A recently-published piece entitled Criminal Minds: Use of Neuroscience as a Defense Skyrockets cites Nita Farahany‘s finding that “[t]he number of cases in which the judges discuss neuroscience is increasing,” which she reported at the Annual Meeting of the International Neuroethics Society last month. “I can’t tell you if that’s because neuroscience is increasing in the courtroom, but I can tell you that judges are talking about it in more opinions and they’re talking about it in much more detail and depth.”
The article goes on to cite Hank Greely from the Stanford Center for Law and the Biosciences saying that “[t]hese brain scans are poker chips—if you can throw in some more evidence, it might confuse the jury, and it increases the calculation about when one settles”. “Many of these cases are appeals where defendants argue they had ineffective counsel after they’ve been convicted. They say the trial lawyer was an idiot because he didn’t get my brain scanned.”
So far so good. I’m a fan of Farahany’s and Greely’s work in the field of neurolaw, and it’s great to see this work being reported upon. But what got me feeling all spiky was the next sentence in which the reporter states: “The use of neuroscience as a defense is different from that of a psychological defense, or an insanity plea, because the diagnoses depend on the physical makeup of or damage to the brain, not a psychiatric evaluation” (emphasis added).
Different? What exactly is supposed to make it different?
In my opinion it is highly debatable whether there is any substantial conceptual difference between the use of neuroscience and of (e.g.) psychological findings or a sad narrative about the defendant’s terrible upbringing as a defense. All three (neuroscience, psychology and narrative) aim to provide an aetiology that explains something, and whether the explanation should be accepted as a legitimate excuse (or at least as a factor that diminishes guilt, or maybe only as a mitigating factor at sentencing) depends on its relevance as a factor that affects responsibility and desert (and possibly other punitive aims such as deterrence, rehabilitation, etc).
Thus, if it is not explained how the neuroscientific evidence (whatever that means, see the next paragraph) is meant to connect to cognitive and volitional (and perhaps other) criteria for responsibility, or how it is meant to provide an acceptable excuse, or to act as a mitigating factor (e.g. by highlighting relevant mental disorders), then the main difference will stem simply from the fact that it is not apparent why such evidence should even be seen as relevant. As Stephen Morse often points out, merely having a hole in your head is not an excuse; rather, it’s what the hole evidently does to one’s mental capacities that matters.
Regarding the question of precisely what gets classified as “neuroscientific evidence”, I flag this issue because when “neuropsychological testing” (which is basically behavioural testing with some neuropsych theory sitting around in the background about how the observed behaviour might relate to brain features) and claims like “Alcohol affects the brain’s function” get picked up in database searches as instances of “neuroscientific evidence”, then this makes me wonder whether what we’re really seeing is not an increase in the prevalence of neuroscientific evidence used in courtrooms, but rather an increase in the prevalence of neurolanguage used in courtrooms. As the public becomes more familiar with brain-based terminology, they’ll undoubtedly say things like “My brain is all confused” rather than “My mind is all over the place”, but unless the mere use of this brain-based terminology actually has some appreciable and unjustified/undesirable effect on people’s reasoning – e.g. unless people will suddenly be more likely to say things like “Oh, well if it’s your brain that got confused, rather than just your mind, then hey that’s OK that you failed to make that all-important decision” – then I just can’t see why this is something that we should be that worried about.
Naturally, none of this takes anything away from the fantastic work that Nita Farahany and Hank Greely are doing. It does however provide a better context for understanding what might be significant or important about Nita’s findings — namely, that mere neurobabble (whether this takes the form of failing to connect brain scan anomalies with legally-relevant criteria, or the form of swapping more familiar terms like “mental disorder” for less familiar terms like “brain anomaly”) should not be permitted to influence the outcomes of legal cases. Neurobabble must be relevant before we permit it to do this.