@shivian The survey "measured gender expression by asking every surveyed adolescent one question about how people at school viewed their physical
expression of femininity and masculinity.

A person’s appearance, style, dress, or the way they walk or talk may affect how people describe them. How do you think other people at school would describe you?
• Very feminine
• Mostly feminine
• Equally feminine & masculine
• Mostly masculine
• Very masculine"

http://healthpolicy.ucla.edu/publications/Documents/PDF/2017/gncadolescents-factsheet-dec2017.pdf