In the past decade, several Supreme Court cases have reconsidered how juvenile offenders are sentenced. In the majority opinion for Graham v. Florida (2009), the case which decided life in prison without parole was cruel and unusual punishment for non-homicide offenders under the age of 18, Justice Elena Kagan wrote, "developments in psychology and brain science continue to show fundamental differences between juvenile and adult minds."
It is not the first case to cite brain science as a mitigating factor in the courtroom-and it will not be the last. Many neuroscientists, legal scholars, and policy makers have strong opinions about how, where, and why neuroscience should be considered in the legal system. But as Nita Farahany, professor at Duke University's School of Law pointed out in her Neuroscience 2013 lecture, "Blaming the Brain: Behavioral Sciences in the Courtroom," the cat is already out of the bag. Even today, neuroscience's reach transcends mere sentencing recommendations.
Neuroscience vs. the legal system, today
During her presentation, Farahany presented a unique data set made up of more than 1,500 majority and plurality judicial opinions spanning from 2005 to 2012. To better understand the way lawyers are introducing neuroscience-related findings, she examined 84 different variables across these cases, including the date, the state, the types of offenses committed, and the types of brain-related claims made by defendants.
"What we see now is a steady increase over this eight-year timeframe of the use of neuroscience in criminal cases," she says. "What I'm coding for here is any time a judge actually talks about the use of neuroscience by a criminal defendant."
She found that most cases involved some type of homicide charge but defense attorneys were also "blaming the brain" in cases involving drug crimes, assaults robberies, burglaries, rape, kidnapping and fraud. And while many of the highest profile cases in the media show how neuroscience is mitigating sentencing recommendations, Farahany says it's a myth that's the only area of the law where it is being considered.
"We see quite a bit of it during pretrial. We see it at competency determination at pretrial, during trial waiver, withdrawal of guilty pleas, competency to stand trial, competency to assist with one's own defense," she says. "It's used quite successfully in a lot of those cases, too."
Despite what popular TV crime shows may suggest, neuroscience hasn't proven to offer that much in determining guilt or innocence during criminal trials (though it does provide a bit more help in juvenile cases). After all, a brain scan or neuropsychological battery has to compete with the more gruesome details of some fairly serious crimes. Yet, Farahany argues, brain science is changing the legal in subtle and somewhat surprising ways. Her data set showed that approximately 20 percent of brain-related claims involved ineffective assistance of counsel.
"Even in horrific crimes, courts have upheld that failing to investigate a reasonable likelihood of a brain abnormality constitutes ineffective assistance of counsel. The test for establishing constitutionally effective assistance of counsel is very stringent," she says. "In fact, even in some cases where defense counsel was asleep during substantial portions of the trail, courts said it wasn't ineffective assistance of counsel, as long as they were awake during the important parts. So imagine that merely failing to inquire about neuroimaging and a potential brain injury can be labeled ineffective assistance of counsel, while being asleep is not."
How should neuroscience be used?
At a conference press event discussing delinquency and deviant behavior, Joshua Buckholtz, director of the Systems Neuroscience of Psychopathology Laboratory at Harvard University, says that he is concerned about the way his research may one day be used in the courtroom. "There are assumptions I make and understand about my data that other people don't understand," he says. "The most important of them is the group-to-individual-difference problem. When we do our studies, we collapse the individual differences across all the data. And, in doing so, we can't, on the basis of a general trend, go back to an individual brain and make any claims about that person. It's a nuance that often escapes the legal system."
But Kent Kiehl, a neuroscientist from the University of New Mexico who studies the criminal brain, is less circumspect. "If imaging can add more and help us understand the truth, which is what good science is about, why shouldn't attorneys use it to help their clients?" he asks. "Neuroimaging is just one variable to be considered in the risk equation. It is incumbent on neuroscientists to educate those in the legal system how much variance a particular result really explains and then let the math dictate how it's weighed. Like any scientific result, neuroimaging has to earn its weight."
Rethinking our assumptions
In response to criticisms like Buckholtz's, Farahany agrees with Kiehl that public education is key. Neuroscientists should be on the hook to explain the nuances of their data, to allow each brain scan or neuropsychological battery to, as Kiehl puts it, "earn its weight."
"Refrains of, 'This evidence shouldn't make it into the courtroom,' are basically too late. It's there, it's spreading, it's expanding," she said. "If the jury is the public, and if they're meant to adjudicate and understand the role of this kind of evidence, then a broader education is essential to equip them to do so."
Farahany makes the important caveat that her data set is only a "narrow, tiny sliver of the universe." Yet, she argues, it's the best glimpse we have of how neuroscience is being used today in the courtroom. And perhaps, she says, neuroscience's most important contribution to the legal system is that it is challenging some strongly held folk psychological concepts about the retributivist nature of criminal punishment (the idea that punishment is the best response to crime).
"Neuroscience is leading many of us to ask questions about what the purpose of punishment is, and whether a better understanding of human behavior should lead us to change whether, why, and how we punish individuals. It's leading many people to make calls for rehabilitation instead of incarceration," she says. "The science may pressure us to actually confront those philosophical questions. But they cannot answer them for us. This is a societal conversation that neuroscience is just one small part of."