To answer this question we need to discuss three different things: Biological sex (body characteristics), Gender expression (how we communicate our gender to the world), and Gender identity (our sense of self).
Biological sex refers to the different types of body parts (anatomy), chromosomes , and hormones present in a person. Typically, most folks are either “female-bodied” or “male-bodied,” but sometimes people have a blending of features or in-between characteristics and may be referred to as intersex. The most subtle forms of intersex (such as an XX person with typical female body parts but a very high testosterone level) seem to affect about 1% of the population but the more significant differences (such as a person with XY chromosomes but female genitalia or a person with “in-between” genitalia) affect about 1 in 5000 people. Note: some people use “biological sex” interchangeably with “gender,” but these are actually distinct concepts.
“Gender” refers to the ways we express ourselves as a woman or man (or something different) through appearance, behaviors, and actions. Also called “gender expression” or “gender presentation,” this can include things like wearing dresses and painting your fingernails versus playing with trucks and wearing baseball caps. These are social norms (and stereotypes) for what’s seen as appropriate or expected behaviors for women vs. men. Because these ‘rules’ are arbitrary, they change over time as society changes. For example, in the U.S. in the early 1900’s, magazines talked about how blue was the most suitable color for girl infants, and pink was for the boys! At that same time, it was scandalous for women to wear pants! Gender norms change over time.
One thing that unfortunately doesn’t seem to change is that gender non-conformity (not following these gender-based expectations), is often met with confusion or even anger. Some people are very attached to these arbitrary rules and get upset if they’re not followed. So, it’s important to realize that these gender norms are not fixed or biologically determined in any way. They are purely a cultural construct.
“Gender identity” refers to one’s sense of self and is an internal feeling of being a man, a woman, non-binary, or perhaps something different. For those whose gender identity “lines up with” their biological sex (referred to as “cisgender” folks), this may not seem to be something separate. (Example: “Of course I feel like a woman – look at me, I am one!”) But the experiences of other people tell us that, in fact, gender identity is a unique and separate thing from one’s biological sex. Some people’s bodies are one way, yet their brain and sense of self is something different. This is what’s usually referred to as being “transgender.” We’ll be posting more about that topic soon.Note: NONE of these three things is about sexual and romantic attraction. That’s sexual orientation (e.g. gay, straight, bi, etc.) and is about how you feel about OTHERS. 👨❤️👩 Gender is about who YOU are and how you express yourself.
Also note: Intersex and transgender are NOT the same thing! Intersex refers only to someone’s body characteristics or biological sex. Transgender refers to someone’s gender identity not being aligned with what is typically seen for a person with that biological sex (look for a post with more on that soon!).
Bottom line: The way our society uses the words “sex” and “gender” creates a lot of confusion. There are actually three distinct concepts here – biological sex, gender expression, and gender identity. Much of the time, those three “line up” fairly well in people (so they might not think of them as separate). But for some people they differ. Using specific language is then crucial for understanding.
Why is pink for girls and blue for boys? (Includes references on changing norms over time.)
Helpful glossary of gender-related terms from NPR
What determines biological sex, from TNG
Gender identity vs. Gender Expression
What does Transgender mean, from American Psychological Association