The New York Times has an excellent article about the fallacy of assuming that a brain-based explanation of behaviour automatically implies that the person is less responsible for their actions.
The piece is by two psychologists, John Monterosso and Barry Schwartz, who discuss their research on how attributions of blame can be altered simply by giving psychological or neurological explanations for the same behaviour.
The fallacy comes in, of course, because psychology and neuroscience are just different tools we use to describe, in this case, the same behaviour.
A brain characteristic that was even weakly associated with violence led people to exonerate the protagonist more than a psychological factor that was strongly associated with violent acts….
We labeled this pattern of responses “naïve dualism.” This is the belief that acts are brought about either by intentions or by the physical laws that govern our brains and that those two types of causes — psychological and biological — are categorically distinct. People are responsible for actions resulting from one but not the other. (In citing neuroscience, the Supreme Court may have been guilty of naïve dualism: did it really need brain evidence to conclude that adolescents are immature?)
Naïve dualism is misguided. “Was the cause psychological or biological?” is the wrong question when assigning responsibility for an action. All psychological states are also biological ones.
A better question is “how strong was the relation between the cause (whatever it happened to be) and the effect?”
In light of the Aurora shootings and the prematurely and already misfiring debate about the shooter’s ‘brain state’, this is well worth checking out.