advanced industrial societies, the economic miracles of the postwar era and the emergence of the welfare state gave rise to conditions under which much of the postwar generation grew up taking survival for granted; they give increasingly high priority to “Postmaterialist” values such as belonging, self-expression, and free choice. Because people's basic values do not change overnight, those who experienced the insecurity of World War I, the Great Depression, and World War II would continue to emphasize Materialist values, but we would expect to find an intergenerational shift toward Postmaterialist values.

If this is true, the implications are far-reaching. Quality of life issues should gradually displace class-based issues such as income redistribution and state ownership of industry as the main axis of political conflict. New types of political movements and parties should emerge to champion the new issues. Social class voting should erode, as support for change shifts from its traditional working-class Materialist base to Postmaterialists from relatively secure middle-class backgrounds.

This hypothesis grew out of analysis of the May 1968 protest movement in France, which I originally approached from the perspective of Marxist class conflict; that approach was widespread at the time and dominated the rhetoric used by the participants themselves. But survey data blatantly did not fit the implications of a Marxist model: in the aftermath of the May events, workers who had previously voted for the Left shifted to support the Gaullist regime, whereas young, predominantly middle-class students constituted the main base of support for radical social change. A large share of the public had taken part in various protest activities, and their responses to the question, “What did you hope to attain?” revealed large differences between the motivations of older and younger generations, and between economic strata, that led me to develop the intergenerational value change hypothesis.

This article tested that hypothesis against 1970 survey data from six Western countries. I found the predicted intergenerational differences: among those age 65 and older, Materialists were 12 times as numerous as Postmaterialists across the six countries; but among the postwar generation, Postmaterialists were slightly more numerous than Materialists. With data from a single time point, it was impossible to determine whether these age differences reflected intergenerational value change (which implies gradual but pervasive value change) or life-cycle differences (which implies that the young would eventually become just as Materialist as their elders, so that no overall value change would occur).

Initially, critics of the intergenerational value change thesis argued that the observed age differences merely reflected life-cycle effects. But today, cohort analysis of data covering three decades demonstrates that the respective birth cohorts did not become more Materialist as they aged: they remained fully as Postmaterialist as they had been in 1970. Moreover as younger, relatively Postmaterialist cohorts replaced older, relatively Materialist ones in the adult population, the predicted intergenerational value shift occurred: in 1970, Materialists were four times as numerous as Postmaterialists across the six nations, but by 2000, Postmaterialists outnumbered Materialists in all six countries (Inglehart and Welzel 2005). The central issues of political conflict have shifted, with the rise of environmentalist movements, the women's movement, gay liberation, and other lifestyle movements. Moreover, social class voting has declined in most advanced industrial societies; in the last two U.S. presidential elections, for example, the vote polarized much more strongly on lifestyle issues, such as abortion and same-sex marriage, than on social class.

When the postwar generation first became politically relevant around 1970, it manifested itself as student protest. Today, generational cleavages are less striking. The 1970s adage, “Don't trust anyone over 30” would translate into “Don't trust anyone over 65.” But value-based polarization continues, and recent research demonstrates that Materialist/Postmaterialist values are just one indicator of a much broader cultural shift from Survival values to Self-expression values. This shift is bringing changing values concerning gender roles, sexual orientation, work, religion, and child-rearing—and it is conducive to the spread and flourishing of democratic institutions (Inglehart and Welzel 2005).