Gender identity disorder research: Q & A with Kenneth Zucker

As a follow up to the recent broadcasts by NPR and several posts regarding gender identity, here is a Q & A involving J. Michael Bailey and Ken Zucker recently posted on the SEXNET email list. Dr. Zucker is the Head of the Gender Identity Service, Child, Youth, and Family Program and Psychologist-in-Chief at the Centre for Addiction and Mental Health in Toronto, Ontario, Canada. Dr. Zucker is the chair of the newly appointed Sexual and Gender Identity Disorders working group for the 5th edition of American Psychiatric Association’s Diagnostic and Statistical Manual (DSM-V). Dr. Bailey is Professor of Psychology at Northwestern University, prolific sexual orientation researcher and moderator of the SEXNET list. As the NPR article noted, Dr. Zucker has extensive clinical and research experience with persons who experience gender dysphoria. This interview was conducted by Dr. Michael Bailey via email and has been slightly edited for posting here. Both Drs. Bailey and Zucker have reviewed and approved it.

Bailey: Both NPR shows used the phrase “a girl trapped in men’s bodies.” How common is this concern over body image?
Zucker: I would say that, in general, there has not been a lot of good empirical research on body image issues in pre-pubertal children with GID. In adolescence, the Dutch group has reported clear evidence of body image dissatisfaction as one finds in adults. One of my PhD students has a dissertation that should be defended later this year in which we studied body image in boys with GID compared to clinical and community controls. We did detect significant body image differences among the three groups: body image in general and in relation to gender-specific anatomic dysphoria. The boys with GID had a poorer body image in general and, of course, with regard to gender-specific anatomic dysphoria. It is only a first pass at this issue and I will report on this down the road after the dissertation is defended.
Bailey: The case on the second NPR show is of a child (natal boy) who had extreme temper tantrums when not allowed to engage in feminine behaviors. Is this common in the kids you see, or is there something unusual about these kids?
Zucker: This is not uncommon. Some parents will report that if they try to limit cross-dressing that this can be very distressing for the boys. Some parents describe it as “he needs his fix.”
Bailey: You are more familiar than anyone else I know with the difference between the British and Dutch treatment centers that yielded the findings that only 20% of the British kids but 100% of the Dutch kids pursued sex reassignment eventually. Did the Dutch center focus on older children (who were less likely to change their minds)? To the extent that the samples were comparable, it is a shocking difference in outcome.
Zucker: I don’t think the British group has published their data yet. But, yes, the Dutch group data are on adolescents and I think that the British group is talking about clients first seen in childhood, not adolescents. The Dutch group now has a paper that is close to being “in press” on their first follow-up of GID children and then followed up later. The GID persistence rate for their boys was about 20% and the persistence rate for girls was 50%. Their persistence rate for boys appears to be similar to what I have summarized for the boys seen in my clinic (Zucker, 2005), but higher than the 12% rate for girls that we published earlier this year (Drummond et al., 2008). The Dutch group speculates that their girls were, at initial presentation, more extreme in their cross-gender behavior than the girls that we reported on, but that will require more careful analysis.
Bailey: The NPR show, and some people on it, kept implying that some of these kids are “really” transgender, and others are not. I suspect you don’t agree with this way of thinking about it, although you recognize that some kids are more likely to become transgender adolescents and adults than other kids are. Can you remind us which factors are associated with persistence of GID from childhood?
Zucker: I don’t think we know yet. Two possible candidates are age at initial evaluation (later age associated with greater persistence rates) and quantitative metrics of cross-gender behavior in childhood.

By persistence rate, Dr. Zucker is referring to the percentage of GID children who are still GID at a later assessment. In the Dutch group, as well as in Dr. Zucker’s research sample, most boys who want to be girls in childhood, end up as men who do not want to be women. For women in the Dutch sample, half remain GID. I think the assessments of low persistence of GID provide some helpful information to parents who wonder about puberty delay and behavioral interventions with their GID children.
Thanks to Drs. Bailey and Zucker for permission to post this conversation.