Using brain scans and research, scientists have discovered a number of internal factors that serial killers have in common.
An abnormal construction of the brain, abnormal brain activity and extra chromosomes are three factors that detectives and doctors can pay extra attention to if they are looking for a serial killer in the future. Popular Science writes that.
According to Kent Kiehl, professor of neuroscience, the brain of a serial killer is abnormal. And 50% of these abnormalities can be attributed to the genes.
1. Smaller areas of the brain
Professor Kent Kiehl has interviewed more than 4000 American criminals and scanned their brains, and finds that psychopaths have less so-called gray matter in their brains than others.
Gray matter is an important part of the central nervous system, which includes nerve cells, blood vessels and synapses.
Kiehl also saw from the brain scans that psychopaths have a smaller amygdala than healthy people. The amygdala is also called almond core and is an area in the temporal lobe of the brain. Fear and defense are here.
2. Error in the chromosomes
Another scientist who has examined serial killers is the forensic psychiatrist Helen Morrison.
According to her, killers in many cases an extra chromosome.
The American serial killer Bobbie Joe Long, who is waiting for the death penalty for the murder of at least 10 women, has an X chromosome too many.
Bobbie Joe Long. Photo: Wikimedia
Because of that extra X chromosome, his body produced too much estrogen at puberty, causing him to develop breasts. And that, according to Morrison, triggered feelings of shame and anger at Long.
Another example is Richard Speck, who tortured, raped and murdered eight nursing students in 1966. He had an extra Y chromosome.
3. Deviant brain activity
Neuroscientist Jim Fallon from the University of California did a lot of research into the brain activities and genes of mass killers. And his results show that some people are destined to become violent.
Fallon studied the brains of psychopaths with the help of CT scans.
He found that sociopathic behavior - for example the inability to suppress anger and violent tendencies - is related to a low activity in a certain part of the brain stem.
Although the genes have up to 50% influence, the scientists point out in Popular Science that the environment still plays a major role in the question of whether someone with these brain disorders actually turns out to be a murderer.