The Triple Helix @ UChicago

Fall 2015

"Criminal Minds: The Biological Basis of Criminal Behavior" by Lindsey Jay

 

Imagine what it would be like if we lived in the world of the 2002 science fiction movie, “The Minority Report,” where psychics help to arrest would-be criminals before they commit a crime. While we cannot see into the future yet, scientists have been studying criminal behavior in the field of neurocriminology since the late 19th century in order to try to understand what differentiates criminals from the average person. 

Cesare Lombroso studied criminals and claimed that they could be identified by physical attributes, that criminality was inherited, and that criminals were a form of more primitive humans.[1,2] His findings were controversial, with suggestions that features such as a beaked nose correlated with criminality.[1] However, the idea that we could biologically predict criminal behavior fascinated many people, and it continues to be a hot topic of inquiry today. Lombroso’s claims are no longer accepted as true, but the idea that there may be a biological bases for criminal behavior motivated the creation of the discipline of neurocriminology. 

Neurocriminology centers on studying the brains of criminals in order to better understand, predict, and prevent crime.[3] With the emergence of brain imagining technologies, neurocriminology took off; now we can actually “see” and compare brains and brain activity. This new technology allows scientists to see what parts of the brain light up during various tasks, a possible gateway into understanding how people think. Neurocriminology is mainly interested in looking at the brain activity of criminals compared to that of “normal” people.[4] Scientists in the field hope to discover what types of motivations or biological bases would prompt violent behavior. 

Dr. Adrian Raine, a professor in the University of Pennsylvania’s Criminology Department, is a pioneer in neurocriminology studies. Using positron emission tomography (PET) scans, which use a radioactive tracer to study tissue metabolic activity, Raine identified a particular area of interest: the prefrontal cortex.[2,4] The prefrontal cortex is responsible for executive decision-making. In a study of 42 murderers’ brains, he found that there was much less activity there compared to those of average humans. This suggests that murderers may have less control over violent behavior since their prefrontal cortex is not as active.[2] Raine had two explanations for what causes such a lack of activity: nature and nurture. In a study done with over 100 twins, researchers found that about half of their aggressive and antisocial behavior was genetic.[2] Simply put, some people are more predisposed to violent behavior than others, much like how some are more predisposed to alcoholism. Additionally, those that are diagnosed with antisocial personality disorder (APD) are much more likely to have violent tendencies. 

The “nurture” explanation is slightly more complicated because there are so many factors to consider. Any environmental factor may play a role in shaping a person’s behavior. Raine cited something as simple as shaking a baby when it is crying to have the potential to cause head trauma and damage to the prefrontal cortex. Other factors such as lead exposure or alcohol use during pregnancy may also contribute to lower activity in the prefrontal cortex.[2] 

However, this trend of lower activity in the prefrontal cortex does not apply to all criminals. In particular, the prefrontal cortex of long-time serial killers has been shown to function normally. These types of killers have excellent control in their decision-making and have calculated plans of action, unlike murderers who spontaneously kill. Raine found that they have a reduction in the size of the amygdala, the emotion center of the brain.[2] The amygdala makes up a small portion of the brain and is involved in fear responses, conscience, and remorse (sciencedaily, wsj).[2,5] A reduction in its size may affect how long-term murderers can conduct cool, calculated decisions uninhibited by emotions. On top of that, Dustin Pardini of the University of Pittsburg and his team found that 26-year-old men with smaller amygdalas are up to three times more likely than men with normal-sized amygdala to be aggressive, violent, and to show psychopathic traits three years later.[6] 

With all these findings on criminal minds, many wonder how to prevent the creation of future criminals. Though we cannot change genetic predispositions, we can prevent events such as drinking alcohol during pregnancy and try to adjust other environmental factors. As for how to punish criminals, Raine believes that, much like in “The Minority Report,” future criminals can be apprehended based on their brain images before the crime is committed by screening all males at the age of eighteen.[3] Raine also believes that those who have suspicious brain scans should be sent to a holding facility away from society.[3] His proposal has been met with many objections, for there exist many moral implications for punishing someone for something they have not yet done. While an ideal world may include one that is criminal-free, the cost would be a restriction on people’s freedom. Raine’s ideas, though radical, spur interesting thought on how to handle crime in the future. For now, researchers are focusing on how to target and help individuals predisposed to violent behavior in other ways such as teaching them meditation techniques.[2] 

The field of neurocriminology has made great advances, but there is still much to be explored in the subject, especially how to apply the research to predict and prevent crime. In the near future, we may see a change in how we handle and prevent crime. Stay tuned.

References

[1] McFarnon, E. “The ‘born criminal’? Lombroso and the origins of modern criminology”. Historyextra. October 2015. 
[2] Raine, A. “The Criminal Mind”. The Wall Street Journal. April 2013. 
[3] Dahl. O. “Neurocriminology: The Disease Behind the Crime”. Dartmouth Undergraduate Journal of Science. November 2013. 
[4] NPR. “Criminologist believes violent behavior is biological”. NPR. March 2014. 
[5] ScienceDaily. “Amygdala”. ScienceDaily. 
[6] Miller, A. “The Criminal Mind”. American Psychological Association. Vol. 45. 2014.

 
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