Some time ago, the news reported that Liu Moumo, a 15-year-old girl in Heilongjiang, killed her mother in December last year to hide the body in the cold storage, and then forged the scene, until later her father found the body and called the police, after the police investigated, locked the girl's suspected crime, overnight sudden trial, Liu Moumou explained the whole process of killing his mother.
As early as April 18, 2020, the police in Xuancheng, Anhui Province, issued a notice that Yang Mouting, a girl who had previously lost the police, was violated and killed by her 13-year-old cousin Yang Mou.
Juvenile delinquency is not uncommon in recent years, so some people have asked whether there really are "born offenders" – some people are born prone to crime?
As early as December 1870, in the Italian prison of Pavia, an Italian criminologist named Lombrosso opened the head of the body of the famous bandit leader Villera and found a conspicuous depression in the occipital bone of her skull, which resembled that of an inferior mammal. It was concluded that this condition belonged to true earthworm hypertrophy.
(Image source: giphy)
It was with this inspiration that Lombroso subsequently investigated and measured the physiological characteristics of a large number of violent offenders, especially the anatomy of the brain and skull, and combined with anthropometric measurement, physiognomy analysis, tattoo characteristics and other means, put forward the theory of natural offenders, and published his famous work "The Offender".
Early research on violence was more sociological, but starting with Lombroso, more and more experts and scholars have found that genetics, living environment and living habits are all related to violent aggression.
In the 1990s, the American scholar Kofi [1] conducted chromosome tests on some male criminals and found that some criminals had an extra Y chromosome (23XYY), and he believed that men with excess Y chromosomes would be more aggressive and violent than men with normal chromosomes (23XY).
In a 1966 murder in Chicago, USA, the killer Sbecker killed 8 nurses in a row, and his later test found that he was a typical XYY chromosome abnormality.
However, research is now more from the perspective of gene polymorphism and epigenetics, looking for genes associated with violent aggression behavior, especially those associated with some neurotransmitters.
For example:
1. Serotonin (5-HT), widely involved in the functional regulation of mood, pain, and sleep
Abnormalities in this neurotransmitter can easily lead to impulsive attacks, suicidal antisocial behavior abnormalities [2]. Its corresponding genetic polymorphisms have also been associated with violent aggression and impulsive traits.
On July 1, 2008, Yang Jia carried out a violent attack on police officers at the Shanghai Zhabei Branch, resulting in the death of several police officers. Based on the personality and behavior of the offender Yang Jia, some researchers have deduced that it is basically in line with the performance of people with abnormal serotonin content in the brain [10].
2. Catechol oxidized methyltransferase
Catechol oxidized methyltransferase is a metabolic enzyme whose main role is to degrade catecholamine neurotransmitters, including dopamine. Some carriers of their associated genes, which are currently thought to be susceptible to violent aggression, have also been validated in patients with schizophrenia [3].
3. Transporters and receptors of dopamine
Dopamine in the brain endocrine mainly regulates the brain's lust, feelings, and transmits the information of excitement and happiness.
When dopamine increases, normal fears are replaced by feelings of excitement, which can lead to stronger violent aggression. Specific polymorphisms of certain related genes have also been shown to be associated with attention deficit, hyperactivity, and violent aggression in children [4].
4. Monoamine oxidase
Monoamine oxidase is an enzyme that catalyzes the oxidative deamination of monoamines and is involved in the metabolism of catecholamines such as dopamine, norepinephrine, epinephrine, and neurotransmitters such as serotonin, and is also associated with antisocial personality disorder and violent aggression [5].
5.γ-Aminobutyric acid
γ-aminobutyric acid is an important inhibitory neurotransmitter in the brain that has a sedative, anxiolytic effect, and genetic abnormalities in its receptors are thought to be associated with personality abnormalities and violent impulsive behavior [6,8].
Maybe one day, when we can fully determine the specific function and role of these defective genes, we can treat and improve these gene carriers by means of surgery to treat "rabbit lips".
not necessarily!
Violent aggression is a complex behavior caused by a combination of genetic and environmental factors.
Factors such as alcoholism, smoking, and child adversity can all have an important impact on violent and aggressive behavior.
Generally speaking, criminal acts are often the manifestation of the social defects of the personality of the offender, and the essence is his hostility, contempt or disregard for social norms and laws.
It is with these incorrect attitudes that they will choose behaviors that are not approved by society to meet their needs. However, those who have the gene of violent tendencies and those with personality defects may not necessarily commit crimes.
Because whether it is the gene carrier of violent aggression or personality defects, when they are transformed into a criminal psychological state, they must also rely on certain subjective and objective conditions, which are only necessary conditions for generating criminal psychology rather than sufficient conditions [9].
Review expert: Xu Hao | Neurosurgeon, Popular Science V
bibliography
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[2] Frankle W Gordon et al. Brain serotonin transporter distribution in subjects with impulsive aggressivity: a positron emission study with [11C]McN 5652. [J]. The American journal of psychiatry, 2005, 162(5) : 915-23.
[3] WANG Yongbai,WANG Jiakai,GANG Qingwei,LIU Jingyi,WANG Jing. Meta analysis of the association of THE COMT gene Val158Met polymorphism with violent behavior in patients with schizophrenia[J].Chinese Journal of Mental Health,2014,28(07):492-498.
[4] Guoqin Hu et al. The interaction of NOS1AP , DISC1 , DAOA , and GSK3B confers susceptibility of early-onset schizophrenia in Chinese Han population[J]. Progress in Neuropsychopharmacology & Biological Psychiatry, 2018, 81 : 187-193.
[5] Major General Liu,Yuxiu Shi,Fang Han. MAOA gene polymorphisms and aggressive behavior (review)[J].Chinese Journal of Mental Health,2017,31(07):580-584.
ZHANG Jingfeng. Childhood adversity and the effect of genes on the aggressiveness of male inmates[D].Shenzhen University, 2019.
Li Jiajue. Correlation between methylation levels and aggressive behavior in the promoter region of NR3C1 and NR3C2 genes[D].Kunming Medical University, 2020.
[8] Li Hui,Li Lei,Xu Hongmei,Zhao Ziqin,Liu Wenbin,Zhou Huaigu. Research progress on the genetic correlation of violent attack behavior in humans[J].Journal of Forensic Science,2015,31(05):381-386.
Mei Chuanqiang. Research on the Generative Mechanism of Criminal Psychology[D].Southwest University of Political Science and Law,2004.
Qin Zhonghua. On the Practical Significance of Research on the Biological Causes of Crime[D].Fudan University,2008.
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