Why oh why do some people struggle to define what a woman is ?
It depends on what the context is. The simple, men and women model is appropriate for most considerations.... But in some contexts, this oversimplified model must be extended. There are many different ways in which it can be extended, depending on what the question at hand is:
• Including age: boys, men, girls, women. And then, we have to wonder what defines the cutoff. Is it a certain age that applies across the board? (ie legal adulthood definitions for voting, driving, drinking, etc.) Perhaps sexual maturity (for which multiple thresholds could be defined), which would make sense when considering sexual activity/risks etc.
• For sports. It might make more sense to look at hormone levels. (Even without administered hormones, genetics alone doesn't necessarily dictate which hormones are produced and at which levels, and even then, the bodies might have atypical responses to hormones. For example, some people are born with XY genes, but no testes, and therefore develop as female https://rarediseases.org/rare-diseases/swyer-syndrome) If we consider administered hormones, then does a female who transitions to male compete as a female or a male? What about someone who has developed as a male and then transitions to female? Should there be more than two categories, or maybe only one? The rules should be decided for each competition, well in advance of the actual competition.
• What about for medical treatment? Just M/F is terribly oversimplified, especially when it comes to treating diseases related to sex. Ideally, doctors should know the genetic makeup, hormonal history etc. of each patient. Think of it this way: a flashlight (torch) can be on or off (simple enough, no?), but if it is off, one must know whether the switch is off, if it has batteries in it, if the batteries are installed with the correct polarity, if the circuit is broken etc. It is similar for human bodies. There are so many interconnected systems, and an apparent error can have many different causes (disease, mutation, toxic exposure, injury, etc.)
• Definitions base on body parts suffer from complications such as surgeries (as alancalverd pointed out). And sometimes, people are born as intersex, with genetalia that are not obviously assignable as strictly male or strictly female. (going off of neilep's tagline, some people are only partially inside out) https://www.healthline.com/health/baby/what-does-intersex-look-like
The following users thanked this post: neilep