Davis did her best to support her daughter, letting her cross gender barriers despite occasionally feeling uncomfortable. Learning how to talk to her child about gender issues and how to leave room for a variety of identities to develop led Davis to write "Tomboy: The Surprising History and Future of Girls Who Dare to Be Different," which not only explores how tomboys fit into our evolving understandings of gender identity and expression but also "how and why we've ordered the world by gender, and who benefits," Davis said. Incremental shifts in American culture — including greater use and acceptance of they/them pronouns, more widespread support for transgender people and the recent Supreme Court ruling that protects LGBTQ people against workplace discrimination — reflect society's expanding acceptance of a wider spectrum of gender identities and expressions. But we must reckon with the realities of society's present-day expectations for children, even as we push to create spaces that are more open to all. Until then, social pressures that force people into what Davis called "ridiculously narrow boxes" will continue to damage everybody. This is not just a tomboy or an LGBTQIA+ issue, she said. "We're all impacted by the negative consequences of rigid gender roles." This conversation has been edited and condensed for clarity. CNN: In your book you describe how, in recent years, we've seen parents and society at large ascribe to stricter gender roles than in earlier eras. Why? Lisa Selin Davis: Today in this country, childhood is more hyper-gendered than ever before. The primary driver of gender rigidity is the brutality of capitalism. This approach has been a brilliant capitalist strategy for selling twice as many things. No longer could families rely on sharing hand-me-downs between their sons and daughters. CNN: How did that transformation take place? In your book you cite the 1980s as a turning point. Can you explain why that is? Davis: The last tomboy heyday in this country was the 1970s and early '80s. A dominant strain of feminism changed our ideas of what was acceptable — and even preferable — for girls. Lots of girls wore short hair and what were called "unisex" clothes: corduroys or sports shorts with stripes on the side and T-shirts, tube socks and Keds. The Sears catalog even had boys-to-girls size-conversion charts. Messages everywhere suggested that girls deserve equality with boys and access to their worlds. But that model of equality emphasized emulating boys. Then, in the Reagan era, feminist backlash began putting an end to that. The rise of "girl power" promoted empowerment through femininity. That was liberating for some girls who weren't tomboys and didn't want to be "masculine," but constraining for others who were not interested in, or couldn't measure up to, traditional notions of femininity. CNN: How does our modern-day understanding of "sexuality" as distinct from "gender" play a part in the role expecta