Transgender 101
Terminology
Admittedly these terms aren't all medically recognized, but it's good to know what they are so that there is some clarification. Another side note, these definitions are also not necessarily solidified in the medical world or even in the trasngendered community. However, these are the commonly accepted definitions.
Gender
Gender is a very confused term. Most people consider it to be the same as your sex, which is next in the defined list. However, it's not. Commonly, gender is considered to be the psychological concept of male or female. It is the presentation of a person as a male, female or otherwise. This is not to be confused with the term "Sex". Gender is within the mind.
However, this is not the only way to define gender. Some would define it as genetics. Others define it as the psychological concept described earlier. Other definitions are even being developed through current medical research. Brain Shape is one of those methods. For solidarity and less confusion, let's stick with the psychological definition. Simply put, gender is what's going on in your head.
Sex
Sex, aside from the act of sexual intercourse, is commonly defined as your genetics. This is what's between your legs; your penis or vagina. Pretty simple. Sex is the physical body.
So, with that in mind, a person's gender and sex can and sometimes differ from each other. This is where we get into the transgendered realm.
Gender Identity
This is the concept of how you percieve yourself, or identify as a man or a woman....or perhaps neither or both. There are more possibilities than two.
It is likely that everyone has a sense of who they are, as a man or a woman despite their physical appearance. However, most people are unaware of it, since their Gender Identity is in alignment with their genetic sex. This is one of the core concepts in transgender.
Transgender
Generally, this is viewed as an umbrella term, though it doesn't really have an official definition. It encompasses all gender variant behavior. So in other words, it's a category of people ranging from the cross dresser to the transsexual including all levels inbetween. It's a category.
A person doesn't have to live as the opposite gender to that which they were born to in order to be considered transgender. In most cases, transgendered individuals are invisible to the public. There are some cases when that's not true though. Next we'll cover common variants of transgender and hit a few misconceptions.
Cross Dresser
The cross dresser is the most common of gender variancies, but is also the most misunderstood of all of them. Another term used for this is transvestite, however, most prefer cross dresser. Statistics are very hard to find. This would be primarily due to the fear involved. Because of society's taboo of femininity in males, most cross dressers remain closeted, or only out to close family or friends.
The most common misconception of is that cross dressers are homosexual. This is not true. Also, contrary to popular belief, cross dressers are not drag queens. Generally cross dressers are straight males who in many cases are married with children. Sometimes they are out to their spouse about it, but often times they are severely closeted.
This term generally applies to males dressing in female clothing, since there is a double standard in modern society for manner of dress. A woman can dress very masculine and be accepted as normal or perhaps as a butch lesbian, but a male cannot wear female clothing at all. This is where the fear comes from. Being discovered as a cross dresser often times makes that individual an outcast.
There are four main identified motivations for cross dressing: eroticism, relaxation, role playing, and a desire to be attractive. Initially for many crossdressers the main motivation is the eroticism and sexual gratification. However, over time this usually gives way to just a desire to express the feminine self. Typically dressing is done in private or semi-private situations. Usually, cross dressers are comfortable with their own sex and identity. By no means are they looking for surgery. They are happy in their maleness, but want a periodical distraction from the demands of the masculine role.
Drag Queen/King
The most mainstream concept of transgender is the drag queen or king. Drag queens and kings are mostly gay and lesbian people that dress infrequently. Motivation for dressing in drag has nothing to do with a need for femininity or masculinity. Instead it is rooted in gay culture in that they are defying the categories of sex and gender. They normally don't make a big attempt at passing as the opposing gender, and in fact usually follow extreme stereotypes of that gender.
There is no evidence to suggest that drag queens dress out of any sex or gender identity confusion. It's also not for sexual gratification. The only gratification they get out of it is the response from the audience. Drag shows are very common in the queer community. So in other words, drag queens and kings dress for laughs and a good time, nothing more.
Gender Queer
This term applies to anything that doesn't seem to fit the gender dichotomy of male and female. A person can identify as non-gender or perhaps both genders. Think of gender more as a range instead of two solid roles. If you think of it that way, anyone can be any amount of masculine and/or feminine. A gender queer person it exactly that. Some use gender queer as an umbrella term much like transgender as well. That works quite well, since all transgendered people are gender variant in their own way.
Transsexual
Transsexualism is the most well known and most publicized of all the types of transgender. A transsexual is a person who's gender identity does not match their anatomical sex. Typically it's traceable back to early childhood and is the most severe of all the gender disorders. Some go through SRS or sex reassignment surgery, but not all do. The motivation behind transsexualism is just to be yourself. For these people, their anatomical sex is not who they truly are. The process in which a transsexual goes through is covered in other sections.
Gender Dysphoric
Gender dysphoria simply means "discomfort in gender", however that doesn't describe what it is to be gender dysphoric very well. The gender dysphoric isn't so much of a type as it is a stage. This is a person who is moving toward a transsexual identity, and at the same time fighting that transformation. It is a very difficult and painful place to be on the spectrum. There are three possibilities for the gender dysphoric. They may either remain in the dysphoric stage, move into the transsexual identity in which the gender identity and anatomy are opposite, or move back to an area where gender identity and anatomy are congruent. The motivation here is to simply resolve the conflict in some way.
This part of the transgender spectrum can be very hard to get through, and likely has a lot to do with the high depression and suicide rate among the trans community. Unfortunately, just about every transsexual has to go through gender dysphoric stages.
Offensive Terminology
There are several terms that are thrown around in the community that can and often are very offensive. The first of these terms is "Drag Queen". Since most people have the misconception of all cross dressers being homosexual or they simply are unaware of what a drag queen really is, this term is usually used for any male wearing female clothing. In reality, this can be very insulting to the transgendered individual. It implies the person is gay and just playing around.
The second is "shemale". This term is probably the most insulting of all of the words used to represent transgender. This term comes from the pornography industry and implies that the individual is nothing but a sex worker. Many people have only been exposed to transgender by porn sites on the internet and think that's what all transgender people exist for. In reality, transgendered people are just people trying to be themselves. It has very little if anything to do with sex. Don't use this term.
The word "tranny" is sometimes used to refer to transsexuals as well as car transmissions. The usage of this term for the automobile is fine, however, not for the transsexual. It's a bit deragatory and reduces the individual to an object instead of a human being.
Finally, you can very quickly insult a transgendered individual by using the wrong pronoun or name. When this happens it's like a slap in the face. It suggests you do not respect who the trans person it at all. If you're worried about using the wrong pronoun or name, the easiest way around it is to just ask. No one will be offended and you know for future reference.