Maddalena Marini, Ph.D.

The Hidden Mind


Gender Development

Neither sex assignment at birth or social gender norms define gender expression.

Posted Feb 04, 2020

Research provides evidence that cisgender children (children who identify as a boy or a girl according to their assigned sex at birth) show clear patterns of gender development. By age three, they label their gender based on their sex assignment at birth and prefer children of the same gender as playmates. Throughout early and middle childhood, cisgender children show behaviors that are stereotypically associated with their gender, including preferences for specific toys and clothes.

But what about transgender children (children who live as a gender that differs from their sex assignment at birth)? Transgender children have a completely different gender socialization experience, compared to their cisgender peers. They live a part of their childhood as members of one gender (i.e., the gender associated with their assigned sex at birth) and the other part as members of another gender (i.e., the gender with which they identify). What does their gender development look like? Does it differ from cisgender children’s gender development? Is it influenced by the amount of time in which they have been treated as their current gender?

A recent study published in Proceedings of National Academy of Sciences investigated these important questions in a large sample of 317 transgender children aged from three to 12-years-old. To this end, Gülgӧz and colleagues focused on transgender children’s gender identity — i.e., the internal sense of being a boy or a girl - and their gender expression — i.e., the behaviors and preferences that are highly stereotypical of their current gender.

Gender identity was assessed both at the explicit and implicit levels. Implicit gender identity was measured using an Implicit Association Test (IAT) evaluating the association strength between the concepts “Me” and “Not me” and the categories “Girls” and “Boys.” The IAT is a computer-based time-reaction task that is thought to assess automatic mental associations and representations that are encoded in memory and that occur outside of people’s awareness and control. Explicit gender identity was measured by using a self-reported item asking children whether they felt to be a boy or a girl. 

Gender expression, instead, was measured only at the explicit level. That is, children were presented with questions about toy, peer, and clothing preferences and asked to verbally say their answers or point out them on a computer or a response sheet. For example, to determine toy preferences, children were asked to indicate the toy that they would like to play with the most among a series of toys ranging from stereotypically “boys” toys to stereotypically “girls” toys. 

Results showed that transgender children identified as members of their current gender group than their assigned sex at birth, both at the implicit and explicit level and reported preferences that were stereotypically associated with it. In other words, transgender boys identified as boys and preferred stereotypically masculine toys and clothes as well as being friends with other boys. Similarly, transgender girls identified as girls and favored stereotypically feminine toys and clothes, and playmates of the same gender.

Notably, Gülgӧz and colleagues showed also that transgender children’s gender identity and expression were not related to the amount of time in which they were treated as their current gender, i.e. when they had socially transitioned, and do not differ from gender development of their cisgender peers. That is, both transgender and cisgender children report to identify with their current gender and showed similar stereotypical gender-typed preferences. 

Gülgӧz and colleagues claim that these results “provide preliminary evidence that neither sex assignment at birth nor direct or indirect sex-specific socialization and expectations in alignment with early assignment necessary define how a child later identifies or expresses their gender”. In other words, “early sex assignment and parental rearing based on that sex assignment do not always define how a child identifies or expresses gender later.”


Gülgöz, S., Glazier, J.J., Enright, E.A., Alonso, D.J., Durwood, L.J., Fast, A.A., Lowe, R., Ji, C., Heer, J., Martin C.L., & Olson K.R. (2019). Similarity in transgender and cisgender children's gender development. Proceedings of National Academy of Sciences, 116(49):24480-24485.