Are criminals’ brains fundamentally different from those of non-criminals? Can we really scan the head of a child and forecast whether he or she is more likely to wind up in prison than on the police force?
These are early days for the study of the brain. We can use technology to examine the brain, to test what chemicals are present, to find differences among individuals and see how the brain responds electrically and chemically to everything from music and political ads to pornography.
But, in truth, we are not always sure what we are seeing. We don’t have large samples of people who have been carefully studied. When it comes to criminals, even the definition is unclear: Is it someone who is charged, convicted, imprisoned, confessed, paroled, remorseful? And what counts as a crime? Is Charlie Sheen a criminal, an addict, screwy or a bit of each? All these questions are highly controversial.
We need to be very cautious before we start applying our current knowledge about the brain to police work, schools, parole boards, job screening or courtrooms.
Support for being uber-cautious when it comes to neurocriminology can be found in the not-so-distant past.
Some years ago, I was visiting an academic friend in Turin, Italy. He knew I had spent a considerable amount of time humping around Italy staring at antiquities, churches and famous works of art. With a twinkle in his eye, he suggested we pay a visit to the Museum of Criminal Anthropology at the University of Turin. He assured me that this site would stand out even against the wonders of the Vatican, the Coliseum and the statue of David.
He was right. What I saw there is an instructive lesson about the dangers of over-enthusiasm when it comes to crime and the brain.
Italian surgeon theorized 'criminal brain'
The museum holds hundreds of skulls of soldiers and civilians, natives from "far-off lands," criminals, madmen, and wax models of "natural criminals." It is the collection of Cesare Lombroso, a surgeon-turned-psychiatrist at the University of Turin, who amassed this amazing potpourri of human remains in the late 19th century. Lombroso performed many autopsies and post-mortem examinations of all sorts of people, but especially of criminals and the insane. He kept quite a few parts after his work was done.
Lombroso became completely convinced that he could identify someone predisposed to crime from their appearance. External characteristics of criminality included large jaws that jutted out, low sloping foreheads, high cheekbones, flattened or upturned noses, hawk-like noses, fleshy lips, scanty beards, baldness, and long arms. He also thought that he could identify criminals by their brains through asymmetries, surface deformities and size differences.
Lombroso is the originator of the theory that criminals are born, not made. And his influence in criminology was seen everywhere from the eugenics laws enacted in the United States in the early 1910s and 1920s to Hitler’s theories about Jews, Slavs, blacks, and gypsies being predisposed to crime.
The problem is that absolutely no credible criminologist or anthropologist believes that any of Lombroso’s data are useful. He thought he was using the latest science of his day to solve the riddle of who might commit a crime. But the science of his day was just too simple, too crude, too racist and far too underdeveloped to bear the weight he wanted it to carry.
Today, our technology is much better. We can view the brain in real time. We know much more about how the brain works and how some disorders of the brain are reflected in the physiology of that organ.
Despite advances, our knowledge is limited
Still, we don’t know all that much. It's unclear how much natural variation exists between the brains of the incarcerated vs. those who are free. It's uncertain how individual brains respond to external forces: abuse, injury, violence, malnutrition, drugs, television, the internet, isolation, six cups of coffee a day or a even cheesesteak. What happens when you put a normal brain into a deprived environment or, worse, one filled with crime, violence and drugs is even less well understood.
Neuroscience is far from ready for prime time in the courtroom. When freedom and liberty —along with treatment, rehabilitation and even surgery — hang in the balance, we need far more evidence and certainty then exists right now. Cesare Lombroso’s collection of skulls and brains in Turin is all the warning we need to be extremely cautious before labeling anyone as having a "criminal" brain.
Arthur Caplan, Ph.D., is director of the Center for Bioethics at the University of Pennsylvania.