This document discusses key concepts related to human cultural variation, social differences, social change, and political identities. It defines cultural variation as differences in social behavior between cultures around the world. Social differences are described as the complex variations between individuals based on social characteristics like class, role, culture, age, ability, and sex. Social change refers to significant alterations over time in cultural values and norms that result in profound social consequences. Finally, the document explains that identity politics focuses on the interests and perspectives of groups with which people identify, such as those organized around race, class, religion, gender, ethnicity, ideology, sexual orientation, culture, and language.