Final answer:
Margaret Mead was the early anthropologist who distinguished between biological sex and gender roles in her 1935 book 'Sex and Temperament in Three Primitive Societies.' Her work helped to pave the way for a broader understanding of gender identity and cultural constructions of sexuality.
Step-by-step explanation:
The early anthropologist who wrote the book Sex and Temperament in Three Primitive Societies and was the first to distinguish between biological sex and gender roles was Margaret Mead. She conducted research on gender in several societies in New Guinea and found that gendered behaviors were not strictly grounded in biological differences but varied significantly across cultures. In her seminal work from 1935, Mead detailed her findings on the Arapesh, Mundugumor, and Tchambuli (now known as Chambri) societies, each with its own unique interpretation of gender, challenging the Western binary gender norms.
Before Mead's research and the later work by Dr. Alfred Kinsey, perceptions of sex and gender roles were largely based on limited empirical research, with ideas often propagated through personal experience or peer discussions rather than scientific inquiry. Mead's ethnographic work paved the way for a more nuanced understanding of the complexities surrounding gender identity and the cultural constructs of sexuality.