Harry had a horrible upbringing, too, but did he torture other kids for fun? No, he just learned how to run really fast and avoid being punched.

However, if you look at Tom Riddle - who was well cared for, if not given as much love and attention as a child should have since there were so many of them at the orphanage - what do we see? We see a kid who collects harmonicas and other odds and ends from his victims when he is ELEVEN. At eleven years old, Harry was looking forward to not having to go to the same school as his cousin. Tom was a clever, sneaky liar who assumed Dumbledore was a doctor sent by Mrs. Cole to look at him, possibly take him away to a madhouse, and then promptly told Dumbledore that Mrs. Cole was the mad one who didn't like him and that he never touched any of the other kids or anyone's pets, and that she'd made it all up. He was a manipulative, clever, and downright disturbed child.