The expression “natural born killer” is perhaps not an exaggeration. The DNA of serial killers, as well as those who have committed numerous especially serious crimes, contains a “gene of violence.”
Serial killers and other criminals who have repeatedly committed serious crimes – robbery, grievous bodily harm – may be “programmed” to maim others.
A study published in the scientific journal Molecular Psychiatry explains why most violent crimes are usually committed by the same “maniac”, “serial killer” or a very small group of offenders. And mostly men.
For the first time, neuroscientists have set themselves the goal of studying the genetic “baggage” of as many people as possible, who over and over again demonstrate extreme manifestations of cruelty.
“We found two genes that are mainly responsible for aggressive behavior,” says Jari Tiihonen, professor of clinical neuroscience at the Karolinska Institute in Sweden, who led the study. “In addition to these, there are probably dozens or hundreds of other genes, but their influence is not so pronounced.”
About 20% of the world’s population carry at least one of two variants of the aggression genes.
Tiihonen and his colleagues chose 1004 prisoners in Finland to participate in the experiment. Of these, 184 refused to participate, and 26 were excluded due to a diagnosis of psychosis. Blood samples were taken from the rest. It turned out that all samples contain one or both variants of the CDH13 gene and the so-called “warrior gene” MAOA.
The “warrior gene” is involved in the production of the neurotransmitter dopamine and, in combination with alcohol and drug abuse, provokes a hormonal storm of aggression.
“If the natural production of dopamine in the body is reduced, its content in the brain can increase significantly when alcohol, cocaine or amphetamines are taken,” explains Tiihonen. “These substances are known to provoke a burst of dopamine and aggression.”
The CDH13 gene, for its part, is responsible for the development of connections between neurons in the brain. This gene plays a key role in causing Attention Deficit Hyperactivity Disorder.
Those with both variants of these genes are 13 times more likely to commit especially serious crimes. If you add alcohol and other chemicals to the genes, the recipe for disaster is ready.
The study also helps explain why most serial killers are male. The “warrior gene” MAOA is located on the X chromosome, men have one copy, and women have two, since they have two X chromosomes, explains Tiihonen. “Therefore, if one copy of a gene in the female body is more active than the other, a copy from the other X chromosome “balances” it. Men are unlucky in this sense – they only have one copy of the gene.
And here are the results of another study conducted with the participation of 100 prisoners in the United States and published in the scientific journal Psychiatric Genetics: the MAOA gene is associated with higher crime rates if its carrier experienced physical and psychological abuse as a child.
“The relationship between genes and the environment in which we grew up is very important for understanding the differences in crime among people with a high level of criminal activity,” says study author Todd Armstrong from Sam Houston University (USA).
Tiihonen agrees that environmental conditions, in particular childhood abuse, are important to consider. “In addition, our ability to understand the nature and consequences of our actions and control our behavior is of great importance.”
According to him, about 20% of the world’s population are carriers of at least one of two variants of the aggression genes. It is clear that not all of these people are murderers. The genes that we carry in ourselves can provoke aggression, but they are far from the only reason that pushes a person to crime.
In the comments to the study on the site, readers share interesting observations.
“I am a psychiatrist, I had to work with violent aggressive patients. According to my observations, there are people who are naturally inclined to take care, create something new, create, but there are also born destroyers – they are either not able to resist the impulse to kill, or killing gives them pleasure, they want more and more.
This fact is hard to accept for civilized people who only see violence in the news and movies. Unfortunately, whatever the reason – genes or a difficult childhood, environment – it is impossible to change such killers. Rehabilitation is a dangerous illusion. There will always be a need to shield us from them, to keep us as far away as possible.”
To be on the side of good or evil depends only on us, if we are not talking about mentally ill people
“Once upon a time, the ability to kill the enemy was a survival advantage – people lived by the principle of “kill or be killed”. Today, life requires us to unite and help each other – otherwise the planet will not survive. Unfortunately, man had too little time on Earth to create a truly civilized society. This process is still going on.
We inherited the genes of primitive times, but over time they will be replaced by genes of friendliness – we will learn to be less warriors and more – members of the same team. We have lived hundreds of thousands of years without civilization, and only recently have we come to what we call normal life, when laws work and all members of society have equal rights.”
“To be on the side of good or evil – the choice depends only on us, if we are not talking about mentally ill people. Genes cannot be used to judge the innocent, those who have no intention of committing a crime. Scientists still cannot figure out whether it is good or bad to drink milk – and now they are taken to predict whether a good person or a murderer? Funny”.