Neurocriminology is an emerging sub-discipline of biocriminology and criminology that applies brain imaging techniques and principles from neuroscience to understand, predict, and prevent crime.
Concept
While crime is partially a social and environmental problem, the main idea behind neurocriminology (also known as neurolaw) is that the condition of an individual's brain often needs to be included in the analysis for a complete understanding. This can include conditions such as brain tumors, psychoses, sociopathy, sleepwalking, and many more. Deviant brain theories have always been part of biocriminology, which explains crime with biological reasons. Neurocriminology has become mainstream during the past two decades, since contemporary biocriminologists focus almost exclusively on brain due to significant advances in neuroscience. Even though neurocriminology is still at odds with traditional sociological theories of crime, it is becoming more popular in the scientific community.
Origins
The origins of neurocriminology go back to one of the founders of modern criminology, 19th-century Italian psychiatrist and prison doctor Cesare Lombroso, whose beliefs that the crime originated from brain abnormalities were partly based on phrenological theories about the shape and size of the human head. Lombroso conducted a postmortem on a serial killer and rapist, who had an unusual indentation at the base of the skull. Lombroso discovered a hollow part in the killer's brain where the cerebellum would be. Lombroso's theory was that crime originated in part from abnormal brain physiology and that violent criminals where throwbacks to less evolved human types identifiable by ape-like physical characteristics. Criminals, he believed, could be identified by physical traits, such as a large jaw and sloping forehead. The contemporary neuroscientists further developed his idea that physiology and traits of the brain underlie all crime. The term "neurocriminology" was first introduced by James Hilborn (Cognitive Centre of Canada) and adopted by the leading researcher in the field, Dr. Adrian Raine, the chair of the Criminology Department at University of Pennsylvania. He was the first to conduct brain imaging study on violent criminals.
Major studies Many recent studies have revealed that sometimes structural and functional abnormalities are so striking that anyone can see them. Some violent offenders, however, have subtle structural or functional abnormalities and even highly experienced neuroradiologists cannot detect these irregularities right away. Yet, the abnormalities can be detected using brain imaging and state-of-the-art analytic tools.
Neurophysiological studies
Studies on structural deficiencies suggest that people consistently behaving antisocially have structurally impaired brains. The abnormalities can be either of general character or affect specific regions of the brain that control emotions, aggression or are responsible for ethical decisions:
Low number of neurons in the prefrontal cortex. A study in 2000 determined that people with a history of persistent antisocial behavior had an 11 percent reduction in the volume of gray matter in the prefrontal cortex, while white matter volume was normal. Similarly, A 2009 meta-analysis study, which pooled together the findings of 12 anatomical brain-imaging studies conducted on offender populations, found that the prefrontal cortex of the brain is indeed structurally impaired in offenders.
Underdeveloped amygdalae. Two studies found that both the left and especially the right amygdalae are impaired in psychopaths. The psychopaths had on average 18 percent reduction in the volume of the right amygdala.
Cavum septi pellucidi maldevelopment. A study in 2010 suggested that people with cavum septi pellucidi were prone to psychopathy, antisocial personality disorder, and had more charges and convictions for criminal offenses. This brain maldevelopment was especially linked to lifelong antisocial behavior, i.e. a reckless disregard for self and others, lack of remorse, and aggression.
Bigger right hippocampus. A 2004 study suggested that the psychopaths' right hippocampus that partially controls emotions and regulates aggression was significantly bigger than the left. This asymmetry was also true in normal people, but it was much more noticeable in psychopaths.
Increase in the volume of the striatum. A study in 2010 found that psychopathic individuals showed a 10 percent increase in the volume of the striatum.
Damage by foreign objects. A large number of studies on structural damage by foreign objects convincingly shows that adults suffering head injuries damaging the prefrontal cortex show impulsive and antisocial behavior that does not conform to the norms of society. There is a number of famous life stories showing the same causal connection. For example, P. Gage was a well-respected, well-liked, and responsible gentleman. In 1848 because of a construction accident he suffered a serious damage to his brain when a metal rod propelled by an explosive entered his lower left cheek and exited from the top-middle part of his head. Gage healed quickly. After that accident, however, he became erratic, disrespectful, and vulgar. Gage had been transformed from a well-controlled, well-respected person to an individual with psychopathic traits.
Damage by tumors. There is also a number of famous U.S. criminal cases showing that damage of the brain by tumors can result in the same transformation as the damage by foreign objects.
Charles Whitman, for instance, was a young man who studied architectural engineering at the University of Texas. Whitman had no history of violence or crime. As a child, he scored 138 on the Stanford-Binet IQ test, placing in the 99th percentile. He was an Eagle Scout, volunteered as a scoutmaster, and served in Marine Corps. In 1966 Whitman unexpectedly killed his mother as well as wife, ascended the belltower of the University of Texas, Austin, and fired a rifle at students below. He killed 15 people and wounding 31 more before police officers shot him. Whitman in his final note complained of inability to control his thoughts and requested an autopsy, which revealed a brain tumor in the hypothalamus region of his brain, a growth that, some hypothesized, put pressure on his amygdala.
Another example would be Michael Oft. Oft was a teacher in Virginia who had no prior psychiatric nor deviant behavior history. At the age of forty, his behavior suddenly changed. He began to frequent massage parlors, collect child pornography, abuse his step-daughter, and was soon found guilty of child molestation. Mr. Oft opted for a treatment program for pedophiles, but still couldn't resist soliciting sexual favors from staff and other clients at the rehabilitation center. A neurologist advised a brain scan, which showed a tumor growing at the base of his orbitofrontal cortex, compressing the right prefrontal region of his brain. After the tumor was removed, Mr. Oft's emotion, behavior and sexual activity returned to normal. But after several months of normal behavior Mr. Oft again began to collect child pornography. Neurologists rescanned his brain and found that the tumor had grown back. After the second surgery removing the tumor, his behavior has been totally appropriate.
Neurofunctional studies
Similarly to neurophysiological studies neurofunctional showed that brains of criminals and psychopaths not only are structures differently but also operate in a different way. As you can see below, both structural and functional abnormalities tend to affect the same areas of the brain. These are the major abnormalities found:
Lack of Activation in the Prefrontal Cortex. A number of studies replicated the observance that violent criminals' brains showed a significant reduction in prefrontal glucose metabolism.
Reduced Activity In The Amygdala. A study found that individuals with high psychopathy scores showed reduced activity in the amygdala during emotional, personal moral decision-making.
Dysfunctional Posterior Cingulate. Two studies found that posterior cingulate functions poorly in adult criminal psychopaths and aggressive patients.
Reduced Cerebral Blood Flow in Angular Gyrus. A couple of studies found reduced cerebral blood flow in angular gyrus of murderers and impulsive, violent criminals.
Higher Activation of Subcortical Limbic Regions. A 1998 study showed higher activation of subcortical limbic regions of two groups of reactive and proactive murderers, especially in the more "emotional" right hemisphere of the brain.
Functional Disturbances of the Hippocampus and Its Parahippocampal Gyrus. A number of studies suggest that this region of the brain is not working properly in murders and violent offenders in general.
Differences in hormone levels: A 2022 study observed reported crime and hormone levels–mainly that of testosterone and cortisol–within a population of university students as consenting participants. Results from the research found that there was a positive direct correlation between testosterone levels and criminal behavior, particularly in terms of impulsive behavior and aggression. However, further tests may need to be conducted to determine if those behaviors are connected to criminal behavior through dominance-seeking behavior associated with testosterone or if it is more so due to testosterone's influence in the mesolimbic reward system by instant gratification related to committing crime. It was also found that cortisol–a major hormone in the stress response system–in both high and low levels is correlated with an increase in criminal behavior. In response to stress or threats, high levels of cortisol boost energy, suppress the immune system and increase cardiovascular activity while low levels are associated with signs of psychopathy including a lack of empathy. The two hormones were found to interact to create influence on criminal behavior with low levels of cortisol and baseline levels of testosterone correlating with income-generating crime.
Effects of drugs: Illegal drug use and drug abuse are found to be highly correlated with antisocial behaviors leading to crime. Drugs function to mimic and take the place of naturally occurring neurotransmitters–or chemical brain signals–that activate brain chemical receptors and affect arousal, mood, as well as physiological and cognitive function among other neurophysiological effects. In cases of addiction, particular drugs may affect the brain's rewards system, making it overly sensitive to the drug: thus making naturally occurring, healthy behaviors less rewarding and increasing deviant behaviors like attention-seeking, impulsivity, and aggression–often related to withdrawal behavioral traits–all of which can promote criminal behavior. In particular, inhibition caused by drug use can impair regular brain functioning, especially that of the pre-frontal cortex, impairing the ability to make decisions and perform higher-level thinking and reasoning that is otherwise critical in preventing criminal and deviant behaviors.
Ethical Concerns
Free Will