High levels of economic and physical security encourage a shift from Materialist to Postmaterialist values. This makes people more favorable to a variety social changes, grows people’s acceptance of gender equality and homosexuality, and leads a shift from “pro-fertility norm” (emphasizing traditional gender roles and stigmatizing any sexual behavior not linked with reproduction) to “Individual-Choice Norms” (supporting gender equality and tolerance of homosexuality). This chapter provides evidence for the claim that economic development is conducive to the emergence of individual-choice norms by showing that these norms are more widespread among the publics of rich countries than poor ones. While basic cultural norms don’t change immediately and change happens slowly even in economically secure societies, intergenerational population replacement has gradually made individual-choice norms increasingly acceptable in high-income societies. The shift from Pro-fertility norms to Individual-choice norms has reached a tipping-point where conformist pressures have reversed polarity and are now bringing major societal changes such as legalization of same-sex marriage.