> Second, what do you consider people with neither or both kinds?
Male/female is determined by chromosomes, either XX or XY.
Male/female is determined by chromosomes, either XX or XY.
This isn’t true legally (where “sex” is really an ascribed gender assigned at birth and possibly updated later for a variety of reasons) or medically (since an individual with a 46,XX karyotype can be male or female medically, as can an individual with a 46,XY karyotype.)
Seriously however, any link to where this is specified in the way you claim it to be? How does it see SRY gene disorders? If your child is a daughter to you but technically has XY, will the law mandate you to declare her as a son? etc.