Children who identify as the gender matching their sex at birth tend to gravitate toward the toys, clothing and friendships stereotypically associated with that gender.

Transgender children do the same with the gender they identify as, regardless of how long they have actually lived as a member of that gender. New findings from the largest study of socially-transitioned transgender children in the world, conducted by researchers at the ������Ƶ, show that gender identity and gender-typed preferences manifest similarly in both cis- and transgender children, even those who recently transitioned.

The , published Nov. 18 in the Proceedings of the National Academy of Sciences, followed more than 300 transgender children from across the United States, as well as nearly 200 of their cisgender siblings and about 300 unrelated cisgender children as a control group. It is the first study to report on all of the participants in the , launched in 2013 by UW professor of psychology .

The transgender children in this study, all of whom enrolled between the ages of 3 and 12, had socially — but not medically — transitioned when they participated: They had changed their pronouns and often their first names, as well as dress and play in ways associated with a gender other than their sex at birth.

For this study, researchers met individually with participants and their parents at participants’ homes, conferences and camps. Participants were asked about specific aspects of life that are typically connected to gender — clothing, toys and friends. The researchers also evaluated participants’ sense of their own gender identity. While the team observed some variability in how strong children’s preferences and identities were, the transgender children showed, on average, strong preferences and behaviors associated with their current gender, just as the cisgender children with whom they were compared.

“Trans kids are showing strong identities and preferences that are different from their assigned sex,” said lead author , who did the work as a postdoctoral researcher at the UW and will start a new position this winter as an assistant professor at Fordham University. “There is almost no difference between these trans- and cisgender kids of the same gender identity — both in how, and the extent to which, they identify with their gender or express that gender.”

In the study, this was evident in assessments of participants’ behavior. “While in both groups there were, for example, some tomboys, on average, most transgender girls, like their cisgender counterparts, wore stereotypically feminine clothing, chose toys such as dolls to play with, preferred playing with female playmates, and identified themselves clearly as girls, and not boys,” said Olson, the study’s senior author. ”Thus the transgender group looked similar to the cisgender group in both the range of responses and the most common responses.”

Of the transgender and cisgender control group participants, about one-third were boys, and two-thirds were girls; the average age was 8. Among the cisgender siblings, the average age was also 8, with slightly more boys than girls.

The finding that transgender children’s gender identity was generally equivalent to that of cisgender children was based on analysis of the survey and behavioral data.

When asked to identify their gender, an equivalent percentage of cisgender and transgender children — 83% and 84%, respectively — named their current gender. (Researchers note that among the youngest participants in all groups, this question often resulted in a less definitive answer like “I don’t know.”)

The similarities among transgender and cisgender children on the various measures were somewhat surprising, researchers said, because transgender children, unlike their cisgender counterparts, were early in life treated as a gender other than the one they currently identify as.

As part of the study, researchers asked parents for photos of their child from birth through toddlerhood at typical social events such as birthdays and holidays to capture information such as what the child wore or what their room looked like. These images helped show that transgender children were initially socialized among families and friends as the gender associated with their sex at birth. However, years later there appears to be no impact of that early sex-specific socialization. These results suggest that years later, the impact of this early sex-specific socialization is not apparent on these measures of children’s gender preferences and identities.

This suggests that transgender children may be self-socializing to learn how to “be” their current gender, Gülgöz said.

“Kids aren’t passive about their environment. Once they have a sense of their gender identity, they will look for cues from their environment, noticing what society’s expectations are, and attending to information about the gender they identify as,” Gülgöz said.

How — and for how long — a transgender child was treated as their assigned sex does not appear to affect their current gender identity and expression, Gülgöz said.

“We’re not seeing any increases or decreases over time in how strongly transgender children identify with their current gender,” Gülgöz said.

This study did not include children who use nonbinary pronouns like “they” or who came out as transgender later in life. Further, all members of the study had at least some family support of their transgender identity. Whether the present findings would extend to these other groups of participants is currently unknown, Olson cautions.

This study adds to findings from previous UW research, which showed that transgender children’s sense of gender identity was consistent, whether tested before or after they transitioned socially.

“Our data thus far suggest that the act of transitioning probably isn’t affecting gender identity one way or the other,” Olson said.

The study was funded by the National Science Foundation, the National Institute of Child Health and Human Development and the Arcus Foundation. Co-authors were Jessica Glazier, Elizabeth Enright, Daniel Alonso, Lily Durwood, Riley Lowe and Chonghui Ji of the UW Department of Psychology; Jeffrey Heer of the UW’s Paul G. Allen School of Computer Science and Engineering; Anne Fast of Western Washington University; and Carol Lynn Martin of Arizona State University.

For more information, contact Gülgöz at sgulgoz@uw.edu.

Grant numbers: BCS-1715068, BCS-1523632, SMA-1837857, HD092347

Unsure what to do, Mack went in search of answers. She found little information online, her pediatrician knew nothing about transgender children, and even a psychologist who specialized in child identity issues couldn’t answer her questions. Mack quickly learned there was almost no research that could help her determine whether to allow her son to live as a girl, or tell her what might happen if she did.

“It’s like stepping into the abyss,” said Mack, who uses a pseudonym to protect her child’s identity. “There are almost no resources out there.”

A new study by , a ������Ƶ assistant professor of psychology, aims to provide insight that could help parents like Mack. The study’s initial results, which are being published soon in , involved 32 transgender children ages 5 to 12 from around the U.S. who are living as their identified gender in all aspects of their lives and in supportive environments.

The paper, believed to be the first ever to focus on this group of children, is intended to launch the first large-scale, nationwide, longitudinal study of transgender children in the United States. Its co-authors are Nicholas Eaton at Stony Brook University and Aidan Key of , a Seattle organization that provides training and runs support groups for families of gender-nonconforming children.

The research is part of the broader , an initiative based out of the UW’s Social Cognitive Development Lab that seeks to engage collaborators nationwide to better understand gender development in gender-nonconforming youth. Mack’s child is participating in the research, and Olson ultimately hopes to recruit more than 100 children; families can sign up through the project’s .

Olson embarked on the project a year ago, partly out of her interest in how children think about social groups, but also because she’d witnessed the challenges of a close friend with a transgender child.

“Seeing how little scientific information there was, basically nothing for parents, was hard to watch,” Olson said. “Doctors were saying, ‘We just don’t know,’ so the parents have to make these really big decisions: Should I let my kid go to school as a girl, or should I make my kid go to school as a boy? Should he be in therapy to try to change what he says he is, or should he be supported?”

Olson’s study sought to determine how deeply held a participant’s gender identity was, or whether transgender children were, as others have suggested, confused or simply pretending to be the opposite gender. The research combined the children’s own self-reporting about gender with tests that assessed the speed at which they associated with various concepts of male and female.

The study found that participants’ responses were indistinguishable from those of two control groups, suggesting that “this identity is a deeply held one.”

The findings are likely to be controversial. The notion that prepubescent children can be legitimately transgender has been met with skepticism in the public realm. And some experts believe the best approach for gender-variant children is not to allow them to live as the “opposite” gender, but to instead try to help them be comfortable with their biological gender.

But growing numbers of doctors, parents and mental health professionals are advocating that children be permitted to live as their identified gender. The attitude shift is motivated at least in part by the often tragic outcomes for transgender people. Forty-one percent of transgender people attempt , compared with 1.6 percent among the general population, and transgender adults face staggeringly of unemployment, poverty, discrimination and homelessness.

The risks to transgender children were driven starkly home by the Dec. 28 of Ohio transgender teen Leelah Alcorn. The 17-year-old committed suicide after posting an online letter saying her conservative Christian parents isolated her and refused to allow her to transition from male to female.

Key, who helped to develop questions and assisted with recruitment for Olson’s study, said he’s met parents of transgender children as young as 5 years old who have significant anxiety and depression, even suicidal impulses.

“Families are searching for information,” he said. “Nobody wants a child to say, ‘I wish I were dead’ when they’re 6 years old.”

Key said previous research and treatment have been hampered by a fear that allowing children to transition to their expressed gender will track them into becoming transgender adults. Rather than forcing children to live as their assigned gender, Key said, allowing simple measures such as using a different name or altering their hair makes them feel validated and supported.

“Then if that child were to change their mind, they would just change back,” he said.

Key expects Olson’s research will affirm what parents he works with have discovered — that embracing their children’s identities leads to happier, healthier young adults.

“The evidence is there in the lives of their children,” he said. “The research is struggling to catch up. That’s why Kristina’s work is so powerful.”

Olson hopes to follow the children in her initial study into adulthood to observe how the support they have received influences their development and whether it translates into more positive outcomes than in today’s transgender adults.

“We have absolutely no idea what their lives will look like, because there are very few transgender adults today who lived as young kids expressing their gender identity,” Olson said. “That’s all the more reason why this particular generation is important to study. They’re the pioneers.”

Mack started a podcast, , and a to chronicle her experiences with her daughter and share information with other parents. She hopes Olson’s work will ultimately help parents like her determine how likely their children are to remain fixed in their gender identities.

“That’s the 64-million-dollar question,” she said. “That’s what everybody wants to know.”