What’s the Difference Between Sex and Gender?

Medically Reviewed by Gabriela Pichardo, MD on September 13, 2023
4 min read

People tend to shy away from this question. The answer is often murky, and different people will have their own definitions of sex and gender. It’s about as simple as comparing an apple and a car.

Sex, gender, and sexual orientation are all part of the formula that helps you identify who you are. But they aren’t as concrete as you might think. 

Sex is generally determined at birth according to the baby’s chromosomes, gonads, and anatomy. These three features are used to determine biological sex.

Chromosomes. These are tiny structures in the cells that house your unique DNA. A pair of chromosomes called the sex chromosomes determines whether you are male or female. Females have two X chromosomes, and males have an X and Y chromosome.

Gonads. These are the primary reproductive organs. Males have testes and females have ovaries. These organs also secrete hormones that promote reproduction. 

Anatomy. Physical genitalia determine sex during the baby’s development. Genitals are the first of the characteristics that determine sex to develop in the womb. Genitalia are the primary sex characteristic, but secondary characteristics are considered, such as breasts, frame, and facial hair.  

The above parameters are not definitive. There can be slight variations along the way that will make a sex label inaccurate. Medically, there are three possible sexes assigned at birth: female, intersex, and male. 

Female. A person whose sex is female typically has the following traits: 

  • Two X sex chromosomes
  • Ovaries
  • The hormones estrogen and progestogen
  • A uterus, vagina, and vulva
  • Breasts, an “hourglass” figure, more body fat
  • A higher-pitched voice

Male. A person of the male sex typically has these traits: 

  • One X and one Y sex chromosome
  • Testes
  • The hormone testosterone
  • A penis and scrotum
  • Facial hair, a “triangle” figure, more muscle mass
  • A lower-pitched voice

Intersex. The term “intersex” describes a wide range of people that don’t meet 100% of the criteria for male or female sex. An intersex person is born with or naturally develops characteristics that aren’t considered exclusively male or female. These include variations in: 

  • Sex chromosomes
  • External genitalia
  • Reproductive system (gonads)

Because of the possibility for variations, "intersex" has become an umbrella term for a wide variety of people. This makes it clear that sex isn’t black and white. 

It’s easy to get lost in the weeds when discussing sex and gender. It becomes more complex when sexuality is dropped in. But it doesn’t need to be.

Sexuality is divided into three elements: who you’re attracted to, your sexual behaviors, and your identity. As with most things, descriptions of sexuality are vast and can’t be encompassed in a simple binary. 

Sexuality takes into consideration your sex or gender and the sex or gender of any partners. It’s important to know that your sex doesn’t predetermine your sexuality. Your sexual behaviors, who you’re attracted to, relationships, and personal identity, influenced by societal norms, and social stigmas, are the forces behind your sexuality. 

Some of the identifiers for sexuality (or sexual orientation) include:

  • Gay
  • Lesbian
  • Queer
  • Bisexual
  • Pansexual 

Gender is a multi-faceted social system. Gender is largely based on society and culture. There are some consistencies, but it can be concluded that gender is not predetermined based on sex. 

Gender roles. The backdrop of a discussion about gender is gender roles and gender assumptions. There are certain traits and roles that society expects people of each gender to fit into. 

Each culture has different gender roles. Gender identity and expression are derived from ideas about which traits and roles are perceived as masculine or feminine in that culture.

Gender identity. Arguably, the most important determinant of gender is your gender identity. This is the internal sense of self that states your gender, regardless of the sex assigned at birth. Some of the common gender identities are man, woman, nonbinary, and genderqueer. 

Cis or cisgender. The terms “cis” and “cisgender” are used to describe a person whose gender identity aligns with the assumptions their culture makes about members of their sex. A person who is assigned a female at birth and identifies as female is considered cis. 

Trans or transgender. A trans person’s gender identity doesn’t match the assumed characteristics of their assigned sex. A person who was assigned male at birth might feel that their identity and sense of self are aligned more closely with a female identity. 

Nonbinary. A person who identifies as nonbinary feels that their gender identity doesn’t align within the male/female division. "Nonbinary" is an umbrella term that represents a variety of people. There is no single nonbinary gender identity. 

Gender expression. This is how you express your gender identity. Gender expression (or gender presentation) is a combination of clothing, physical appearance, behavior, and mannerisms that convey your gender identity. 

Gender expression may be described as masculine, feminine, androgynous, or something else entirely. Gender expression will mean something different for every person. Not everyone will have the same perceptions, definitions, or identifiers.