In 2018 the General Social Survey began releasing data on respondents' self-identified gender.[1]
Historically surveys have only offered options for respondents to indicate being either male or female.[2] More inclusive surveys may offer more options.[2]
Some respondents will not want to indicate being either male or female and will wish for additional options.[3]
Sex and gender are important demographic characteristics to understand in social research, but for information on these things to be meaningful, researchers must be thoughtful in collecting the data.[4]
^Westbrook, Laurel; Saperstein, Aliya (10 July 2015). "New Categories Are Not Enough". Gender & Society. 29 (4): 534–560. doi:10.1177/0891243215584758. S2CID85520200.