This article explores theoretical and empirical issues in the application of clinical neuropsychological evidence to forensic issues in the criminal law. The nature of forensic neuropsychological evaluations is discussed with reference to issues of competency to stand trial, criminal responsibility, and other competencies in the criminal process. Examples of specific disorders relevant to criminal law standards are presented, together with data estimating the prevalence of brain dysfunction in criminal and forensic populations. Research is also reviewed on the role of neuropsychological brain dysfunction in the etiology of violence and criminally relevant behavior. Finally, empirical and ethical issues concerning the applicability and admissibility of forensic neuropsychological data in the criminal context are discussed.
The underlying assumption is that brain dysfunction left the offender in a state of diminished responsibility. He couldn’t help himself. His dysfunctional brain made him commit the crime.
Now, the point of this post is not to debate the validity of that defense, as such. Instead, I’m simply going to note that this assumption generates a dilemma for most of its proponents.
For most folks who use this defense are secular physicalists. For them, the brain makes us do whatever we do. We lack the freedom to veto what our brain perceives or directs the body to do. For better or worse, the brain calls the shots.
This is true regardless of whether or not the agent is neurologically impaired or unimpaired.
Suppose a sociopath lacks compassion because his brain is defective. Due to brain dysfunction, he has no conscience.
The difference between an empathetic agent and a sociopathic sociopath is that natural selection selected for altruistic brains, since altruism confers a survival advantage on the species. Like drones that go on a suicide mission to protect the queen. Drones are expendable in a way the queen is not. A queen can make new drones, but drones can’t make a new queen.
However, this means an altruistic brain is the byproduct of an amoral process. Natural selection has no ethical criteria.
Therefore, from the standpoint of secular physicalism, isn’t everyone in a position of diminished responsibility? A compassionate agent is just as helpless to resist his altruistic impulses as a sociopathic agent is helpless to resist his murderous impulses. In both cases, his brain won’t allow the agent to stop himself.
What is more, in both cases, the brain is the byproduct of an amoral process, whether or not he’s neurologically impaired or unimpaired.
A Christian dualist or even a Christian physicalist (unless he’s a libertarian) could still invoke forensic neuropsychology without generating the same dilemma.