Why sex and gender aren’t binary issues

The woman on one side, the man on the other, you’re either a princess or a knight, with nothing in between. And you certainly have no say in the matter, your sex is what you’re born with. Period. People who think like this usually point to one main argument: That’s the science, they say. Biology to be exact.

Yet the broad scientific consensus now looks different: Sex is a spectrum. If you want to stick with the picture, man and woman are at opposite ends, but there’s a lot going on in between. XX chromosomes = female, XY chromosomes = male. This is how sex is formed, we learn in school. Clearly, the sex chromosomes are important, but it’s not quite so simple.

For example, there are people whose physical traits are female, but they carry the “male” sex chromosomes XY in their cells, and vice versa. A gene located on the short arm of the Y chromosome, called SRY, determines (along with other players) whether or not testes will form in an embryo. If, for eg: this gene is not read due to a mutation, or remains silent, so to speak, no testes will develop despite XY chromosomes. On the other hand, testes can grow in people with XX chromosomes if the gene jumps over to the X chromosome (presumably during cell division) and is read.

So how sensible is it to determine sex after birth, as is mostly done at the moment, solely on the basis of externally visible sexual characteristics? Naturally occurring variations in sex chromosomes are many and varied. This can also have an effect on the visible sexual characteristics, the genitals. Individuals who cannot clearly be assigned one of the binary sexes refer to themselves as intersex or inter. The United Nations estimates that 1.7% of the world population belongs to this group. The number is comparable to that of red-haired people in the world. Since 2018, newborns like this can be registered as “diverse” in Germany. Other countries, such as Australia, Bangladesh and India, also recognise a third sex.

Sex can also change over a lifetime, or more precisely the gonadal sex identity can. Chinese researchers found this out in a study on mice. The genes responsible for this change are DMRT1 and FOXL2, which normally balance the development of ovaries and testes in a kind of yin-and-yang relationship. When there was a change in these genes, the gonadal sex phenotype could change even in adult animals.

Testosterone: The male hormone! Estrogens and progesterone: The female hormones! That’s what they teach you in school, but again, it’s not that simple. Men and women as well as gender-diverse individuals all have these sex hormones in their bodies. In children there is no significant difference in sex hormones. It is not until puberty that testosterone levels in particular go up, so that males on average have more testosterone than females.

Today, targeted research is being conducted on the hormonal overlap between the sexes. It has also been discovered that hormone levels depend to a remarkable extent on external factors and are not, as previously assumed, purely genetically predetermined. Expectant fathers, for example, have less testosterone over the period of their partner’s pregnancy. The supposedly female hormones estradiol and progesterone, on the other hand, are produced more when individuals compete for dominance, a behavior that is stereotypically considered masculine. It’s safe to say that there’s no pure binarity of sex characteristics. Any supposedly “biological” arguments in this direction are not in line with the current state of science. Sex and gender are issues as complex and versatile as the humans (and mice and other animals) who carry them.

This article was provided by Deutsche Welle