One of our readers has suggested that one of us post something on last Sunday’s New York Times Magazine piece on stem cells and animals. It seems that scientists have now been injecting human stem cells into some animals to figure out the ways in which the cells might differentiate and develop, and so, as with any new medical technology or procedure, certain ethical questions are raised. Combining the cells of any two distinct species creates what is known as a “chimera,” and so when these human cells are injected into the brain of a mouse, say, we’ve got a mouse/human chimera on our hands (perhaps literally). As it’s put in the article:
Few people argue that all experiments mixing human and animal material should be banned outright. But where should the lines be drawn? “Some scientists are completely upset with even a single human cell in a monkey brain,” says Evan Snyder, a neurobiologist who has conducted chimeric experiments with Redmond. “I don’t have problems with putting in a large percentage of cells – 10 or 20 percent – if I felt it could help a patient. It comes down to what percentage of human cells starts making you squirm.”
But what precisely are the ethical issues involved here? Believe it or not, what seems to be taken most seriously in defining the ethical issues is the aforementioned what-makes-you-squirm condition, known officially (I kid you not) as the “yuck factor.”
Again, to quote from the article:
The man most identified with that term, Dr. Leon Kass, the bioethicist and current chairman of the President’s Council on Bioethics, is of the opinion that widespread feelings of repugnance may be an alarm that something is morally wrong, even if you are not able to articulate precisely why. The mouse [with a partly human immune system] and the senator [with a partly porcine heart] may not trigger a yuck because they look just like a rodent and a person. But what about a normal-looking mouse with a headful of human brain cells or a human-animal embryo that is only briefly alive and never seen?
I must confess to being less interested in the so-called ethical concerns involved in chimeras than I am in exploring the nature of the “yuck factor.” Should “feelings of repugnance” play a role in moral deliberation and the attempts to arrive at moral verdicts? One thought might be that yes, because we’re on new ethical terrain, we should take whatever we can in the way of moral data, and repugnance at least provides us with that.
There are some obvious worries with doing so, though, not the least of which being that, if this is all we have to go on, then we’re going to wind up with some seriously intractable disagreement, because there are some states of affairs about which people would disagree wildly in their degrees of squeamishness. Professional philosophers, for the most part, have had their capacity for squeamishness greatly reduced, I suspect, after years of considering rather crazy intuition-pumps and following implications to absurd ends, so their reaction to the thought of a monkey/human chimera may be more along the lines of detached curiosity than horrified disgust (or at least the former is how I would likely react, mixed in with a dash of enthusiasm). But this is just a particularized form of the standard worry about appealing to intuitions. Nevertheless, it’s particularly worrisome when repugnance is included as an important feature of moral discourse at the public policy level.
In addition, it’s entirely unclear that the “yuck” feeling is an indicator of either (a) a moral worry, or (b) a moral worry. With respect to (a), we tend to experience repugnance at all sorts of states of affairs, so why think it tracks a specifically moral concern? For example, I may be feel a “yuck” when you traipse around barefoot and I see a bit of dirt underneath your toenails. I’m obviously not undergoing the basis of a moral judgment, though. As for (b), the self-aware homophobe may still undergo the “yuck” factor when seeing two men kiss, despite his full-fledged affirmation that there’s nothing wrong – morally or otherwise – with that action. Given these facts, then, why think that a “yuck” feeling is, or ought to be, relevant to specifically moral deliberation and discourse?
Perhaps, though, if we take seriously that our “yuck” feelings are just a starting point, we can at least take them into account as one of many possible instances of moral data entering into the deliberative mix. But should we even allow this? My main worry in doing so has to do with Kass’s claim that “widespread feelings of repugnance may be an alarm that something is morally wrong, even if you are not able to articulate precisely why.” This claim immediately reminded me of the work of Jonathan Haidt, a psychologist at the University of Virginia, who has written a powerhouse article called “The Emotional Dog and its Rational Tail” [Psychological Review 108:4 (2001): 814-834], in which he summarizes a load of recent psychological literature on moral decision-making, and suggests that most of the time when we express some deep-seated emotional reaction (like “yuck”) to a morally charged situation, we are, ultimately, often drawing on an intuition that reflects how others we trust would react to the situation (this is what he calls the “social intuitionist” model of moral judgment). For example, many studies show that, when people are asked about certain harmless but morally charged situations involving, say, incest between a brother and sister, they’ll respond that it’s wrong, but when pressed for reasons they’ll eventually say something like, “I don’t know, I can’t explain it. I just know it’s wrong” (p. 814). Haidt suggests – and he seems quite right here – that when faced with morally charged situations, people simply have an intuition, which then produces a judgment about its rightness/wrongness, and then they provide, when pressed, public reasons to try and rationalize the judgment made. The public reasoning, then, doesn’t serve to produce and support the moral verdict; instead, the verdict comes first. The function the public reasoning does serve, however, is that of influencing the intuitions, and thus moral verdicts, of other people. But here’s the kicker: it doesn’t do so via its actual reasons; instead, it does so because of whose mouths emit it. This is the “I agree with people I like” heuristic, suggests Haidt: “If your friend is telling you how Robert mistreated her, there is little need for you to think systematically about the good reasons Robert might have had. The mere fact that your friend has made a judgment affects your own intuitions directly . . .” (p. 820). So people’s intuitions are affected directly, not by any moral reasons espoused, but simply by who the espouser is. (Incidentally, these findings occur across the board, except in one group. Guess which one? See the answer below.)
Disgust/repugnance is a particularly contagious emotion. Imagine being in a situation with your good friends, and you come across some activity at which all of your friends immediately express strong disgust. It would be enormously difficult for you to resist experiencing the same emotion. It is in this respect, I suspect, that disgust is much like laughter and yawning: it serves as a form of social glue, a deep-seated form of bonding selected for a very long time ago. I have no doubt that it is utterly pre- or non-rational, though: what one will feel “yuck” towards will either be indicative of a primal aversion to something related to what we ought to avoid ingesting (e.g., rotten foods, excrement), or a function of what others we trust express disgust towards. In neither case, though, should the reaction necessarily play any role in contributing to public policy discussions of specifically moral matters.
What’s worrisome about this view, though, is that it applies to moral verdicts generally. It’s not just disgust that’s at the root of our moral verdicts, after all; it’s also a variety of other emotions that drive moral deliberations, and deliberation generally. Indeed, this is one of the most important findings of neuropsychology these days. So I’m not sure what the lesson is that we should draw from all this. Should we simply not trust our moral verdicts, insofar as they are typically based on intuitions dependent either on the emotions we simply find ourselves having or on the emotional bonds we happen to have to certain others? Or should we simply accept that these are the ways in which our brains operate, this is what our moral verdicts amount to, and then exploit that knowledge in the public domain to achieve consensus on the moral conclusions we want (via, say, a kind of public rhetoric/propaganda)?
I suppose, then, that there are a number of issues I’d like to hear from you on, based on the preceding rambling diatribe. First, what role, if any, ought the “yuck factor” play in public (or even private) moral discourse? Second, is there a way to distinguish disgust/repugnance from the other emotions that clearly play a role in our moral verdicts? Third, what, if anything, should be done about the way in which emotions generally feed into our moral “deliberations” and verdicts? Fourth, what precisely are the ethical issues involved in the creation of chimeras? (Sorry if that last question sounds like a nonsequitur, despite being the general motivation for the post itself.)
Oh, and what group is the exception to Haidt’s descriptions? That’s right: philosophers. But before you pat yourself on the back as being part of the one group that gets things right, you might consider the alternative possibility that you’re instead just deeply flawed humans….