One of the first conversations I had with Susana was about the impossibility of scientifically defining sex… Let us imagine you were trying to create a system to definitively define sex. There are perhaps four indicators you might use - the physical body, the brain, the hormones, and the chromosomes. Let us say I was assigned the female sex at birth, and have subsequently identified as ‘female’ throughout my life. In terms of the physical body, if I discovered that I did not have ovaries, I would not ‘lose’ my sex. Equally, if, after puberty, I happened to be flat chested, the medical profession would not find it necessary to reassign my sex. If, later in life, I undergo a hysterectomy I will not be considered less ‘female’ by any reasonable person.

Secondly, let us say that I define myself as transgender. A little more than 9 people in every 100,000 define themselves as transgender. That's, by my calculations, 27,690,000 people in the world – more than the population of Australia. The idea of a ‘gendered brain’ has been thoroughly debunked by numerous scientific studies and it would be wrong to diagnose me as mad, mistaken, or suffering from a neurological disease. ‘Male’, ‘female,’ and non-binary brains have the same structure and, crucially, plasticity. Brains reflect the lives of their owners far more than their sex. It’s important to acknowledge here that despite this, the transgender community continue to suffer prejudice and discrimination at the hands of the ignorant.

Thirdly, in terms of hormones, there are many people who identify as ‘female’ – myself included – who have higher levels of testosterone than the average male identifying person, and vice versa. Furthermore, when I go through the menopause and stop producing estrogen, I do not intend to reassign my sex, and I would be rightfully outraged if someone else suggested that I should.

Finally, we come to the chromosomes – considered by many to be the last bastion of binary sex determination. But, yet again, here we find that things are far from clear - the water is muddy and opaque. When Susana and I started In Posse, one of the first things we did was check my chromosomes, and this is why. I could have been born with the opposite chromosomes to my phenotypical sex. This might mean that I had grown up with a penis and testicles, identifying as ‘male,’ but later discovered that I have XX chromosomes (‘XX’ being the genetic marker of what we describe as genetically ‘female’, whilst ‘XY’ is ‘male’). Equally, I could have a womb and ovaries but discover that my chromosomes are, in fact, XY.

So, the question Susana posed to me was… where is sex? If our sex does not reside in the body, the brain, the blood, or the DNA… Where is it? What is it? The scientific process for making In Posse draws on some of the examples above. It is also an attempt to illustrate the questions we are left with when we consider sex; to further contaminate the water and problematize the binary.

- Charlotte Jarvis