Book excerpt: How many sexes are there? What is the relationship between sex and gender? Is gender a product of nature, or nurture, or both? In Beyond the Binary, Shannon Dea addresses these questions and others while introducing readers to evidence and theoretical perspectives from a range of cultures and disciplines, and from sources spanning three millennia. Dea’s pluralistic and historically informed approach offers readers a timely background to current debates about sex and gender in the media, health sciences, and public policy.