Hurston, Ruth Benedict, Margaret Mead and Ella Cara Deloria are the other central figures in King’s book; like Boas, all of them came to see anthropology “not just as a science but also as a state of mind.” His ideas were particularly appealing to women who chafed at the patriarchal order. Men were constantly spouting specious and self-serving theories of what was natural; here was a man suggesting that those things might not be so natural after all.

Image Charles King, whose new book is "Gods of the Upper Air," about the anthropologist Franz Boas's influence on ideas about human diversity. Credit... Miriam Lomaskin

Boas became a pivotal figure in the discipline — though at first he was marginal, an itinerant scholar who had a hard time landing a secure position in the United States. For a while he held a curatorship at the relatively young American Museum of Natural History, but the museum was a creature of the establishment, hosting grand conferences on eugenics and showcasing displays on the “ill effects of racial interbreeding.” The then-dominant school of anthropology propped up a narrative tracing “the stages of human culture,” from “savagery” through to “barbarism” and finally to “civilization.” Mainstream scholars insisted that white supremacy was justified by head measurements and heel length.

Overturning this terrible science required more than fervent criticism. King, a professor at Georgetown and the author of several books about Eastern Europe and the former Soviet Union, describes how Boas tried to use the methods of physical anthropologists against them, deploying calipers and eye-color meters to show that the children of immigrants, born in the United States, had more in common with other American-born children than with the national groups represented by their parents. But Boas’s work in the field only accounted for part of his influence. It was mainly through his teaching at Columbia and his nurturing of a new generation of anthropologists that he changed how many Americans saw the world and, consequently, themselves.

King weaves in the stories of Hurston and Deloria, who used what they learned from Boas to study their own communities. Hurston’s “Mules and Men,” a book about African-American folklore, included an immersive account of her return to the Florida she left during the Great Migration, and her experience as not just an observer of the community but a participant in it. Deloria, who was born on the Yankton Indian Reservation in South Dakota, was a co-writer with Boas of “Dakota Grammar”; she worked on it for a decade, explaining to Boas the delicate process of deciding on the right gifts to coax candid talk from her informants. “To go at it like a white man, for me, an Indian,” she said, “is to throw up an immediate barrier between myself and my people.”