I've heard about that before. Why is that, exactly?
This just raises more questions. What the hell is "two-spirit"? How can something be "genderless". What's the difference between "bisexual" and "pansexual"?
That diagram is just trying to combine a bunch of gender concepts within the relatively narrow female-male continuum found in western culture.
Here's my attempt at improving it:
Biological
- Most individuals have either XY or XX chromosomes, but some can have anything from XXX to XYY.
- Most individuals have either male or female genitalia, but some can have anything from one type of genitalia but one or two different types of internal gonads (testes/ovaries) to a combination of external genitalia (in the form of a big clit and so on).
- Most individuals have a particular brain structure, either a "male" or a "female" one (the difference being quite distinctive when comparing both average brain size as well as grey to white neuron matter ratio), but some can have a brain structure that falls between the male and female average.
Now, these three points usually line up in most people, but not in everyone. So while most individuals with XY chromosomes have exclusively male genitalia, and a male brain - this isn't the case for everyone. One might for an example have female genitalia, but have a chromosomal abnormality (and still have a female brain). This was a major simplification, as there are other differences between these two most common types of people, but you get the idea.
Gender
The biology of an individual, so relatively neatly being divided into two "groups", has thus given rise to primarily two "groups" when it comes to gender. Wikipedia defines
gender as "Gender is a range of characteristics of femininity and masculinity",
femininity as "(also called womanliness or womanhood) is a set of attributes, behaviors, and roles generally associated with girls and women", and
masculinity as "possessing qualities or characteristics considered typical of or appropriate to a man".
Ignore those definitions.
It is circular reasoning, and a better definition would just be "A socially recognized label for an individual that is associated with X characteristics". These could be biological, such as appearance, or just behavioral. In western society, you got "men" and "women - just two commonly accepted genders - but in other cultures you can have more than just two genders:
In the culture of South Asia, hijras (Hindi: हिजड़ा, Urdu: ہِجڑا, Bengali: হিজড়া, Kannada: ಹಿಜಡಾ, Telugu: హిజ్ర
or chhakka in Kannada, khusra in Punjabi and kojja in Telugu are physiological males who have feminine gender identity, women's clothing and other feminine gender roles. Hijras have a long recorded history in the Indian subcontinent, from the antiquity, as suggested by the Kama Sutra period onwards. This history features a number of well-known roles within subcontinental cultures, part gender-liminal, part spiritual and part survival.
In South Asia, many hijras live in well-defined, organized, all-hijra communities, led by a guru.[1][2] These communities have sustained themselves over generations by "adopting" young boys who are rejected by, or flee their family of origin.[3] Many work as sex workers for survival.[4]
The word hijra is Urdu, derived from the Arabic root hjr in its sense of "leaving one's tribe,"[5] and has been borrowed into Hindi. The Indian usage has traditionally been translated into English as "eunuch" or "hermaphrodite," where "the irregularity of the male genitalia is central to the definition."[6] However, in general hijras are born with typically male physiology, only a few having been born with male intersex variations.[7] Some Hijras undergo an initiation rite into the hijra community called nirwaan, which refers to the removal of penis, testicles and scrotum.[4]
Since the late 20th century, some hijra activists and Western non-government organizations (NGOs) have been lobbying for official recognition of the hijra as a kind of "third sex" or "third gender," as neither man nor woman.[8]
They are now recognized as a third gender in India, Bangladesh and Pakistan.
Attraction
This is tricky.
If genders are social constructs, are we then attracted (and research show that our attraction is something innate to most of us) to artificial constructs themselves or to some underlying aspect of particular social constructs (such as a commonly accepted biological trait of a "man" being a penis)?
So what would attraction (from a male) to this third gender be called?
They are neither women nor men, so it seems logical that we would invent a term to denote attraction to the gender "hijra" - which is quite a challenge.
Man is attracted to Woman - Heterosexual
Man is attracted to Man - Homosexual
Man is attracted to third gender - ???
At least when a third gendered person is attracted to another person of the same, third gender, we can call them homosexuals.
Expression
Of course, just because "society" has a definition for "man", "woman", and so on, doesn't mean that you necessarily will follow all these criteria to the point. You might still consider yourself a "man" or a "woman", and/or some other label that has social significance (whether on a societal or a local scale), because there are some benefits to conforming to a particular label (and you might still have shared characteristics that make you feel comfortable with said label).