What's the Difference Between Sex and Gender?

The IAAF has required Olympic gold medalist Caster Semenya to take medication to lower her testosterone levels—a demand she has actively fought against.
The IAAF has required Olympic gold medalist Caster Semenya to take medication to lower her testosterone levels—a demand she has actively fought against. / MARCO LONGARI/AFP via Getty Images

Though sex and gender are two words that are often used interchangeably, each one has distinct meanings and many different applications.

Biology vs. Society

In addition to the act of “having sex” (you would never say “having gender”), the word sex is used to define the biological designation given to a person at birth, based on things like visible body parts. So a baby born with a penis is labeled a male; a vulva means she is a female. Then there are cases of intersex individuals. According to NPR:

“In the area of 1 in 2000 people are born intersex. These individuals may have mixed genitalia, meaning some combination of ovaries and testes. This comes about either because ovarian and testicular tissue grow together in the same organ or because a ‘male side’ and a ‘female side’ develop in the body. Other intersex individuals may have genetically inherited chromosomal abnormalities such as congenital adrenal hyperplasia, which may result in masculinization of the genitals in people born with XX chromosomes, or androgen insensitivity syndrome, when the body doesn't respond to testosterone and a person has XY chromosomes and feminized genitalia.”

So what makes sex and gender different? Sex is biological; gender is a social construct. Gender relates to the attitudes, feelings, and behaviors that a particular society associates with being male or female.

The Case of Caster Semenya

The Greek-derived word hermaphrodite, which is defined as an organism having external male genitalia and the reproductive organs of a female, is sometimes mistakenly used to describe intersex individuals like Caster Semenya.

Semenya, the Olympic gold medal-winning track star from South Africa, was designated a female at birth and has always identified as a woman. But Semenya is thought to have a condition known as hyperandrogenism, which means that she produces exceptionally high levels of testosterone. As such, the International Association of Athletics Federation (IAAF) has required her to take medication to lower her testosterone levels and to prove she is not a "male" competing in a "female" sport—a rule that Semenya has actively fought against.

In June 2019, Semenya achieved a legal triumph when the Swiss Federal Supreme Court temporarily ruled against the IAAF and determined that the athlete did not need to submit to the organization's medication requirements, but the celebration was short-lived. In late July 2019, a second ruling sided with the IAAF's original regulation. Semenya issued a statement at the time, saying: "I am very disappointed to be kept from defending my hard-earned title, but this will not deter me from continuing my fight for the human rights of all of the female athletes concerned." While Caster continues to appeal her decision, she is now playing football in South Africa.

The Fluidity of Gender Identity

Many track and field fans believe Semenya has been targeted by jealous rivals and overzealous members of the IAAF because of her success. In an interview with Business Insider, Yale University cultural anthropologist Katrina Karkazis expressed concern that the issue in Semenya's case goes far beyond sports and highlights problematic understandings about gender identity.

"It relies on folksy ideas about who's really a woman and what traits make you a woman," Karkazis said.

Gender identity exists on a continuum. According to The Beyond the Spectrum Campaign, a group aimed at raising awareness about the LGBTQ community and enforcing laws relating to gender identity and sexual orientation, there are many gender expressions humans will inhabit. On one end of the range is cisgender, a person whose gender identity aligns with the biological sex they were designated at birth. A bigender person, on the other hand, identifies with both genders and/or has a tendency to move between what are deemed masculine and feminine behaviors.

Gender fluid refers to someone whose gender is not fixed and fluctuates between having a gender and not having a gender or identifying with more than one gender. Gender-fluid individuals often reject gender-specific pronouns and prefer to be referred to as “they” or “them." A pangender person prefers not to be identified as one gender, as they relate to many or all gender affinities and expressions, often at the same time. Writer and musician Chaz Bono, actress and LGBTQ+ advocate Laverne Cox, author Janet Mock, and Olympian Caitlyn Jenner are all well-known transgender people. When it comes to gender, it is the individual who can best determine their true identity.

Ultimately, the best way to distinguish between sex and gender is to remember that the former is biological and the latter is more personal. With greater understanding and acceptance of various gender expressions and sexual classifications, language and societal attitudes will eventually catch up.