Libido Lines
- Thomas Allen
- Feb 18, 2022
- 6 min read
A single looping line and three dots have changed the way I think about spectrums.
Each sexy drawing in this series of ‘Libido Lines’ comprises an individual loop – a line that finishes back where it started – and three dots. The range of forms is created simply by twisting and pulling the loop and moving the dots around.
Particularly interesting is just how minor a tweak is required sometimes to transform male into female anatomy; a slightly more exaggerated arc here and a dot shifted there, et voilà, the leap is made from Venus to Mars!
Lines 34, 35 and 36 from the Libido Lines series: a few small tweaks and a masculine form becomes feminine
This fluidity of form got me wondering whether biological sex is a spectrum. Gender clearly is, since it’s a social construct, but what about the mechanics of a human organism’s sex?
Well, the first place to start is usually ‘downstairs’ – the genitals can be a pretty good giveaway and are a doctor’s first port of call when identifying a new-born child’s sex. This won’t always give the doctor a clear-cut answer, though, because genitals do vary and can range between penis and vagina. In fact, it has been estimated by Anne Fausto-Sterling, professor of biology and gender studies at Brown University, that 1.7% of the human population is born intersex1 – which makes it about as common as being born with red hair. (We’ll be returning to this figure later.)
What about genes then – do they give a clearer answer? Well, some of those intersex conditions are sex chromosome anomalies without any visible traits. While females typically have XX chromosomes and males usually have XY chromosomes, some people are born with alternative chromosomal makeups. For instance, those with Turner Syndrome have a single X, while those with Klinefelter Syndrome have XXY2. There are even cases where an individual can be composed of cells with different genetics: Chimaerism, for example, occurs when two fertilised eggs merge in the womb and develop into a single child3. So, genetics aren’t so black-and-white either.
Genes – along with hormones – largely determine what happens to a person’s body during sexual differentiation, which is the ongoing process by which a person develops the physiological characteristics associated with either sex.
At this point, the line between male and female becomes even more blurred, as we take into consideration other observable traits – the ‘phenotype’, if you like a bit of scientific terminology. Hip and shoulder width, breast size, pitch of voice, distribution of fat deposits, height, body hair, and so on: there’s such diversity in the population, with significant overlap between men and women.
Taking height as an example, if we were to measure a representative group of people and plot the heights of the men and women separately on a graph, we would get two overlapping normal distributions, with a lower average height for women than for men (See graph below)4. The point is, while men are generally taller, not all men are taller than all women. It’s not binary.
Overlapping distributions for secondary sexual characteristics, such as height
Doing the same with other traits, from hip width to pitch of voice, we would find that there are sets of characteristics that are statistically more likely to be attributed to either males or females, without being mutually exclusive.
At this point, it’s really starting to look as though biological sex is indeed a spectrum, with certain attributes clustering, statistically, around males and females, and an arbitrary line being drawn between the two. But hold your horses because we haven’t looked at gonads and gametes yet.
Gonads are our primary sex organs: testes in males and ovaries in females, producing sperm and eggs respectively, which are the sex cells known as gametes. Most organisms – including us humans – produce distinct types of gametes that must be combined for sexual reproduction. Since there are no intermediate gametes, this is a criterion by which sex can be defined as a binary system rather than a spectrum.
Evolutionary biologist Colin Wright makes this argument in his article Sex is not a spectrum5, emphasising that an individual’s inability to actually produce gametes – due to infertility issues or being prepubescent, for instance – is irrelevant so long as the gonads are present, which is more than 99.98% of the time.
The remaining 0.02% (or more precisely, 0.018%) are intersex. This figure differs from Fausto-Sterling’s previously mentioned figure of 1.7% because Wright narrows the definition of intersex, distinguishing between ‘differences of sexual development’ (DSDs) and ‘intersex’6.
Wright goes on to say that “just because sex may be ambiguous for some does not mean it’s ambiguous… for all.”
Taking the example of flipping a coin – specifically a nickel for this statistic, since Wright is American – he points out that the coin will land on its edge 0.0166% of the time7 – strikingly similar to the probability of being born intersex.
“Almost every coin flip will be either heads or tails,” says Wright, “and those heads and tails do not come in degrees or mixtures.” They are discrete outcomes, regardless of edge cases.
Likewise, the vast majority of humans develop either ovaries or testes. Male and female are distinct outcomes, despite the existence of intersex conditions.
This is a sensitive subject, so I feel it’s important to stress that these observations are not intended to marginalise people who are born intersex or with DSDs. The low prevalence of any condition in the population is certainly no grounds for mistreatment or disrespect.
In fact, while interpreting sex as a spectrum might initially seem to be liberating, on closer inspection it appears to inadvertently promote sexist ideals and stereotypes.
Returning to the idea of overlapping distributions that plot secondary sexual characteristics on a graph, biological sex is being quantified, meaning that a person’s male-ness or female-ness could be measured in relation to that of others.
Defining sex as a spectrum inadvertently promotes sexist stereotyping by suggesting a person is more male if they are taller and more female if they are shorter, for example
Wright points out that this can lead to the argument that person B on the graph above is more female than person A just because they have larger breasts or are shorter in height, or that person D is more male than person C simply by virtue of their wider shoulders or deeper voice.
“For decades,” says Wright, “we’ve properly taught our children that this kind of logic is insulting and toxic – that a girl with more masculine features is just as much a girl as her friend with a more stereotypically feminine physique.”
So, the overlapping distributions are not so much a measure of male-ness and female-ness as a measure of masculinity and femininity based on physical attributes, and they’re a very simplistic measure at that. This one-dimensional diagram only measures a single variable – height in my example. It could be taken into the third dimension by introducing a z-axis to paint a more interesting picture, but even so, only two characteristics would be taken into account. What about measuring, say, ten characteristics? I don’t know how – or even if – that could be depicted graphically.
I came up against this limitation when considering how my Libido Lines series might be displayed. At first, I imagined the drawings arranged in a row that transitioned from vagina on one side to penis on the other, with a gradation between the two. However, when I tried doing this, it soon became apparent that the spectrum isn’t linear; the drawings instead settled into a pattern of loops where lineages of forms branched out, circled back on themselves and converged on one another.
So it is that this series embodies in its meandering layout the slippery complexity of the spectrum between masculinity and femininity, while also reflecting the binary nature of sex with its black-and-white aesthetic.
Thomas Allen, Libido Lines series, India ink on paper
(Hero image: Thomas Allen, Line 7 from Libido Lines series, India ink on paper)
Footnotes
Fausto-Sterling, Anne. Sexing The Body: Gender Politics And The Construction Of Sexuality, Basic Books, 2000
UK National Health Service website, Differences in Sex Development
In the popular YouTube channel SciShow’s episode There are more than two human sexes, presenter Hank Green talks about sex chromosome conditions such as Chimaerism and Mosaicism
The bimodal distribution is sometimes invoked at this point in the discussion, but it’s not actually applicable here. In the case of height, combining the male and female distribution curves in my example will actually produce a unimodal distribution. If you’re interested, this paper explains why: Is Human Height Bimodal?
Colin Wright, 2021, Sex is not a spectrum, Reality’s Last Stand (website)
For Colin Wright’s full break-down of the 1.7% intersex figure, see his 2020 article Intersex is not as common as red hair, Reality’s Last Stand (website). Also see Leonard Sax’s 2002 article How common is intersex? A response to Anne Fausto-Sterling, Journal of Sex Research, 39:3, 174-178
Murray, Daniel B.; Teare, Scott W. (1993) Probability of a tossed coin landing on edge, Physical Review E (Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics), 48:4, 2547-2552
Lines 38, 39 and 40 from the Libido Lines series
Connect on social media
To see the full Libido Lines series:
Comments