Let's all get a few things straight before we all start being angry at each other. Gender =/= sex. Sex is whether you have a penis or a vagina (and/or other sexually dimorphic traits). Gender is the mental aspect of it. It's not a decision nor is it really conscious. It's just inherent to a person. Your gender doesn't always match your sex. When it doesn't, you have something called GID (Gender Identity Disorder). Another word for having GID is transgendered. These people are born with the gender opposite to their sex and they become disphoric at the dissonance of their sex and gender. To not be disphoric, they take hormones and gave surgery to make their sex match their gender. They are not changing their gender, they are changing their sex. This is important to remember.