Culture is understood as a collection of socially transmittable information, whereas group is a collection of people. Analytically separated, cultural and social identities are conceptually distinct—an individual’s identification with and self-definition of who one is in relation to cultural elements and social groups. We argue in this article culture shapes identity processes and intergroup relations via metaculture, i.e. cultural information about cultural information. Metaculture includes diversity ideologies—ordinary people’s lay conceptions of “culture,” which have organized the public discourse about cultures and their interrelationships. The diversity ideology of colourblindness essentializes humanity as a group, but disregards culture and cultural differences among social groups. Multiculturalism essentializes both culture and group, regarding culture and group as inexorably linked, and treating a group’s culture as its essence. Polyculturalism eschews essentialism, separates culture from a social group, regarding culture as ideas and practices that can be adopted by anyone regardless of their group memberships. Diversity ideologies influence our discourse on and experiences of culture, group, and identity in our lived experience, which in turn shape intergroup and identity processes. The implications of this analysis are discussed within the historical context of increasing super-diversity and changing nation-states against the backdrop of globalizing humanity.