Nature, Nurture or Both? Part I: The Nature of Gender

Sociology and Psychology

Photograph: John Lau

At the epicentre of the 21st century’s ‘culture wars’ rests the issues of biological sex and gender identity, which have kicked up maelstroms of heated debate over the traditional binary model of gender and non-binary people at large. For those who believe that sex is equivalent to gender –– thereby often negating the validity of the transgender or non-binary community –– a person is defined by their chromosomes in an entirely binary fashion; in other words, there exists no room for variation. On the other hand, there are those who claim that gender, like sex, lies on a spectrum determined by social factors rather than biology. What, then, is the relationship between sex and gender? Are we shaped by nature, nurture, or both in this regard? If it is either or the two at once, what implications would this hold?

Let us begin by clearly distinguishing sex from gender. While the two terms are often used interchangeably, they are in no way identical. Sex is a label assigned at birth based on biological features such as hormones, chromosomes, and genitalia. While the vast majority of people are typically categorised as either male or female, deviations from the more common XX and XY chromosomal combinations result in the presence of intersex people, who may, for instance, possess female chromosomes and ovaries as well as male external genitalia. Studies have revealed that the rates of intersex births may be as high as 2%; clearly, these are not singular, one-off cases –– they are instead a reflection of the diverse variety of biological sexes that go far beyond the conventionally accepted male-female binary. It is necessary to clarify that sexuality is not the same as biological sex; rather, it refers to a person’s sexual orientation and has little relevance to the sex and gender debate.

What, then, is gender? Considering that biological sex is on a spectrum –– as most things are, according to science –– accepting that gender identity may well be just as complex and varied seems perfectly logical. The real conundrum is this: whether gender is up to nature, nurture, or both at once. Social norms and expectations are undoubtedly instrumental in shaping the people we grow up to become, but it would be unwise to completely disregard biological factors that may be relevant to gender identity.

Most research suggests that prenatal hormones such as testosterone (typically associated with aggression and competitiveness in men) play a major role in setting the scene for a cisgender man’s gender identity, indicating that, one way or another, biology contributes to socialisation. Conversely, other studies have shown that socialisation affects biology in that certain activities geared towards aggression and competition may cause cisgender men to experience decreased or ‘dampened’ levels of testosterone. Such a revelation begs the question: does this contradict previous research on hormones and their influence on identity? Or is it all merely a snapshot of the nuance involved in the psychology of gender?

In early 2019, a study was published in The Journal of Clinical Endocrinology & Metabolism on the genetic correlation between gender dysphoria and sex hormone signalling. It concluded that ‘gender dysphoria has a polygenic basis’, meaning that the condition is rooted in the expression of several genes –– something innate, intrinsic, and somehow embedded in our DNA. It further noted that ‘[while] genetics plays a role, it is not the sole determinant of gender identity’. The implications of this are manifold and extensive, suggesting that we may each be hardwired towards a certain gender thanks to biological factors: that our struggles or lack thereof when it comes to identifying ourselves may well be down to our genetic makeup, and that the argument against claiming a gender that usurps the traditional male-female binary as being contrary to ‘nature’ is moot.