Independently I had come to the same conclusion that it plays on the complex intertwining of sexual desires and sexual apprehensions to which adolescent girls are prey.
I wonder if a young male writer would be able to reproduce this effect.
This is the exact same conclusion I've come to. I haven't read Twilight but as someone who liked vampires myself as a girl I can confirm that the attraction has everything to do with romantic/sexual awakenings. But your sister was probably telling the truth when she said she doesn't know what she likes about him. For young men, I imagine sexual awakening is obvious to them (look up porn on the internet??) but for girls it is more indirect and subconscious, and much more tied up with romance and behavior than with physical attributes. Yeah the guy has to be good looking, but that alone isn't enough.
Girls love guys who are powerful, mentally and physically capable of even killing someone. BUT they are repelled by men who kill for no reason or for bad reasons. The vampire kills because he needs blood to survive. That's a good reason. Or if it's the type who lives off of rats and bagged blood from the blood bank, then he always is using self control, because drinking directly from a human is preferable. Or if he drinks but pulls away before the human dies, he always must make himself do it, it's difficult. This is self control, another kind of power that girls adore. The vampire can't lose.
And the vampire is damaged. Girls love men who are damaged (but not TOO damaged). There was a study I read about - can't remember the details - but it was about some bird, maybe the peacock. Let's say it was the peacock. Everyone knows the bigger and better the male peacock feathers the more the female likes him. This study discovered that if given the choice between a male with perfect feathers and a male with slightly damaged feathers, the female will choose the damaged one. Why? Because it is proof that the male was able to survive a fight. Females are not attracted to men who have not been tested. This also explains why so many cultures have a painful or challenging male coming of age ritual. The vampire has been tested to the max... he has had to die!
And all of this is safely secured in the world of fantasy. The girl can obsess all she wants with no fear that a real vampire will actually come bite her neck no matter how much she thinks she wants it because she doesn't
really want it. Just as you say, young girls are apprehensive; unlike males, they do not have an instinct to copulate in the same way a male does. Testosterone is the "I want it, I need it" hormone, not estrogen, and girls have minuscule amounts of testosterone compared to boys. For girls, sex is all tied up with romance and emotion. The vampire fictions provide buckets of drama, conflict and emotion, giving a girl a kind of caricature way of processing the need for emotional connection before giving herself physically to a man.
Can a guy write this? I'm sure he can if he has enough insight. I think it's rare for
young people to fully understand the minds of the opposite gender, but not impossible. More often it probably takes a few years of human observation and experience to gain you the perspective. The problem with young men is that they're in the middle of dealing with young girls right now - their take on it is colored by their own tensions. For example, a young guy might misinterpret a smile from a girl as a sexual come-on, when in reality a girl smiles at a guy for other reasons. Maybe she is just being polite. If it is a flirtatious, interested smile, it might mean she wants to get to know you, just go on a date. So if a guy writes vampire fiction, he can't just have his female MC smile at a vampire, then the vamp grabs her and drains her blood. That won't thrill a girl. He needs to give the MC that
emotional connection first. And pulling off a good fictive emotional connection that isn't just melodramatic is a whole nother subject.......
