Across the world, public opinion about homosexuality varies substantially. While residents in some nations have embraced gay rights as human rights, in other countries, very few people find homosexuality acceptable. Why are there such big differences in attitudes about homosexuality? Using survey data from almost ninety societies, this book shows that cross-national differences in how residents view homosexuality can largely be explained by three country characteristics: the strength of democratic institutions, the level of economic development, and the religious context. While these factors can explain a lot of the differences across the world, the way they shape attitudes within individual nations varies substantially. Each country has a different story to tell about how these forces affect public opinion. Country case studies, a content analysis of newspaper articles, and in-depth interviews are used to unpack the characteristics working within individual and key sets of nations. Attention is given not only to demographic and country characteristics that shape public opinion but also to the way these factors work within specific countries and combine with a nation’s unique history and social context to shape attitudes, laws, policies, and enforcement regarding homosexuality.