All of us are in positions of navigating a social world that is imbued with norms and expectations regarding sex and gender (Butler, 2015). While many people develop gender identities that are congruent with their assigned genders at birth, some people develop gender identities that are different from their assigned genders at birth.
As with all other aspects of people’s characters, people’s gender identities are complex outcomes of multiple factors that interact in dynamic ways throughout development. There is no single causal factor that makes someone trans. Rather, people’s gender identities are formed through complex and dynamic interactions between various social, cultural, biological, and psychological factors (Ashley, 2023; Burri et al., 2011).
Nonetheless, regardless of how it is caused, it is important to recognise that people’s gender identities are authentic parts of their characters. Gender identity is not something that can be forced on someone.
Biologists and philosophers have increasingly come to understand that the concept of “innate” is unsuitable for explaining how complex aspects of our characters develop (Griffiths, 2001; Lehrman, 1953; Maung, 2021; Oyama et al., 2001). All of our behavioural and psychological features are outcomes of complex and dynamic interactions between multiple resources throughout development. These include the ways we are embodied as biological organisms, our interpersonal interactions with others throughout our early lives, the norms and values of the social environments wherein we are embedded, and various contingent features of our personal biographies.
The interactions between the various factors that influence development are complex and context sensitive (Oyama et al., 2001). Hence, there is no single gene or set of genes that determine one’s gender identity, because the effects that any particular gene or set of genes have will vary with what other factors and developmental conditions are present. Indeed, research has shown that the variation in people’s gender identities in the population correlates only weakly with variations in genes, but correlates more strongly with variations in people’s social and material environments (Burri et al., 2011). Furthermore, some people describe gender identity as being like a journey that can change over time, which undermines the view of gender identity as something fixed or genetically predetermined.
The complexity of gender identity development does not imply that being trans is a “choice”. It merely shows that the reasons we turn out the ways we are can be very subtle and cannot be reduced to singular causes. As well as our genes, many of the factors that influence how we develop are beyond our control, such as our early interpersonal interactions and the social environments into which we are born.
The fact that one’s environmental conditions influence how one develops does not imply that one’s identity is a “choice”, a “fad”, or a “phase”. As social beings, almost all our desires are influenced by our interactions and our environments. What is important is not what caused these desires, but whether we endorse these desires as authentic parts of our characters.
The assumption that being trans is either “innate” or a “choice” also rests on a false dichotomy. This gives a misleading impression that one’s authentic gender identity is something passive. However, the richness of gender identity discredits this dichotomy. Gender identity is a rich and nuanced phenomenon that involves one’s active agency, autonomy, and self-determination, as well as one’s first-person knowledge of one’s own experience (Ashley, 2023; Bettcher, 2009; Dembroff, 2019; Jenkins, 2018). Indeed, it is this agential aspect that makes one’s gender identity authentic, insofar as one is endorsing one’s identity as an integral feature of one’s character.
There is some recent research which has suggested that there may be observable differences between the brains of trans people and cis people upon neuroimaging (Ristori et al., 2020). However, caution is warranted regarding how the results of the research are interpreted.
First, the results have not been reliably replicated by other research and are confounded by other factors. For example, there is much more variation in brains within the same gender than across different genders and there is a lot of similarity of brains across genders (Joel, 2011; Rippon, 2019). Hence, rather than there being “male” brains and “female” brains or “cis” brains and “trans” brains, people possess complicated arrays of neurobiological characteristics that cannot be captured with a binary classification system.
Second, even if there are some neurobiological differences in the brains of cis people and trans people, this would not imply that these neurobiological differences are what cause the people to be cis or trans. Rather, it is possible that the neurobiological differences are caused by the different gendered experiences and behaviours of cis people and trans people (Juraska, 1998; Rippon, 2019). We are highly neuroplastic creatures whose brains are continually shaped by various social, cultural, developmental, and biographical factors, and so it’s unsurprising that people with different experiences could have different brains. The neurobiological differences here could be the effects of the different gendered experiences and behaviours, rather than the causes.
Third, the mere presence of a neurobiological difference tells us absolutely nothing about how we ought to treat trans people. Acceptance of gender diversity is an ethical principle concerning basic respect for one another as persons. We don’t require a scientific theory about neurobiology to show that this respect is justified.
It may be tempting to assume that discovering a biological cause of gender identity is required to show that trans identities are “real” and “legitimate”. However, there are reasons why this is an unhelpful assumption. First, given the complexity of gender identity, the likelihood is that it does not have a singular biological cause, but is instead a contingent outcome of complex and dynamic interactions between social, biological, psychological, and biographical factors. Second, respect for the legitimacy of one’s gender identity should not have to be dependent on demonstrating a biological cause.
Acceptance of gender diversity is a moral and ethical principle that is grounded in basic respect for one another as persons who have the rights to determine their own identities. This respect should be taken as foundational, rather than something that needs to be vindicated through scientific research. We don’t require a scientific theory about genetics or neurobiology to show that respect for people’s identities is justified.
Furthermore, in contexts where this basic principle of respect is not present, the search for biological differences between groups of people can be harmful. Not long ago, there was a search for a “gay gene”. Some were claiming that showing homosexuality to have a biological basis would increase acceptance of gay people. However, many others suggested the opposite, as they were worried that finding such a biological basis would enable homophobic genetic screening programs and biological “treatments” for homosexuality to be enforced (Longino, 2013). Ultimately, no “gay gene” was found, but this example shows that demonstrating a biological basis does not necessarily imply increased acceptance. Rather, acceptance of diversity must be taken as a foundational ethical principle, regardless of whether or not there is a biological explanation for the diversity.
And so, instead of trying to find biological reasons for why people are the ways they are, we ought to respect people’s gender identities and take this respect to be a foundational ethical principle. As the philosopher Judith Butler notes:
“All of us … are in the active position of figuring out how to live with and against the constructions—or norms—that help to form us … My sense is that we may not need the language of innateness or genetics to understand that we are all ethically bound to recognize another person’s declared or enacted sense of sex and/or gender”. (Butler, 2015)