Evidence against a typology: a taxometric analysis of the sexuality of male-to-female transsexuals

Dimensions over categories: a meta-analysis of taxometric research

Taxometric procedures have been used extensively to investigate whether individual differences in personality and psychopathology are latently dimensional or categorical ('taxonic'). We report the first meta-analysis of taxometric research, examining 317 findings drawn from 183 articles that employed an index of the comparative fit of observed data to dimensional and taxonic data simulations. Findings supporting dimensional models outnumbered those supporting taxonic models five to one. There were systematic differences among 17 construct domains in support for the two models, but psychopathology was no more likely to generate taxonic findings than normal variation (i.e. individual differences in personality, response styles, gender, and sexuality). No content domain showed aggregate support for the taxonic model. Six variables - alcohol use disorder, intermittent explosive disorder, problem gambling, autism, suicide risk, and pedophilia - emerged as the most plausible taxon candidates based on a preponderance of independently replicated findings. We also compared the 317 meta-analyzed findings to 185 additional taxometric findings from 96 articles that did not employ the comparative fit index. Studies that used the index were 4.88 times more likely to generate dimensional findings than those that did not after controlling for construct domain, implying that many taxonic findings obtained before the popularization of simulation-based techniques are spurious. The meta-analytic findings support the conclusion that the great majority of psychological differences between people are latently continuous, and that psychopathology is no exception.

Expanding Statistical Frontiers in Sexual Science: Taxometric, Invariance, and Equivalence Testing

Sexual scientists must choose from among myriad methodological and analytical approaches when investigating their research questions. How can scholars learn whether sexualities are discrete or continuous? How is sexuality constructed? And to what extent are sexuality-related groups similar to or different from one another? Though commonplace, quantitative attempts at addressing these research questions require users to possess an increasingly deep repertoire of statistical knowledge and programming skills. Recently developed open-source software offers powerful yet accessible capacity to researchers wishing to perform strong quantitative tests. Taking advantage of these new statistical opportunities will require sexual scientists to become familiar with new analyses, including taxometric analysis, tests of measurement variability and differential item functioning, and equivalence testing. In the current article, I discuss each of these analyses, providing conceptual and historical overviews. I also address common misunderstandings for each analysis that may discourage researchers from implementing them. Finally, I describe current best practices when using each analysis, providing reproducible coding examples and interpretations along the way, in an attempt to reduce barriers to the uptake of these analyses. By aspiring to explore these new statistical frontiers in sexual science, sexuality researchers will be better positioned to test their substantive theories of interest.

Autogynephilia and the Typology of Male-to-Female Transsexualism

Abstract. Sexual scientists have recognized for over a century that biologic males who seek sex reassignment – male-to-female (MtF) transsexuals – are not a homogeneous clinical population but comprise two or more distinct subtypes with different symptoms and developmental trajectories. The most widely used typologies of MtF transsexualism have been based on sexual orientation and have distinguished between persons who are androphilic (exclusively sexually attracted to males) and those who are nonandrophilic (sexually attracted to females, both males and females, or neither gender). In 1989, psychologist Ray Blanchard proposed that most nonandrophilic MtF transsexuals display a paraphilic sexual orientation called autogynephilia, defined as the propensity to be sexually aroused by the thought or image of oneself as a woman. Studies conducted by Blanchard and colleagues provided empirical support for this proposal, leading to the hypothesis that almost all nonandrophilic MtF transsexuals are autogynephilic, whereas almost all androphilic MtF transsexuals are not. Blanchard’s ideas received increased attention in 2003 after they were discussed in a book by psychologist J. Michael Bailey. The concept of autogynephilia subsequently became intensely controversial among researchers, clinicians, and MtF transsexuals themselves, causing widespread repercussions. This article reviews the theory of autogynephilia, the evidence supporting it, the objections raised by its critics, and the implications of the resulting controversy for research and clinical care.

Sexual orientation of trans adults is not linked to outcome of transition-related health care, but worth asking

Since the beginning of contemporary transition-related care at the outset of the 20th century, sexual orientation has ben considered to be closely connected with gender identity and the developmental trajectories of trans people. Specifically, health professionals have regarded the anticipated post-transitional heterosexual behaviour of trans adults as predictive of a good outcome of cross-sex hormones and gender-confirming surgeries. This article reviews the current literature according to the question of whether the sexual orientation of trans people is linked to outcome measures following transition-related interventions. A comprehensive review was undertaken using the Medline database, searching for empirical studies published between 2010 and 2015. Out of a total of 474 studies, only 10 studies reported a follow-up of trans adults and assessed sexual orientation in the study protocol at all. Sexual orientation was predominantly assessed as homosexual versus non-homosexual related to sex assigned at birth. Only one 1 of 10 follow-up studies found a significant association according to the outcome between groups differentiated by sexual orientation. Empirically there is no link between sexual orientation and outcome of transition-related health care for trans adults. In order to provide comprehensive health care, we recommend asking for sexual behaviours, attractions and identities, as well as for gender experiences and expressions; however, this knowledge should not drive, but simply inform, such comprehensive care.

"I would have preferred more options": accounting for non-binary youth in health research

As a research team focused on vulnerable youth, we increasingly need to find ways to acknowledge non-binary genders in health research. Youth have become more vocal about expanding notions of gender beyond traditional categories of boy/man and girl/woman. Integrating non-binary identities into established research processes is a complex undertaking in a culture that often assumes gender is a binary variable. In this article, we present the challenges at every stage of the research process and questions we have asked ourselves to consider non-binary genders in our work. As researchers, how do we interrogate the assumptions that have made non-binary lives invisible? What challenges arise when attempting to transform research practices to incorporate non-binary genders? Why is it crucial that researchers consider these questions at each step of the research process? We draw on our own research experiences to highlight points of tensions and possibilities for change. Improving access to inclusive health-care for non-binary people, and non-binary youth in particular, is part of creating a more equitable healthcare system. We argue that increased and improved access to inclusive health-care can be supported by research that acknowledges and includes people of all genders.