Linguist and anthropologist, born in Lauenburg, Germany. His family moved to the USA when he was a child, and he studied ethnology and American Indian languages at Columbia University, where he was influenced by Franz Boas. One of the founders of ethnolinguistics, he is best konwn for his work on the languages of the North American Indians. His insights into the effect that the grammatical structure and vocabulary of a language may have on the way its speakers perceive the world were developed by his pupil Benjamin Lee Whorf, and came to be known as the Sapir-Whorf hypothesis . After working at the Canadian National Museum (1910-25), he became professor of anthropology and linguistics at Chicago (1925-31) and Yale (1931-39).