Banner (American Beauty; In Full Flower; etc.) offers here a joint biography of two major figures in American anthropology. Ruth Benedict and Margaret Mead met in 1922, when Benedict was a teaching assistant and Mead a student at Barnard College. Two years later, they were lovers. From the 1920s until Benedict's death in 1948, they remained friends and intellectual collaborators. For each, anthropological research and personal experience were interconnected; not only did a variety of co-workers become lovers and friends, but their sexual experiences shaped their theoretical positions on such questions as the "normalcy" of heterosexuality or the role of culture in defining deviancy. Banner's is the first work to use previously restricted private letters and papers of Mead and Benedict. She also draws heavily on recent decades of writing on lesbian history and queer theory. The results are uneven, mostly due to Banner's determination to find sexual abuse and lesbian subcultures in Benedict's youth and same-sex erotics in Mead's girlhood. Banner's "gaydar" works better when analyzing the variety of relationships the two women formed as adults, especially the way their own attractions morphed into fieldwork theorizing. While Banner plays fast-and-loose with some sources, this chronicle of the lives of two modern anthropology titans is bound to raise considerable academic interest. 28 b&w illus. not seen by PW. Agent, Nikki Smith. (Sept. 17)