The idea of there being only two genders—male and female—actually started in Western society around the 18th century, when rigid gender roles were tied to social, religious, and cultural expectations. But many other cultures across history have widely accepted the concept of more than two genders. For example, Indigenous cultures in North America recognize Two-Spirit people, and in South Asia, hijras have been part of the cultural fabric for centuries.

Here’s the key: gender and sex are not the same thing. If that feels confusing, don’t worry—you’re not alone! Let’s break it down so it’s simple and easy to understand.

Sex: What You’re Assigned at Birth

Let’s start with sex, sometimes called sex assigned at birth or biological sex. This refers to the physical characteristics you’re born with—things like reproductive organs, hormones, and chromosomes (the X and Y ones you might remember from biology class).

• Typically, a baby is assigned male or female at birth based on visible anatomy.

• In some cases, a baby may be born with a mix of characteristics, which is known as being intersex.

Sex chromosomes play a big role in this assignment:

• XX chromosomes are typically associated with female bodies.

• XY chromosomes are typically associated with male bodies.

But here’s the thing: sex is more complicated than just these two letters. Hormones, anatomy, and even how chromosomes express themselves can vary widely, so sex isn’t always as straightforward as people think.