This article argues against the idea that criminals are molded by their innate genes, arguing that acquired environmental factors have a greater impact. Using national crime rates, genetic modifiability, and epigenetics, this article provides evidence that acquired factors play an important role in criminogenesis and explores how society might respond to future neuroimaging technologies.
How would you feel if you were living a normal life and a neurological test showed that you would commit murder in the future? Many people would be horrified and argue that it would never happen to them. In fact, the majority of people believe that criminals are influenced by social and environmental factors, meaning that they are shaped by acquired traits. However, in the 1900s, the idea that criminals actually have a gene began to be studied and discussed in depth among neurologists. Adrian Raine’s The Anatomy of Violence argues that criminals are shaped by innate rather than acquired factors, and that there is indeed a ‘criminal gene’.
But even if a criminal gene does exist, and even if we can test to find out who carries it, how can society respond if that person hasn’t committed any crimes yet? It is very difficult to give a definitive answer to these two questions. Another question is: even if there are people who are congenitally predisposed to become criminals, isn’t the probability of committing a crime determined much more by acquired factors? I would answer “yes” to this question.
My first evidence that criminals are much more influenced by their acquired environment is the premeditated murder rate by country. While Korea and Japan have relatively low rates of 2.9 and 0.5 per 100,000 people, respectively, Mexico’s rate of 18.1 per 100,000 people is uniquely high compared to other countries. This suggests that there is no reason for Mexicans to have 10 times more criminal genes than South Koreans or Japanese. This suggests that the culture and social climate of a country has a greater impact on crime than genetics. Of course, some might argue that genes are passed down from ancestors, so people in the same country usually share the same ancestors. But if genetics is the reason for a country’s high murder rate, we should also look at another crime: rape.
Unlike the murder rate, Mexico’s rape rate is low compared to other countries. While Australia and Sweden have 91.9 and 58.6 reported rapes per 100,000 people, respectively, Mexico has a relatively low rate of 13.3. If Mexicans have a criminal gene and crime is innate, we should expect to see high crime rates regardless of the type of crime, but the data suggests otherwise.
The second rationale is that there may be people who commit crimes without having a criminal gene, and conversely, there may be many people who have a criminal gene but do not commit crimes. Of course, the criminal gene hasn’t been identified yet, and no one has analyzed who carries it, but it’s easy to prove these claims. Genes are passed down from parent to child, so if a parent is a criminal, there should be a high probability that their child will also be a criminal. In reality, however, it is rare for a criminal parent to be a criminal child, and certainly not all criminals have criminal parents. For example, the parents of Russian mafia boss Semyon Yudkovich Mogilevich were not criminals. This indirectly suggests that criminality is influenced more by acquired than congenital causes.
The third argument is that genes can be modified by changes in the social environment. This is a very strong argument because it means that even if there is an innate criminal gene, it can be modified through acquired changes. It used to be thought that genes were passed down from generation to generation and that genetic modification was uncommon except in special cases, such as mutations. However, the field of epigenetics has recently gained a lot of attention among genetics researchers, confirming that genetic changes can also occur acquired. Research has shown that it is rarely the genetic DNA itself that changes, but rather the sequence or binding of the histone proteins that wrap around the genome, which can alter a person’s personality or appearance.
More specifically, this can be seen in identical twins. Identical twins are born with exactly the same genetic traits, but as they grow up, their faces and personalities change depending on their environment. In a real-life example, one twin lived a traditional lifestyle in Japan, while the other moved to the United States and grew up with an industrialized American lifestyle. As a result, the twin who lived in Japan lived a long life, while the twin who lived in the United States suffered from diabetes and hyperlipidemia and died early. It is also not uncommon for one identical twin to be a criminal while the other leads a successful life. These changes in genetic traits due to acquired factors are the subject of a growing field of research called epigenetics.
Therefore, while criminogenic genes may be innate, they can be altered by acquired factors, and acquired factors have a greater impact on criminogenesis.
The main point of this article is that criminality is determined more by acquired factors than by innate genes. The above three rationales also explain that acquired social and environmental factors have a greater impact than genes. However, I’m not simply emphasizing that acquired factors are stronger. In this article, I’d like to propose a solution to the question of how society should respond to such technology if it becomes possible to predict future crime rates by analyzing the human brain.
