Children can have gender identity disorder - in fact, some people with the condition demonstrate symptoms by the time they're two years old. Children with gender identity disorder usually insist that they are or will become the other sex. They usually want to dress and act like the other sex, including having more friends of the opposite sex and preferring games and activities of the other sex. Children may also insist on urinating like the opposite sex - for instance, girls may insist on standing up to urinate, while boys may only urinate while sitting. By the time they reach adolescence, most people with gender identity disorder are disgusted by their own genitals and secondary sex characteristics and want to get rid of them. If you think your child may have gender identity disorder, talk to a doctor.