 Because a four-year-old isn't going to raise his hand and say, yes, Mrs. Smith, the claim that a person can be a male physically and yet a female in some ambiguous spiritual sense strikes me as the strangest and most schizophrenic form of mind-body dualism and is at best a religious conviction which has no place in a curriculum ostensibly based in science. Now, even the smartest four-year-old isn't going to say that. They're just going to sit and nod their heads or stare blankly as the seeds of insanity are planted in their helpless minds.