Sex is determined by genetic make-up, i.e. do you have x-y chromosomes or x-x chromosomes. This is a scientific definition as to whether you are of the male sex or female sex. In some cases, this is incorrectly attributed (including on the birth certificate) due to a misleading presentation of external sexual characteristics at birth.
The identity crisis that is likely to present itself in these cases is well illustrated through fictional works such as The Wasp Factory by Iain Banks and Middlesex by Jeffrey Eugenides. The misattribution of sex at birth is not the fault of the doctors, midwives, or parents who, in good faith (and in the absence of a genetic test), declare the child to be male or female.
In these cases, it is the right thing to do to allow for the change of sex on the birth certificate (if so desired by the person involved) as it was incorrectly assigned at birth.
Gender identity or expression is another matter, and a far more complex one. It cannot be reduced to a scientific observation. At birth, I would argue, the gender identity of a person is not known. It is something that is going to emerge later. Furthermore, it is an identity that one may choose to express on identity documents, on social media, and elsewhere; or, one may wish to keep it private and only make it known to those with whom one has an intimate relationship. There are very few people in my life about whom I need to know as to whether they are gay, lesbian, heterosexual, transgender, or bisexual. Probably only with my sexual partners, and then mainly for clarity!
When it comes to children and marriage we get into a murkier area. For the marriage contract, it is helpful to know the sex of the person you are marrying. Furthermore, if the marriage is to include intimacy and carnal knowledge then, I would argue, both the sex and gender identity matter. However if it is strictly a “business marriage contract”, freely entered for the purpose of sharing of wealth, inheritance rights, social aspirations, etc, then, you could argue gender identity and sex are not essential disclosures for either partner.
For children (of any parents), we enter the realm of competing rights. Does a child have the right to know the sex and gender identity of their genetic parents and their adoptive parents? Or should they have the right to be able to retrieve this information (if it exists) if they so desire?
I would say the answer to this is ‘yes’ on the sex and ‘preferably’ on the gender identity. It helps to know these things about the people who are responsible for your care and well-being; it helps to understand as much as possible about your parents as they will have a significant impact on the formation of your personality, your self esteem and your trust in fellow human beings.
A child has no choice about being conceived and born — this is the responsibility of the parents who conceive that child. At the very core of anyone’s identity has to be an understanding of the genetic heritage that has brought you to life — who isn’t curious about where they came from? Let us suppose the following scenario: A woman and a man bear a child. As mother and father they are both named on the child’s birth certificate. When the child is four, the mother leaves the marriage, moves to another continent and starts gender re-assignment, becoming estranged from her daughter, former husband, and her family in the process. Five years later, all her identity documentation including her birth certificate have been changed to ‘male’. To all concerned she, now a he, is a man. He dies three years later.
In the meantime, the father has got Alzheimer’s dementia and is living in care. Does this child have the right to find out (from their genetic mother’s birth certificate) that their mother did exist genetically as a woman but later adopted the male gender identity? Is the case for changing your sex attribution on your birth certificate similar to the right to be forgotten, and disappeared, even to your children?
A practical solution, from the legislative end, would be to have birth certificates expanded to include two sections: One for the sex (that is filled out as male or female at birth open to correction as outlined above) and a second section for gender identity that starts off blank (or, as LGBTHQ to cover everything) with the option of refinement from the age of 16.
Passports, driving licenses and other identity documents could stick to a male/female attribution to be decided by the individual concerned.
A more nuanced way of thinking about this is to realize that within us all there is both a male and a female energy, and a fluid expression of both.
“Why can’t a man be more like a woman?” is just as valid as “Why can’t a woman be more like a man?”
In Billy Wilder’s film Some Like it Hot, the concluding scene sums it up nicely: Daphne (Jack Lemmon) dramatically reveals the secret of his real sex to Osgood by whipping off his wig and saying “I’m a man!” to which Osgood replies, “Well, nobody’s perfect.”