#[0] Dr. John Money introduced the concept of gender in the mid-20th century, specifically in the 1950s and 60s. His work focused on gender identity and expression in intersex individuals and was a foundational shift in thinking about gender as something separate from biological sex. Since then, the concept of gender has evolved and been refined by many scholars and activists, leading to a more nuanced understanding of the complex interplay between biological sex, gender identity, and cultural and social expectations.