Sorry, that's just not true. Different TECHNICAL aspects of physical gender also include secondary sex characteristics, chromosomes, hormones, and brain sex. That still leaves out gender identity from a psychological point of view.
A male may be born without a penis (penile agenesis). Doesn't make him any less male. Androgen insensitive women have male chromosomes but have female genitalia.
To the topic, the binary is a valid construct because it fits a super-majority of the population. TG/TS/IS are exceptions and, as Bree, Julia and others have pointed out, it describes even a lot of those. I also like Bree's care in separating out expression from identity. I.e., identity may be stated to be even more binary than expression, which is largely cultural anyway.
Lea





