Abuse is what causes (usually) people to be fukked up. Look at all the famous serial killers, all of them experienced something extremely traumatic growing up. They aren't just born with this fukked up brain. It is molded and shaped by their environment
Children suffering abuse develop a range of maladaptive, anti-social and self-destructive behaviors and thoughts by trying to cope with the abuse (Newton, 2001). Usually, children who are abused suffer from aggression, behavior problems, depression, compulsive sexual behaviors, social withdrawal, and alcohol or drug abuse (Newton 2001). Some people overcome their emotional trauma as adults, but others are psychologically damaged forever. Those who are severely affected by their abuse either kill themselves, or begin a violent rampage and killing spree that targets the innocent members of society.