Designed as a synthesis of concepts familiar to students having studied the earlier Minnesota Project English units or as an introduction for other students, this unit for grade 12 treats the role of language in the social and psychological development of man. Alternative introductions to the unit are provided: one concentrating on definitions of language, man's unique symbol-making ability, and the importance of language; the other dealing with what is meant by "knowing" a language. The unit then develops concepts related to the role of language in social interaction, language as a reflection of culture, the relationship between language and reality, the process of communication, interferences based on a person's language or dialect, levels of usage, and stereotyping by language. The concepts are presented through sample lectures, discussion questions, and suggested readings; additional readings for gifted students and a bibliography on the role of language are included. (JS)