The proposed classification scheme below is based upon the assumption that there are at least four variable dimensions to human sexuality that can and do vary independently of one another.
Beginning with the first dimension, bodily sex in its physical expression is a biological phenomenon. When considering bodily sex there are at least three considerations. The first consideration is the external morphology that determines what physical characteristics associated with sex are evident. This in most cases will be clearly male or female but will in a small minority of instances be ambiguous as in cases of partial androgen insensitivity syndrome. The second consideration is internal morphology that determines the physiological characteristics associated with sex and that will determine functionality. For example, one can have the external characteristics of the female morphology but lack the internal morphology necessary for reproduction as in cases of complete androgen insensitivity syndrome (see “Speculation on Transgender Conditions“. The third consideration is the sexing of the nervous system, especially brain structures, or neurological sex. Evidence for neurological sex is not conclusive but a considerable amount of evidence suggests that the nervous system is shaped by the degree of hormone exposure and the timing of that exposure See Male, Female: The Evolution of Human Sex Differences by David C. Geary). In some cases, the hormonal exposure may directly influence the development of various brain structures or in other cases the hormonal exposure may have an indirect effect by activating or deactivating genes related to sexing of the nervous system. Gene effects controlled by triggers such as hormones have only recently begun to receive attention in the new field of epigenetics.
The second dimension, sex identity, is the subjective sense of one’s sex. The proposal in this classification system is that sexual identity is dependent upon the neurological aspect of physical sex making it too, at root, a biological phenomenon. Sexual identity is usually male or female and is generally congruent with external morphology but can vary. At the extreme there can be a complete disconnect between one’s sense of sexual identity and both external and internal morphology. This is most likely a product of a neurological sex that is the complete inverse of bodily sex. In other instances, the neurological sex can be ambiguous. Ambiguity in most cases is represented by a mixed sexual identity which often presents as a primary and secondary identity rather than a seamless integration.
The third dimension, sex orientation, is the focus of one’s sexual interest. The proposal implicit in the classification system offered below is that sex orientation, like sex identity, is dependent upon the neurological aspect of physical sex making it too, at root, a biological phenomenon. However, sex identity and sex orientation can and do vary independently such that sex identity does not necessarily indicate anything about sex orientation. Generally, sex orientation will be reflected by orientation to external stimuli associated with bodily sex. However, it is conceivable that sex orientation could be influenced by “personality” characteristics associated with neurological sex. Commonly, sex orientation will have a single focus but it is not limited to a single focus.
The final dimension, gender identity. Gender is usually either masculine or feminine and its content is socio-cultural in nature. Gender identity is congruent with one’s configuration on the other three biological dimensions. Gender identity, however, is biological only in the sense that it is motivated by the biological dimensions described above, especially neurological sex, but is otherwise socio-cultural. By way of analogy think of hunger. Hunger is a biologically based sense of a bodily status. Hunger motivates you to seek ways of satisfying that bodily status. How the status is satisfied is almost entirely socio-culturally determined. What one eats, when one eats, where one eats, how one eats to satisfy a sense of hunger is largely socio-culturally determined while, at root, having a biological source or motivation. One’s biologically based sense of sexuality, which includes bodily sex, sex identity and sex orientation, motivates one to find avenues of expression for that biologically based sense of self. How gender identity is expressed, however, is largely determined by socio-cultural learning.
Probably in the vast majority of cases there is sufficient congruence between the independent variation of the four dimensions to call the outcome “normal” or typical. Even in a typical outcome, there is some range of variation but the range of variation is within limits considered “normal.” There are clearly many instances where there is a lack of congruence between the independent variation of the four dimensions that results in outcomes that are not considered “normal” or typical. The term normal herein is being used in a statistical sense, not in a evaluative sense. Anything that occurs is a natural outcome and should not be evaluated negatively simply because it is outside the boundaries of what is considered a typical outcome.
Of the four dimensions, gender identity is the most complex because of the many potential permutations contributed by the other three dimensions. The four subcategories used for transgender in the gender classification are adapted from The Transgender Phenomenon by Richard Ekins and Dave King. Because gender is socio-cultural, learned and subject to many social contingencies governing its expression, individuals with atypical gender identities are more susceptible to suppression of their motivation to acquire and express their gender identity or identities. Suppression of the social expression of a biologically based sense of self can contribute to the development of various psychological problems such as depression and in extreme cases can lead to suicide.
The classification system that follows is color coded, The coding of each dimension can be sequenced with the other dimensions in a chain while retaining the distinction between dimensions through a distinctive color. By way of analogy, one might think of a human sexuality code like a gene sequence. The chain of codes is analogous to a genotype consisting of four unique genes that describe different phenotypical outcomes. Two examples of dimensional codes are given at the end of each coded dimension and an example of a four dimension coded sequence with a verbal description is provided at the end.
I. Bodily Sex
A. Male (congruent morphology, physiology and neurological sex)
B. Female (congruent morphology, physiology and neurological sex)
1. External characteristics
a. Male external characteristics
b. Female external characteristics
c. Ambiguous external characteristics
2. Internal physiology
a. Male internal characteristics
b. Female internal characteristics
c. Ambiguous internal characteristics
3. Neurological sexual explication
a. Male neurological sexual characteristics
b. Female neurological sexual characteristics
c. Ambiguous neurological sexual characteristics
For example: IA or IC1c2a3b describe two different possible configurations
II. Sex Identity (subjective sense of sexual self)
A. Male (congruent with sex)
B. Female (congruent with sex)
C. Cross-sexed (full congruence absent)
1. Male primary and female secondary
2. Female primary and male secondary
3. Male/Female balance
For example: IIB or IIC2 describe two different possible configurations
III. Sex Orientation
C. Male primary and female secondary
D. Female primary and male secondary
a. Ambiguous external characteristics
b. Mixed neurological sex
For example: IIIA or IIIC describe two different possible configurations
IV. Gender Identity
2. Assertive masculine
3. Typical masculine
4. Subdued masculine
2. Assertive feminine
3. Typical feminine
4. Subdued feminine
1. Oscillating (IVA1-5 alternating with IVB1-5 where one is the primary and the other is the secondary gender identity. A true balance would probably be classified as IVC3)
b. Practicing (subsumes imaginal)
2. Migrating (transitioning from (a) to (b) or (b) to (a) below)
2. Body (subsumes role)
2. Body (subsumes role)
3. Transcending (blending IVA and IVB)
4. Negating (neutralizing IVA and IVB)
For example: IVA3 or IVC2
Thus a complete classification of an individual might be: IC1a2a3c IIC1 IIID IVC1
The above classification code describes and individual who is cross-sexed with external male characteristics, male internal physiology and mixed neurological sexual development. This individual has a mixed sexual identity where the male identity is primary and the female identity is secondary. The individual’s sexual orientation is mixed with orientation to females being primary and to males being secondary. This individual’s gender identity is transgender of the oscillating type in which there is an alternation between a masculine identity and a feminine identity. The secondary sex orientation toward males is most evident during oscillation from the male primary to the female secondary gender identity, which in turn is controlled by the male primary and female secondary mixed sexual identity.
[Note: I use transgender in a broad sense and do not limit the term to persons who transition physically into the binary alternative to their assignment at birth. Personally, I make a distinction between sex identity (biological basis), gender identity (requires a biological basis but largely socio-cultural) and sexual orientation (biological basis). I consider each to be a separate factor in every individual, in whole or part. I also consider these factors to be variable and interactive producing a wide range of outcomes. While some outcomes are atypical relative to the norm, I consider all to be natural outcomes.]