Because there is a difference.
People tend to use the word “gender” to mean any one of these meanings. But as our society grows and we learn more about the self, we get to a point where we need more clarification. Otherwise things can get confused and misconstrued.
I may not have the authority to talk about this because I am no scientist, and I am no psychologist. But I definitely have the knowledge, as I am somebody who not only has done a lot of studying into sex and gender, but I have also lived through my own struggles. That’s pretty much what forced me to learn.
Sex is a biological term and is what you were born as: male or female. It is determined by your chromosomes so it is not something that can be changed, despite misleading terms like “sex change”. I have to stress this because it is important. When it comes to medical documents, like for a hospital or doctor’s surgery, you should put your sex rather than gender identity, and have in your notes what your gender identity is if it doesn’t match your sex. I say this because males and females are susceptible to different illnesses and diseases.
Gender Identity is a psychological term that is really who you are on the inside. This is what is usually meant when people say “gender”. This is more whether you are a man, woman, NB, etc. and is basically up to how the individual feels.
Gender is a psychological term and although it has about 50 different meanings (slight exaggeration), it is widely used in psychology to refer to personality traits: masculine, feminine, or androgynous.
To summarise, every person has a sex, gender identity, and gender. It is never black and white, gender is such a wide spectrum so people can fall anywhere on it. To be completely honest, it doesn’t really matter what somebody is.
On a final note, I know this post was very brief, and only just scratches the surface, and there is a lot more to it than what I have written. This will not be my last post on gender. There is a lot more to say and I think everybody could do with learning more about gender after the way the media has dragged the word through the dirt.
Also, please comment if you think I got something wrong, if you have more to add, if you have a story to share, whatever. I am interested in any feedback.
Farewell, until we meet again.