08 April 2012

Even More Rare and More Different

Considerably less common than homosexuality (crudely defined as sexual attraction to members of the same sex as opposed to members of the opposite sex), are transgender individuals, who perceive themselves to be members of a gender different from the one to which they physically appear to belong.

But, there are gender situations more rare and more complicated than either of these relatively easy to grok conceptions, which Neuroskeptic reports from a new pioneering study of more complex gender identities:

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 othergendered identities ("Multigender")... 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. 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.

If the percentage estimates are accurate, the frequencies are on the order of one individual out of a hundred thousand, or even a million (i.e. on the order of 300 to 3000 individuals in the United States).

The American Psychological Association recognized the concept in 2008.

To be clear, this isn't simply a survey of people with androgenous gender (i.e. people who are gender ambiguious) (another heavily overlapping notion is that an individual is an intersex individual or "hemaphrodite"), which is quite a bit more common (perhaps 0.1% to 1.7% of births depending on definition and research method, with at least seventeen different understood causes that differ from each other in important ways). Nor is it a survey of the much more common group of individuals who are "bisexual" (i.e. crudely defined as people attracted sexually to both men and women).

This is a survey of people who may self-perceive themselves to be male one day, female the next day, and sometimes androgeneous on another day (the actual duration of the phases varies) and is dubbed by the researchers "alternating gender incongruity" (AGI). Obviously, this would be a mite inconvenient if one wanted to try to reconcile one's self-perception of one's gender and one's physical appearance (the most commonly used medical resource for transgendered individuals) either with hormone treatments or gender reassignment surgery.

The total sample was small, because this situation is rare to the point of being undescribed in the literature, and based on surveys from a transgender Internet forum:

Of the 32 alternating bigender respondents included [some were excluded for diagnoses of DID etc], 11 were anatomically female (identified as female at birth)... One respondent identified as intersex, but only for reasons of androgynous facial appearance...

10/32 respondents agreed that their gender switches were "predictable." The period of gender switches was highly variable, ranging from multiple times per day to several times per year. A majority (23/32) of respondents, however, reported that their gender switched at least weekly [with 14 saying it switched at least once per day].

The paper is: Case, L., and Ramachandran, V. (2012). Alternating gender incongruity: A new neuropsychiatric syndrome providing insight into the dynamic plasticity of brain-sex Medical Hypotheses, 78 (5), 626-631 DOI: 10.1016/j.mehy.2012.01.041

Obviously, this is something of a first stab in the dark and its causes and nature are unknown. Is this etiologically more along the lines of multipersonality conditions where the individual does not completely lose continuity between phases, or some kind of psychosis, or is it simply an extended and more complex dimension of the same kinds of causes and phenomena associated with a transgender identity. For example, "ordinary" trangender identities are often described as prototypically manifesting in early childhood and being very stable over time. There is a formal diagnosis associated with what is commonly called multiple personality disorder, although it is a controversial diagnosis, and that condition is sometimes associated with extreme childhood trauma. We don't know much about when a bigender manifests, whether there is any particular set of other set of commonalities in the lives of these individuals, or much of anything else.

Many cases of multiple personality diagnosis after the syndrome was popularized were later considered doubtful, but the last century of so of psychiatry, psychology, neuroscience and gender studies have also caused us to recognize that individuals who are pscyhologically and perhaps neuropsychologically atypical can be rare without being non-existent. The article is not open access and not published in a particularly high profile journal.

Before making any definitive conclusions about what is happening, one would want, at a minimum, to have extensive case studies of as many individuals presenting as bigender or multigender as possible.

For that matter, a single, feature length article in a newspaper or magazine, interviewing an AGI individual, or a short autobiographical piece, would add far more insight than a simple write up of a single survey. But, one has to start somewhere and start asking questions before knowing that there is something to know.

The authors make the preliminary case for an understanding rooted in neuroscience (i.e. "hardware") rather than psychology (i.e. "software"):

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.

It is unclear from the abstract just how elevated for example, an "elevated rate of bipolar" is in the sample. Just two cases would probably be a statistically significant elevation relative to the baseline rate in a sample of thirty-two bigender individuals.

The second author is best known for prior research on phantom limbs. Associations with bipolar disorder and being ambidextreous, are interesting, at the very least.

The study also provides one more datapoint in the continuing psychological question of whether to think of gender as a construct with a small number of fixed categories, or as something involving more of a continuum, even though most people are on relatively extreme points in that continuum.

For more background, see in particular prior posts at this blog from March 1, 2008, and December 22, 2011. This post at another blog also provides a great deal of well informed grist on a variety of related subjects for your consideration.

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