Katrina Sifferd interviewed by Richard Marshall
Here is an excerpt:
KS: Well, for one, we won’t be able to make responsibility assessments. When you show a jury a picture of a brain lighting up in such-and-such a way it means absolutely nothing to them until somebody translates the scientific data into folk psychological terms. Expert witnesses in a trial cannot just point to a dark spot on a PET scan and sit down: the scientific data is irrelevant to the defendant’s culpability until is it translated into folk concepts that push and pull responsibility assessments in different directions. For example, an expert might note that the dark spot is a brain tumor likely to result in a severe lack of impulse control, which the jury might feel undermines attribution of the highest levels of criminal intent.
I think it is interesting that some scientific data actually seems to push responsibility assessments in both directions, or in ways unanticipated by the side offering the evidence in a criminal trial. In one high profile capital sentencing hearing, the defense offered neuroscientific evidence of psychopathy in an attempt to prove diminished capacity (and thus a mitigating factor); but instead, the jury seemed to think the data made the defendant more culpable for his actions, and sentenced him to death. Is a person whose brain shows clear signs of psychopathy less responsible because of their abnormal brain function or more responsible because their brain is abnormal (and thus they are likely to be dangerous in the future)? I think it depends on the way in which the brain is dysfunctional, and maybe the reasons why it is dysfunctional. There is a lot of important work to be done making reliable translations of neuroscientific data into folk descriptions relevant to responsibility.
KS: Different theories of punishment seem to emphasize different aspects of our cognitive capacities as most important to culpability. Bill and I have argued that deontological accounts which postulate emotional response or empathy as crucial to moral knowledge and decision-making might be more likely to excuse all psychopaths because of their apparent lack of relevant affective data. Some deontological theorists believe that a lack of appropriate emotional response translates into a wholesale lack of legal rationality. A consequentialist theory of punishment, however, may be more likely to hold some psychopaths responsible, because it emphasizes the need for rational capacities as a means to grasp and reflect upon the consequences of action given ones goals and relevant social norms (a skill successful psychopaths may possess), and not the way one feels about these consequences.
The entire interview is here.