My guess is that the author (Stephenie Meyer) is an INFP. From what I've read of her work, she's very much an Fi type, and her zany notions about how vampires, werewolves, and the like work are clearly Ne. I mean, how could anything but Ne come up with glittering vampires?
Therefore, the main character Bella is very likely written as an INFP, seeing as the writer seems to be pouring herself into the character. (I would assume this is a common trait with IxFP writers.) She's emotional, open to possibilities, non-judgemental, and the only thing about her that isn't INFP is that she's got a lot more guts - I'm sure because in the author's perfect world, she does too.
Exactly, which will also explain her perceptiveness inherited from her ENFP mom.
Alice -the psychic- Cullin is written as a wierd mix of ENFP and INFJ, which comes off to me as the writer knowing an INFJ but only really understanding that INFJ's ENFP side, or worse, simply forcing her own sensibilities into the character because she (the writer) can't grasp how INFJ minds work, in which case she's mocking INFJs with this character (unlikely for an INFP to do). I think it's most likely the former. She knows an INFJ in real life who does a lot of that 'psychic' stuff, but wants her to loosen up and be more like this character. Clearly Twilight is the INFP author's fantasy world where everything is as she wants it.
She's clearly an Ne-dom using Ni shadow function and I'd say she's more Fi/Te than Fe/Ti. She doesn't read people very well, but is good at organizing with her Te.
Jacob is clearly an ISTP. He sees things as they are, lives in the now, fixes things, is quiet, and generally detached emotionally. He's the reliable guy that women seem to always look at as a back up plan in case the 'ultimate guy' doesn't pan out, and I doubt there is another type that would fill that role in the INFP author's mind better than an ISTP - especially when her real life father is likely this type. Freud would be proud.
Yes, he has well developed Fe as an ISTP.
Jasper... the crazy one that seems alarmingly close to coming out of the closet... is probably the least likely to have any real life character reference other than an ENTP that annoyed the author when she was younger and she still has no idea why.
More like ISTJ, Si-dom with Te to get on Fi-dom Bella's nerves. He lacks Fe.
And then there's the villain of the story - Victoria. I have to stop a moment and swoon over the actress here... (Rachelle Lefevre). Rowr... okay... where was I? Oh yes, this chick is CLEARLY based on the INFP author's ENFJ worst nightmare in real life. It is clear that this character is based on an ENFJ who found fault with something the INFP did (and of course INFPs never do anything wrong) and when the ENFJ tried to correct the behavior, the INFP decided she was a villain and was out to get her. This character has very clear ENFJ traits. She doesn't quit. She bases all of her motivations on her ideals. And, she's a flaming bad ass. If you doubt this character was based on an ENFJ, you don't know one, heh.
And James is ISTP, Laurent probably ENTP.
(You guys didn't seriously think I'd bring this up and not turn it into a fairly serious discussion about Jungian archetypes did you?)