Ms. Cao found that most of the people she met shared that concern over authenticity, that question of what makes a “real” Asian.

“It kind of indicates there’s only one real truth, but talking to them made me realize that there’s no one way to be Asian or American — or just a person,” Ms. Cao said. “It’s so important for us to embrace our differences.”

Other interviewees agreed: Mathew Luce, who was adopted from Indonesia and lives on Roosevelt Island, doesn’t take insults or ignorant comments to heart. “I’m proud that I’m Asian, and I’m proud that sometimes I act white,” he told Ms. Cao. “It’s just me. That’s how I grew up.”

Una, whose parents asked that her last name not be published, was only 9 when Ms. Cao photographed her at home in Brooklyn. But she had been wondering about her identity for a while. With her family’s support, she already had contacted a Korean adoption agency to search for her biological parents, but she was told she was too young to open her case.

If she can’t find them, she told Ms. Cao, she would be content knowing she tried.

Ms. Cao hopes to expand the photo essay to include people of other ethnic backgrounds. She said adoptees might not feel the need to address race at home, but “when they grow up and step into society, race is just a thing that nobody can escape.”

Her project has also helped Ms. Cao come to terms with her own identity. “I’m not trying to force myself to fit any categories,” she said. “Now I think I’m really comfortable, just knowing that nothing can take away from my Chinese roots.”