This document discusses human cultural variation and social differences. It defines cultural variation as differences in social behaviors between cultures, such as what is considered good or bad etiquette. Social differences are defined as differences between individuals based on characteristics like gender, socioeconomic status, and exceptionality. The document then explores specific aspects of cultural variation like religion, ethnicity, and nationality. It also examines social differences such as gender, socioeconomic status, and exceptionality. Subcultures within cultures and countercultures that reject mainstream values are also discussed.