Authorship: This project was created by Claire Lavergne, a Master’s student in Human Paleobiology at the George Washington University [graduated May 2023], under the mentorship of Dr. Agustín Fuentes [Princeton University] and supervision of Dr. Briana Pobiner [Smithsonian National Museum of Natural History].
Despite what pop culture may tell you, men and women are both, in fact, from planet Earth.
Backing up a bit, let’s explain what we mean by gender and sex.
Gender and sex are different, but deeply intertwined.
Gender is the “culturally contextualized social and structural experiences as well as expressions of identity” (DuBois & Shattuck-Heidorn, 2021). All humans have the same biologies, but different cultures have historically had different genders with different roles. For instance, the Bugis people of Indonesia recognize five genders (Davies, 2007), some of them similar to what we in the West would consider transgender, i.e., being of a gender different from our sex. Among the Chambri of Papua New Guinea, while women have the biology to give birth, they are also the primary providers of the family, though men occupy equally important positions in society. In this culture, it does not seem that women are expected to be submissive to men, or vice versa (Errington & Gewertz, 1987). These are just two examples of many more.
Sex is defined as the “biological characteristics generally related to reproductive anatomy or physiology” (DuBois & Shattuck-Heidorn, 2021). The terms male and female are used to classify trends within biology that follows the 3G sex model: genetic-gonads-genitalia. Female refers to having XX chromosomes-ovaries-vagina & related internal and external reproductive organs. Male refers to having XY chromosomes, testes, and the penis. Other components of biological sex are usually consistent with the genetics-gonads-genitalia triad but variation exists. While this triad is internally consistent in 99% of people, those for whom it is not are considered intersex (DuBois & Shattuck-Heidorn, 2021; Joel, 2014).
The aim of this project is to break down what “biological sex” is without reducing its many facets to unhelpful binaries. These generalizations can be useful to simplify the complicated nature of, well, nature, but they aren’t always accurate. That being said, for ease of access, this project will break sex down into the following categories: genes & chromosomes, hormones, gonads & genitalia, the skeleton, secondary sex characteristics, and the brain.
NB: While the term “hermaphroditism” has long been used in biological and medical literature, this project will use the term “intersex” instead, in deference to intersex advocates.
Categories of sex biology:
Is biological sex in your DNA?
How does your reproductive system relate to your sex biology?
Can we determine someone’s sex based on their skeleton?
What are secondary sexual characteristics?
[Last updated: May 29th 2023]