How do we know people character by looking at their signature?

Looking for character models.?

• I designed a couple a characters a while ago, but now their personalities have really developed and outgrown these old designs. So now I am looking for more suitable models, but I am having a hard time "casting" them and would like your help. I want to find actual people/pictures to use as references. I am going to give a brief description of each character below, and I would like you to give me the picture you think suits them best! Thank you! Jude: Male, and appears to be in his late teens or early twenties. He should exude an air of incomprehension. He was raised in a lab, and taught to have little independent will or emotion, and became very used to a violent environment as a result. He was made to be an efficient tool. He recently has escaped that life, and is a bit dumbfounded by the normal world. He finds wonder in everything, and is constantly happy. He acts a bit like a child. He is a strange combination of innocent, ignorance, and dangerous capabilities. His original designs were a little too cat-like in the end, but I know I want him to be thin and unassuming, but have a bit of madness lurking behind his expression. He should be very boyish, and not terribly attractive. As you can imagine, a very hard character to get a hold on. He should be Caucasian, and I have Sumerian,Babylonian, Persian, and Egyptian origins in mind. Next is Jason Miles Jason is the older brother of two twins, and is in his mid-twenties. They grew up with their mother in poor conditions, and he often felt protective of his brother, and fantasized about a life of luxury; a life of suits and fedoras and jazz music and dashing James-Bond like characters. He dreamed of becoming this dashing gentleman, and in a tragic way he did become him. He and his brother were taken away from the fragile mother they adored, and Jason was put in a situation were he was used for espionage. He often took part in high-society affairs as a result, and learned how to seduce and act like that gentleman he admires, though he was tied down by the organization he worked for. His brother soon saw that Jason was lost escapist fantasy, and grew to hold contempt for him and the more promiscuous side of his work, which often never was meant to be a part of the job but acted on Jason's selfish desires. The other twin pledged himself loyal to the organization, while Jason later fled from it. Their relationship became hateful. Jason is ultimately selfish, has a bit of a mother complex, is obsessed with coming off as charming and sophisticated, his immensely ashamed of his being "used" by his organization, and overall kinda a mess right now. I had Irish/English origins in mind for him, but Austrian/German are starting to seem very likely as well. He is extremely handsome, and dareisayitsexy, and tires to act cool but their is undeniable vulnerability within him. Maxine Maxine is in her late teens, and is a stubborn, prudent girl who gave up on her childhood fantasies long ago. She has little self-awareness, is very independent, as a strong sense of justices, and is often the voice of reason. She is without a doubt a short brunette with Greek origins. She is supposed to look rather plain. Finally, Vincent. Vincent is an extremely intelligent man, who got involved with a noble group of outlaws in the past, and was needed for his technical expertise, but bluntly rejected the rest when a woman he has just met died as a result of his work (though they met through this work). He was once young, naiive, and laid-back. Now he is a grumpy-shut in and cynic that wants nothing to do with the world, and spends his days wasting away and occasionally messing with various affairs from is dingy apartment. And he is only in his thirties. His designs have varied dramatically (along with is name, so don't get bogged down by it) but mainly they have hovered between a shorter,thin, square-jawed, curly-haired, Middle-Eastern looking man, and a tall, thin, hollow-cheeked, sandy-haired Scandinavian with a large forehead. That is all, thank you for all your help!!!

• Answer:

  Jude: http://www.imdb.com/name/nm2240326/ Jason: http://www.imdb.com/name/nm2955013/ Maxine: http://www.imdb.com/name/nm1842439/ (Couldn't find a short-haired teen) Vincent: http://www.imdb.com/name/nm0906756/ This picture is better: http://www.imdb.com/media/rm1449237760/nm0906756