I was recently berated by someone telling me that they were surprised that a biologist, who does things like determining the sex of a fly, a fish, or a spider, actually agrees with people who see gender as fluid and variable, and not necessarily in alignment with sex. All I can say is…there are an awful lot of people out there with a seriously mangled version of scientific concepts. Worse, they use their misunderstanding of basic terms to argue that they have a scientific foundation for their bad ideas.
Just to help you out, here’s a succinct definition of some fundamental concepts, as written by an ecologist in the PLOS Ecology Community blogs. Your expectation that biologists share the narrow, bigoted views about sex and gender that you have are probably totally wrong — so you might want to hesitate next time you think it’s a good idea to lecture professional biologists on biology.
The words “sex” and “gender” are often used interchangeably in colloquial contexts, but they have different meanings that are relevant to our work in ecology.
“Sex” refers to categories based on a combination of biological and physical characteristics, such as body organs, chromosomes, and hormones (WHO 2011, APA 2015). Sex is commonly assigned on the basis of external genitalia at birth and is often assumed to be only male or female, but scientists have identified at least five different groupings of human sex chromosomes, anatomy, and hormone physiology (Fausto-Sterling 1993). Other terms that relate to sex include intersex, freemartin, and hermaphrodite. (Note that hermaphrodite is a term currently used for animals but considered outdated and rude when used to describe humans; the preferred contemporary term for humans is intersex.) (“Sex” can also refer to activity among one or more individuals that may or may not result in sexual arousal and/or genetic recombination. I’m not addressing this meaning of the word in this piece.)
“Gender” refers to identities and categories based on social or cultural characteristics (WHO 2011, APA 2015). Gender is both internal (gender identity, which is each person’s innate sense of their own gender), and external (gender expression, which is how each person expresses their gender identity). Woman, man, masculine, and feminine are all terms that can refer to gender. Transgender is a term used to describe a person whose gender identity is different from the sex they were assigned at birth. Gender is primarily a human and social term, and it is not usually relevant for non-human animals or plants.
When we observe biological and physical aspects of our study organisms, those observations tell us about the sex of those individuals, not the gender.
When we interact with other humans, we usually know more about their gender rather than their sex: for example, we often know about their clothing and hairstyles but not very much about their body organs, chromosomes, or hormones. (Furthermore, and this fact may be obvious, but clothing and hairstyles are not necessarily signifiers of any particular gender identity.) Among humans, sex and gender may be related, but they are not equivalent. In other words, female and woman are often thought to be synonymous, but in reality, female refers to different characteristics than woman does.
Also good was this bit:
If you (a) are talking about scientists and (b) interested in categories such as “women” and “men,” it’s more polite to use gender rather than sex categories. Why? In professional contexts, we may think we know what gender our colleagues present themselves as (e.g., women, men), but probably don’t know very much about the biological sex of our colleagues (e.g., chromosomes, body organs, hormones). It’s odd and inappropriate to make assumptions about other people’s bodies, especially in a professional context.
This. When I meet people, I don’t know anything about their sperm count or their chromosome arrangement or even what their genitals look like (you don’t have to show me), so all the sex details are irrelevant to our interactions. Gender matters because we have a huge amount of social capital, some good, some bad, invested in how people present themselves, and also because those gender signifiers are diverse and do a better job of reflecting how people see themselves in society, and how society sees them.
You know, when a population is identified as a discrete binary of two kinds of individuals, male and female, my usual thought is that the next step is to pair up individuals in bottles and do a genetic cross. That’s not how we treat human beings in our communities.




