What are some of the factors that made Tom's childhood difficult?

Tom Ripley was orphaned at a very young age when his parents were drowned on a boat in Boston Harbor, inspiring a life-long fear of water. Tom was raised by his Aunt Dottie, a woman of comfortable means who begrudged every cent she spent on her nephew. She belittles the boy, constantly telling him he is a "sissy," just like his father. In this cold environment, Tom matures into a young man who is incapable of feeling empathy or sympathy for any other human being. He has no understanding of right and wrong, but clearly understands the necessity of not being caught.