Edward Rulloff believed that one day his brain would be valuable for science, but not for the reasons he anticipated. He was a self-proclaimed genius, but also a serial killer, and it was the latter that attracted scientific attention. After Rulloff was executed in 1871, Dr. George Burr took possession of his skull and brain, believing that these items would yield important information about criminal dispositions. They didn't.
More than a century later, cognitive neuroscience appears to be on the brink of confirming what Burr and other past researchers suspected, that certain forms of violent criminality have a neurological substrate.
During the late nineteenth century, prominent anthropologists and anatomists examined scores of criminal skulls and brains for signs of criminal insanity.
Among the most infamous subjects was Joseph Vacher, who had brutally slaughtered many young men and women in France. After his conviction and execution in 1898, his brain was divided and distributed to learned men from diverse disciplines. Each studied his piece, but they reached no consensus. Although one expert spotted signs of syphilis, another compared Vacher’s highly developed speech center to that of a prominent French statesman.
Twentieth-century psychiatrists acquired the postmortem brains of the likes of serial killers John Wayne Gacy and Fred West, as well as mass murderers Michael Ryan and Richard Speck. (Dahmer’s brain was fought over but ultimately denied to science.)
Charles Whitman, who shot at numerous people from a tower in Texas in 1966, believed his brain was disturbed. In a suicide note, he requested an autopsy. It turned out that a tumor the size of a walnut impacted the hypothalamus and amygdala.
Thirty years later, the brain of Thomas Hamilton, who slaughtered 16 children in Scotland in 1996, showed evidence of a thyroid disorder associated with mental confusion and impulsive violence.
Dr. Adriane Raine was the first to focus certain types of brain scans exclusively on murderers. He got his start in neuro-developmental criminology by attaching sensors to inmates’ skin to measure their agitation when he made a loud sound.
In another study, he discovered that children from a small island who had slower heart rates and reduced skin responses when exposed to challenges or loud noise got into more trouble than other children. However, nutrition and improved education helped to reduce their criminality later in life. It was thought that because they did not experience normal fear or distress, they did not learn from risky behavior. They also did not learn empathy.
In a review of literature in 2008, Raine and his colleagues surveyed the results of different types of brain imaging on inmates diagnosed with antisocial personality disorder. They described fMRI, PET, SPECT, and aMRI as the most widely used approaches. They examined blood flow patterns and the anatomical structure of gray matter, concluding that there are visible structural and functional impairments in antisocial, psychopathic and repeatedly violent individuals.
They narrowed down the affected areas of the prefrontal cortex to the orbitofrontal and dorsolateral prefrontal cortex, and also looked at the superior temporal gyrus, amygdala-hippocampal complex, and the anterior cingulate cortex.
The researchers predicted that people with these disorders would not respond normally to the threat of punishment, would be impaired in their moral judgments, and would poorly grasp the emotional implications of their behaviors.
Neuroscience today appears to be on track to demonstrate that psychopaths, the most persistently dangerous and criminally diverse of all offenders, fail at remorse because their brains are just different. They might be unable to fully appreciate their behavior and would have reduced incentive to guide it in prosocial ways.
Neuroscience is still young, and the images on a brain scan are not yet definitive, but as the data mount and the instruments become more precise, we’ll have to come to terms with the possibility of changes in how we deal with the most dangerous people in our midst. As yet, biology is not destiny, but those nineteenth-century scientists who made a grab for criminal brains (with the exception of Dr. Frankenstein) had the right idea.