Last December, Pope Benedict XVI caused great controversy when he gave an address stating that homosexuality and modern theories of gender were as great a threat to mankind as the destruction of the rainforests. I would like to talk about the comments on gender. He said that it is not “out-of-date metaphysics” to “speak of human nature as ‘man’ or woman'” and appealed to the “language of creation”. I’m presuming that the Pope is in part referring to the common assumption that, biologically speaking, the differences between the sexes are clear cut and binary. It turns out that this assumption is completely wrong and biological sex is much more complex than that.
When a child is born, the adults will look at the child’s genitals to identify its sex. These external physical characteristics present an easy and immediate way to categorise the sex of an individual. We see it as an ‘either/or’ situation when in reality there are options inbetween. There may be a large clitoris or a small penis. The genitals may appear ambiguous and could be either a large clitoris with partially fused labia or a small penis which is open along the midline (hypospadic) and empty scrotum.
Most people when thinking of biological sex will refer to chromosomes. We are all familiar of the idea of XX chromosomes denoting the female and XY denoting the male. However, there is a whole range of variations which occur besides these. A female with XO chromosomes (Turner syndrome) typically has non-functioning ovaries and thus no fertility and no menstruation. She may also have a short stature, a broad chest, a low hairline or other features. Females with XXX chromosome often manifest no physical irregularities or medical conditions as only one X chromosome functions at any one time. However, some females with XXX chromosomes may have irregular menstrual cycles and some increased risk of learning disabilities or delayed development of speech or motor skills. A male may have XXY chromosomes (Klinefelter’s syndrome). This is the most common of the sex chromosome irregularities and the second most common condition arising from an extra chromosome. A male with XXY chromosomes may have reduced fertility, some language learning impairment is possible or the increased presence of breast tissue (gynecomastia). Their build and appearance may be lanky and youthful or rounded with some breast tissue. Finally, a male may have XYY chromosomes. This often results in no particularly unusual features or medical problems but individuals can experience an increased growth velocity during their early childhood and become on average seven centimetres taller than their expected final height.
Another important factor contributing to the sex of an individual is the various hormonal processes which take place during development. There can be discrepancies between the sex dictated by the chromosomes and the enviroment created by the hormones. Individuals with XX chromosomes may have adrenal glands producing abnormally high levels of virilising hormones (Congenital adrenal hyperplasia). This can result in a large clitoris or a male appearance. The drug progestin used in the 1950’s and 1960’s affected developing females so that while having functional ovaries they often develop male secondary characteristics (e.g. facial hair) and large clitorises. Congenital adrenal hyperplasia can also occur for males with XY chromosomes but inhibits virilisation in this case. In Androgen insensitivity syndrome, an individual may have XY chromosomes but is unable to metabolise androgens to varying degrees. An individual with complete androgen insensitivity syndrome will have a vagina but no uterus, cervix or ovaries and instead has undescended or partially descended testes. In the case of partial androgen insensitivity, an individual may appear ambiguous with a large clitoris or a small penis and possibly undescended testes. An XY individual with persistant Müllerian Duct syndrome has a male body but an internal uterus and fallopian tubes because Müllerian inhibitors were not produced during fetal development. There are many more variations besides these.
As we can see, sex and gender are complicated even when we ignore the sociological issues and just look at biological factors. There are many variations and ways that humans can manifest in regards to sex and gender. Biological sex is a combination of genital appearance, chromosomes and hormones. Whereas previously the medical establishment would carry out medical procedures to try and normalise the anatomy and appearance of individuals born with ambiguous genitals, there is a growing intersex movement which argues that individuals should be left unaltered and allowed to decide for themselves if they wish to indentify as a particular gender or as intersex. Looking at the evidence, it would appear that having a non-binary concept of gender is not the end of the world and that variations in sex and gender are, in fact, pretty commonplace in nature including within the human species.
This post has been created mostly with information readily available on wikipedia on the topics of intersexuality and other related areas. If you want to learn more about personal experiences and perspectives on being intersex, you might wish to visit the UK Intersex Association or watch the award winning film ‘XXY‘ released in 2007.