Elsevier

Medical Hypotheses

Volume 78, Issue 5, May 2012, Pages 626-631
Medical Hypotheses

Alternating gender incongruity: A new neuropsychiatric syndrome providing insight into the dynamic plasticity of brain-sex

https://doi.org/10.1016/j.mehy.2012.01.041Get rights and content

Abstract

Between the two extreme ends of human sexuality – male and female – lie a poorly understood and poorly studied spectrum of ambiguously defined sexual identities that are very much a part of the human condition but defy rigid classification. “Bigender” is a recently formed sub-category of transgenderism, describing individuals who experience a blending or alternation of gender states. While recognized nominally by the APA, no scientific work to our knowledge has addressed this fascinating condition, or proposed any physiological basis for it. In addition, the alternation aspect has not been proposed as a nosological entity distinct from blending. We present descriptive data suggesting that many bigender individuals experience an involuntary switching of gender states without any amnesia for either state. In addition, similar to transsexual individuals, the majority of bigender individuals experience phantom breasts or genitalia corresponding to the non-biologic gender when they are in a trans-gender state. Finally, our survey found decreased lateralization of handedness in the bigender community. These observations suggest a biologic basis of bigenderism and lead us to propose a novel gender condition, “alternating gender incongruity” (AGI). We hypothesize that AGI may be related to an unusual degree or depth of hemispheric switching and corresponding callosal suppression of sex appropriate body maps in parietal cortex- possibly the superior parietal lobule- and its reciprocal connections with the insula and hypothalamus. This is based on two lines of reasoning. First, bigender individuals in our survey sample reported an elevated rate of bipolar disorder, which has been linked to slowed hemispheric switching. We hypothesize that tracking the nasal cycle, rate of binocular rivalry, and other markers of hemispheric switching will reveal a physiological basis for AGI individuals’ subjective reports of gender switches. Switching may also trigger hormonal cascades, which we are currently exploring. Second, we base our hypotheses on ancient and modern associations between the left and right hemispheres and the male and female genders. By providing a case of sharp brain-sex shifts within individuals, we believe that the study of AGI could prove illuminating to scientific understanding of gender, body representation, and the nature of self.

Introduction

Under the transgender umbrella, a distinct subset of “Bigender” individuals report blending or alternating gender states. It came to our attention that many (perhaps most) bigender individuals experience involuntary alternation between male and female states, or between male, female, and additional androgynous or other-gendered identities (“Multigender”). This fascinating phenomenon is given only passing recognition in one brochure produced by the American Psychological Association [1]. Furthermore, no attention has been paid to its possible physiological basis, or to its enormous ramifications for the understanding of sex and gender. Sex and gender are most commonly considered a single entity, but dissociations between external morphology, gender identity, body image sex, and sexual orientation demonstrate that at least four components interact together create a consistent- or less consistent- sex and gender identity for any given individual. Bigender individuals who alternate gender present a unique case where single components of sex and gender may vary within an individual. For the purposes of our research we are calling this condition “alternating gender incongruity” (AGI). We seek to establish AGI as a nosological entity based in an understanding of dynamic brain representations of gender and sex. The day-to-day oscillation of something as axiomatically “binary” as sex is potentially of extraordinary importance.

A survey of the transgender community by the San Francisco Department of Public Health found that about 3% of genetic males and 8% of genetically female transgendered individuals identified as bigender [2]. To our knowledge, however, no scientific literature has attempted to explain or even describe bigenderism; a search of PsychInfo and PubMed databases returned zero results for “bigender” or “bigenderism.” This may be due to the low prevalence of bigenderism and relatively recent adoption of the term by bigender individuals. Several extraordinary observations about bigenderism, however, suggest to us that the study of this condition could prove illuminating to scientific understanding of gender, body representation, and the nature of self.

Alternation of gender states might easily be explained away by the socially constructed nature of gender and the fact that transsexual and androgynous individuals might be more comfortable exploring both masculine and feminine-associated components of their personalities. However, reports that the switches in gender typically feel involuntary piqued our interest in a possible neurological explanation for this condition. We found that many bigender individuals even report switching at inopportune moments when they would much prefer to remain in their current gender consistent with their dress and presentation. Furthermore, bigender individuals often feel that their voice, emotional response, style of thinking, social interactions, and even sense of anatomy change spontaneously and that their identification of feeling “male” or “female” tracks these involuntary changes. Several phenomenological questions inevitably arise. How frequent are the gender transitions? How rapidly do they occur? More importantly: do the four aspects of sexuality – gender identity (which sex you categorize yourself or see as others see you), sexual morphology, brain-based “sexual body image,” and sexual orientation (who you are attracted to) switch simultaneously or – at least partially – independently?

Section snippets

Survey of alternating gender incongruity

To collect some initial observations on AGI we conducted a survey posted on an online forum created by and for people who identify as bigender. This forum hosts around 600 members, some of whom contribute to the forum and others who only read material others have posted. Our complete survey is attached in Appendix A. We restricted our data analysis to individuals who reported experiencing alternating (or cycling) gender, excluding bigender individuals who felt a more static blend of both male

Participant characteristics and frequency of gender switching

Of the 32 alternating bigender respondents included in our analysis, 11 were anatomically female (identified as female at birth). Three respondents reported undergoing chromosomal sex testing and the two males who reported the results of this testing had a “normal XY karyotype.” One respondent identified as intersex but only for reasons of androgynous facial appearance. The average age of respondents was 28.6 (SD = 10.4; range 17–50 years). Five respondents (all male at birth) reported currently

Phantom body parts

We previously proposed a gender-specific body image hard-wired in the brain as a partial account of transsexuality and explanation for the phantom breasts and genitalia experienced by transsexual individuals [3]. The hypothesis was that female-to-male transsexuals – for example – had female external anatomy but their internal body image (constructed in the right parietal and insula) was hard-wired to be male. Many of them experience phantom penises with phantom erections, consistent with our

Handedness

Handedness shows associations with both gender and psychopathology. A higher incidence of left-handedness is seen in homosexuality [4], and handedness is also tied to performance on cognitive tasks such as mental rotation that traditionally show sex differences [5]. Individuals with schizophrenia exhibit higher rates of left and mixed handedness, while individuals with bipolar disorder 1 exhibit greater lateralization of handedness than nonpsychiatric populations. These differences in

Discussion

What could cause such a powerful change in sense of gender on such a frequent time scale? We propose – and are currently investigating – several related theories of alternating gender incongruity: (1) unusual, amplified patterns of functional hemispheric dominance might result in alternating suppression of brain networks orchestrating more “male” or “female” cognition and emotion; (2) unusual patterns of hemispheric dominance might relate to alternating patterns of sympathetic/parasympathetic

Conclusion

In 2007 we suggested that the systematic study of transsexuals could advance understanding of how nature and nurture interact to link brain-based internal experience of body image with external sexual morphology [3]. We believe that the study of bigender individuals, who alternately exhibit congruence and incongruence of brain-based body sex with external, morphological sex could provide significant insight into determinants of brain-sex and malleability of gender. Bigender individuals afford a

Conflict of interest statement

The authors do not report any conflicts of interest in the current study.

Acknowledgements

We are grateful to RVA for drawing our attention to bigenderism and to RVA and other bigender individuals for providing critical insights into alternating gender.

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