Okay so Haley is a very mature character in One Tree Hill! In season One she was the "GEEK" so to say. She was a tutor and worked hard to get good grades and she was innocent and invisible. In season Two after dating Nathan, she became still responsible but less and less. She started "LIVING" a little instead of being invisible. She joined the cheerleading squad and became friends with Brooke and Peyton. Then she left to go on tour with Chris. You could call that responsible, Selfish, irrisponsible or more. In season three she came back and took responsibility of her life and her marriage. In season four she over came an economic struggle, a point shaving husband, a teenage pregnancy, and valedictorian. In season five and currently six, she is a loving wife and mother and friend to Brooke, Lucas, Peyton and Sam Walker. She has become a very diverse character and has grown in wisdom, strength, and love in all six seasons so far. She is probably the most well developed and mature character on the show with few exeptions.