- Mind-Reading for the Sake of Justice
1. Neuroimaging, fantasy and law
To read into the mind of another person has for a long time been a fantasy—and sometimes a vague possibility. In science fiction, there are stories of aliens who are able to decipher the thoughts of other beings using some type of device. When I was a boy, I remember reading a cartoon of Bibi Fricotin, in which Bibi, a young boy like me, found some glasses that allowed him to read other people’s thoughts. For a time, I was afraid when I came across adults wearing glasses. With such devices, privacy and childish innocence would be in jeopardy, but fortunately, this was only a remote possibility. The idea would be worrying for lay people, ethicists and lawyers, but it is only a fantasy. Recently, with the development of brain imaging, the reality of this old fantasy seems less remote and even possible. Many people and institutions are now interpreting images from the brain: physicians, of course, in their efforts to cure the human brain, but also psychologists, in their endeavor to understand the human mind better. Nowadays, the practice particularly interests lawyers. For a long time, the U.S. courts have tried to assess the truthfulness of witnesses and defendants with the aid of the polygraph. The device was not very efficient. There is now some hope that brain imaging will fare better.
In order to detect liars and deceivers, human beings have always tried to decipher the mental states of their fellows without relying on what they said or might have said about themselves. There are good reasons for this in everyday life, and we are not bad at reading facial expressions and body language; but this has limits, as we know too well (who has never been deceived in his life?), and we tend to think that it would be a good thing if we could improve our abilities in this domain. In particular, if we could reliably read the minds of other people, some drawbacks in our social and moral life could more easily be avoided. Importantly, we could detect liars and cheats, and it is a very crucial matter to assess others and to improve human cooperation (Cosmides and Tooby). It is far from clear that this would constitute a net benefit in the end, but it is not surprising that our criminal institutions are interested in mind-reading, since truth is one of the main things that interests justice.
For justice, the detection of lies is not the only topic of interest in mind-reading. The law is using, or is tempted to use, neuroscientific data in four other domains: insanity as a defense (and more generally the determination of responsibility), the prediction and prevention of serious [End Page 9] crimes, the reliability of witnesses and the restoration of competence. Besides these direct uses, there are indirect ones, such as the quantification of suffering in civil suits. A victim suffers from the consequences of an assault, and receives financial compensation for that suffering. Sometimes a victim can be tempted to exaggerate his or her sufferings to obtain more compensation, and neuroimaging could be a good device to assess a victim’s pain.
Joshua Buckholtz and David Faigman summarize this as follows: “The administration of law could not exist without mind reading, as mental state inference is central to legal decision-making” (861). Neuroimaging is only a new means of access to a person’s mental state, in order to know and assess his or her motives, intentions, emotions and decisions, mental states that are crucial to determine his or her innocence or guilt. Lie detection will be the main topic of this paper, and I will dwell on prediction and prevention at the end of my reflections, because it is a subject that could have a big impact on our social practices. I will say some words on the three remaining topics now.
An insanity defense, which is linked to non-liability, and mitigated sentences, which relate to liability reduction, are very common in courtrooms. Brain imaging can play a role in this process, as did discoveries...