Psychopathology and Morality
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acquired sociopath, cognition, emotion, sentimentalism, rationalism, reinforcement
Tankersley's paper is a very useful summary of where we stand on two topics: the nature of psychopathy and the nature of moral cognition. The two topics are of course linked: two of the symptoms that mark out psychopaths are poor moral behavior and moral judgment. A key question guiding the discussion is: can evidence from the nature of psychopathy tell us anything about nonpathological moral cognition? Tankersley's view is that currently it cannot—not because of any paucity in the evidence coming from experiments on psychopaths, but because of conceptual confusions in the current state of the debate about moral cognition. In this reply I am a little more upbeat.
Tankersley's discussion of psychopathy takes the form of a helpful summary of the current thinking on the etiology of psychopathy, with a review of some pertinent studies on these subjects' moral cognition. The second part of Tankersley's paper is a discussion of moral cognition; she describes the current division of the debate into the moral rationalists on one side and the sentimentalists on the other, and questions the assumptions underlying the drawing of this divide. Her conclusion is that there is little in current empirical work that can help to decide between the rival views, because of the crude way these views distinguish themselves. In this, comment I suggest that we ought to be a little more upbeat about the prospects for moving the debate between the rationalists and sentimentalists forward in the light of work in psychopathology. I do not find any reason for pessimism—either about the current state of the debate or the future prospects. Most of what I have to say focuses on the second part of the paper—the discussion of the debate between moral rationalists and sentimentalists. I say a little about psychopaths first.
Psychopaths
Tankersley distinguishes psychopaths from Damasio's category of acquired sociopaths; the latter are patients who present with symptoms after a lesion to the prefrontal cortex (PFC), amygdala, and/or limbic system. She discusses symptomatic differences and etiological differences between the two, and draws some lessons about what these types of deficit might tell us about nonpathological moral cognition.
One such lesson researchers have drawn is that among acquired sociopaths, we find two distinct impairments that underlie their poor performance on a certain task—Damasio's gambling task. Damasio's gambling task is a task in prudential reasoning—a matter of working out and pursuing what is in one's own best interest. The relation between such reasoning and moral reasoning is [End Page 359] an interesting question—and it is a question that divides the moral rationalists and the sentimentalists. Moral rationalists perhaps see prudential reasoning and moral reasoning as distinct competences—dissociable; sentimentalists most likely see them as interdependent. Things may not divide quite so neatly, however; therefore, it is difficult to draw conclusions about moral cognition from experiments on the gambling task.
An interesting conclusion about prudential reasoning can be drawn from the gambling task experiments. Both patients with lesions in the amygdala and the ventromedial (vm)PFC showed similarly impaired performance on the gambling task, but their performance should be explained differently for each subgroup. Both groups fail to settle on choosing cards from the better deck, but in the case of amygdala patients, this is because they do not feel the hits of the draws they make from the bad deck; in the case of vmPFC patients, they feel the hits, but fail to associate these negative emotions with their choice (or with the deck from which the poor choice was made). Explanations such as this of how different patient groups differ provide fuel for building more detailed hypotheses about how prudential reasoning proceeds in normal subjects. It proceeds in a way that involves two stages: feeling emotional hits when a choice turns out poorly and then associating that feeling with the prior choice in a way that modifies future preference away from that choice.
So experiments on psychopaths can tell us about the nature of nonpathological prudential reasoning. Is there any reason to think that...
