The Origins of Violence
What causes serial killers to commit the acts they do? Is it psychological, genetic, a combination of both? Many researchers have studied killers' childhoods and brains in order to answer this question. We know several facts. Hormones like testosterone, transmitters in the brain like serotonin, and blood abnormalities like hypoglycemia are things that could potentially cause increased violence in a person but we don't know for sure. However, many biological factors don't have to be hereditary. They could be caused by a head injury, poor nutrition, or environmental events, such as exposure to lead paint.
We know that about 90% of murderers and rapists are men and between the ages 18-24. Mental disorders only contribute to 3% of violence in America, so other factors have to do with nurture, like bad childhood experiences, irresponsible parents, dropping out of school, drugs and alcohol, etc. Even bad nutrition seems to have an effect on a child growing up. Four out of five violent offenders in prison never finished high school and about one-third are alcoholic. It's proven that the earlier kids start to drink, the more likely they will become violent as an adult. Also, if a child is abused when they are little, it doubles the risk that they will be violent as well.
A majority of serial killers have a history of sexual and physical abuse during childhood. *In half of the serial killers families, the biological father had left before the child was 12 years old. In the cases where the father didn't leave, he was domineering and abusive. *Delinquent acts such as pyromania, theft, and cruelty to animals were present in the childhoods of most serial killers.
Many serial killers are arrested or put in mental hospitals for less serious behaviors before the killing begins. For example, many tortured animals before they moved on to humans.
A study by Samuel Yochelson and Stanton Samenow (1988) pointed out that a high proportion of serial killers are ‘highly sexed’ in childhood, and have been known to look into bathrooms through keyholes on females undressing, or initiated sexual games - sometimes amounting to rape - with girls at school.
This is another early childhood sign that can be connected to serial killers. Many would elaborate violent fantasies as early as age seven and these 'day dreams' develop into their manhood when they're finally on their own in the real world. The three traits of serial killers are dreaming, compulsive masturbation, and isolation. They kill for the thrill, dominance, or sexual satisfaction and they choose to do it over and over again.