I have written a long series of posts on Jonathan Haidt's evolutionary moral psychology. One of them can be found here, which includes links to some of the others. My series of posts on the Darwinian psychology of the incest taboo (here) has included some thoughts about how Haidt uses the disgust aroused in most people by incest to illustrate the priority of emotion over reason in our moral judgments.
I have generally agreed with Haidt, but recently I have become skeptical about his use of his widely discussed scenario of Julie and Mark as a sister and brother who engage in incest. He presents this as a "harmless-taboo story" that elicits disgust and thus moral condemnation in the minds of most people, even though they cannot give any good reasons for why this is wrong, which apparently shows how moral judgment arises from irrational emotions rather than good reasoning. When people are asked to give reasons to justify their disgust, they grope for reasons that they cannot defend when challenged. They are, Haidt says, morally dumbfounded--they are sure that incest is wrong but without being able to support this moral judgment with good reasons.
I no longer find this persuasive. And I see some evidence that Haidt himself has changed his mind about this, because his "moral foundations theory" seems to recognize moral disgust as possibly being a good reason for moral condemnation, and also because he seems to have moved away from a purely emotivist theory to a more rationalist theory that sees no sharp dichotomy between reason and emotion in moral judgment. Earlier, Haidt embraced what he interpreted as David Hume's emotivist theory of morality; but now he seems to be moving towards accepting a better interpretation of Hume as seeing moral judgment as arising from both emotion and reason. In this way, he is moving towards Charles Darwin's understanding of human moral evolution.
Here's Haidt's story:
"Julie and Mark, who are sister and brother, are traveling together in France. They are both on summer vacation from college. One night they are staying alone in a cabin near the beach. They decide that it would be interesting and fun if they tried making love. At the very least it would be a new experience for each of them. Julie is already taking birth control pills, but Mark uses a condom too, just to be safe. They both enjoy it, but they decide not to do it again. They keep that night as a special secret between them, which makes them feel even closer to each other. So what do you think about this? Was it wrong for them to have sex?" (Haidt 2012, 38)Originally, Haidt and his collaborators presented this story to 30 undergraduate students at the University of Virginia. 24 of the students said that Julie and Mark were wrong to do this. They were then asked why was this wrong. They struggled to give a reason, and when they did, the interviewer would challenge what they said. Haidt reports:
"Most people who hear the above story immediately say that it was wrong for the siblings to make love, and they then begin searching for reasons. They point out the dangers of inbreeding, only to remember that Julie and Mark used two forms of birth control. They argue that Julie and Mark will be hurt, perhaps emotionally, even though the story makes it clear that no harm befell them. Eventually, many people say something like, 'I don't know, I can't explain it, I just know it's wrong'" (Haidt 2001, 814).Notice what Haidt did here. First, he implicitly assumed that the best rational principle of moral judgment is "no harm." Then, he carefully wrote the scenario about Julie and Mark to exclude the possibility of harm from their incest--either the harm of inbreeding for their offspring or the emotional harm to their relationship as siblings. He could then tell the students that this harmless conduct could not be morally condemned and that condemning this conduct as disgusting is irrational because disgust is not a rational principle of moral judgment.
Some of Haidt's critics have challenged him on all these points (Jacobson 2012; May 2018; Royzman et al. 2015). Weren't the students who condemned Julie and Mark correct in thinking that sibling incest is likely to be harmful? Even if they could avoid pregnancy and the harm of inbreeding, isn't it implausible that they could avoid emotional harm to themselves. In his scenario, Haidt says that Julie and Mark thought making love would be "interesting and fun," and that they could keep it as a "special secret between them" that would make them "feel even closer to each other." But isn't that unrealistic? And isn't it likely that most of the students found Haidt's scenario unbelievable?
In fact, when Royzman and his colleagues conducted their own experiment in asking students to respond to Haidt's story of Julie and Mark, the students were allowed to express their disbelief in the claim that Julie and Mark could engage in incest without harm. Most of the students could not believe that sex between siblings could occur without some emotional harm to the siblings. In Haidt's experiment, he refused to accept this by forcing the students to agree with the stipulated claim in his scenario that Julie and Mark were not emotionally harmed by their incest.
Some of the 39 comments on my first post on incest (October 7, 2006) are pertinent to this question of how harmful sibling incest might be. The 6th comment is by someone who says that "my younger sister and I played together sexually from an early age, and persisted well into adulthood," and he describes this as "an outlet for our strong sexual drives around the onset of puberty." But I wonder whether this "sexual play" stopped short of full sexual intercourse. And even if some siblings can do this at an early age, at the onset of puberty, with little permanent harm, isn't this likely to be risky behavior?
The risk is indicated in the 9th comment, where a man writes about his incest with his younger sister:
"While our relationship was consensual, non-abusive and non-exploitive, it also exacted a heavy price. Not 15 minutes after making love for the first time, she and I were both overcome with intense feelings of guilt and shame. No one ever taught us to feel this way, we simply did. These feelings did not go away either, but persisted for years afterwards, creating problems in our relationship that have never been fully resolved. For a long time I considered what we did back then to be the worst thing I'd ever done. Even so that did not stop us. The ability of the human libido to suppress one's moral judgment is truly amazing. What finally ended our sexual relationship was my leaving home to go to college. When she joined me a year later we'd been separated long enough to break the cycle I guess. We've never done anything since then."What explains those "intense feelings of guilt and shame" that arose automatically without their ever having been taught to feel that way? Edward Westermarck elaborated Darwin's suggestion that if inbreeding between closely related kin increases the risk of deleterious physical and mental traits in offspring, then natural selection might have favored a natural disposition to acquire a aversion for sexual mating with those with whom one has been reared from an early age, which might then be expressed culturally as an incest taboo, so that the idea of incest arouses a sense of disgust. This disgust would be strongest for sex within the nuclear family--sex between parents and children and between siblings--and weaker for more distantly related kin. This "Westermarck effect" would arise even for sex between unrelated people who have been reared together from an early age. One famous example of this is that people who had been reared together as children in the Israeli kibbutzim did not marry one another as adults, because they felt like siblings.
If this is true, then the moral condemnation of incest will be both emotional and rational: there will be an emotional expression of disgust with incest that depends on a rational judgment of what constitutes incest. Consider, for example, how Haidt's students might have responded to a scenario in which Julie and Mark were cousins who fell in love. Many of the students might have felt no disgust if they thought that sex between cousins need not be considered incest. Or if they were told that Julie and Mark were stepsiblings who had been reared in different families, this also might have led some of them to conclude that this was not incest. Or what if they were told that Mark's wife had died, and Julie was his sister-in-law? Here our moral emotion of disgust depends on our cognitive judgment of what counts as incest.
This illustrates how we reason with our emotions: we argue ourselves into and out of our moral emotions by judging whether those emotions are a justified response to the circumstances. Not many years ago, most people might have felt a disgust with interracial marriage and homosexual marriage comparable to their disgust with incest. But now this reaction has been weakened by the judgment that there is no harm in such marriages. Legislators and judges must debate these questions in deciding what kinds of marriage are permitted.
Although originally Haidt interpreted the moral disgust with incest as illustrating the purely emotive character of moral judgment, in which reason does nothing but fabricate rationalizations for what has been dictated by moral emotion, he has seemed to move in recent years towards recognizing the interaction of reason and emotion in moral judgment. He speaks of the "useless dichotomy between cognition and emotion," and he says that "emotions are not dumb," because "emotions are a kind of information processing," and therefore emotion and reasoning are two forms of cognition (2012, 44-48).
Here is his "social intuitionist model":
"One of the most common criticisms of the social intuitionist model from philosophers [like Joshua Greene] is that links 5 and 6, which I show as dotted lines, might in fact be much more frequent in daily life than I assert. . . . Of course people change their minds on moral issues, but I suspect that in most cases the cause of change was a new intuitively compelling experience (link 1), such as seeing a sonogram of a fetus, or an intuitively compelling argument made by another person (link 3). I also suspect that philosophers are able to override their initial intuitions more easily than can ordinary folk" (2012, 329).Notice, however, that Haidt does not explain the unnumbered arrow from "Eliciting Situation" to "A's Intuition." Surely, a situation cannot "elicit" my intuition unless I cognitively interpret that situation, which requires some kind of reasoning, even if the reasoning is quick, unconscious, and implicit rather than consciously deliberate. So when Haidt's students read his scenario about Julie and Mark, the students had to engage in some reasoning to decide whether the claim that their incestuous liaison could be harmless was realistic or not. Most of them decided that this was not realistic, and as a consequence of this rational judgment, their interpretation of this "Eliciting Situation" produced an intuitive emotion of disgust.
This is Hume's position. When Hume famously declares that "reason is, and ought to be the slave of the passions" (1888, 415), Haidt and others assume that he is promoting emotivist irrationalism or sentimentalism. But as the context of this remark makes clear, Hume believes that reason can direct action but not motivate it: "The impulse arises not from reason, but is only directed by it" (1888, 414). When our passions area accompanied by false judgments, reason can properly correct them. So, for example, reason might correct our false judgments that interracial marriage or the marriage of cousins is harmful and thus allay our moral disgust. As Hume says, "The moment we perceive the falsehood of any supposition, or the insufficiency of any means our passions yield to our reason" (1888, 416). "Reason and judgment may, indeed, be the mediate cause of an action, by prompting, or by directing a passion" (1888, 462).
Consequently, Hume contends, "reason and sentiment concur in almost all moral determinations and conclusions" (1902, 172). For example, reason might instruct us as to how justice could be useful for society, but this alone would not produce any moral approbation for justice unless we felt a sentiment of concern for the happiness of society (1902, 285-87).
Our concern for social happiness might promote the principle of no harm as one foundation for morality, which would apply to our moral judgments about incest. And if Haidt is right, the principle of not harming others is only one of at least six moral foundations--the other five being "liberty/oppression," "fairness/cheating," "loyalty/betrayal," "authority/subversion," and "sanctity/degradation." All six of these principles can be explained as intuitive or instinctive propensities of human nature as shaped by Darwinian evolution, and thus as moral universals across all of human history and across all human cultures. But the different rankings of those six principles constitute differing moral matrices. So Haidt has found that the moral matrix for American liberals ranks care for the victims of oppression as higher than the other principles, while American social conservatives elevate the principles of loyalty, authority, and sanctity, and American libertarians rank liberty as the highest principle.
Each of these six principles is a good reason for a moral judgment expressed through a moral emotion. And thus the debates between liberals, conservatives, and libertarians will be both rational and emotional as they argue over the proper ranking of those principles as applied to particular moral issues such as the legal regulation of sex, marriage, and family life.
Haidt has claimed that his research shows that "social conservatives have the broadest set of moral concerns, valuing all six foundations relatively equally" (2012, 306), which has provoked criticism from some liberal social psychologists. Haidt has criticized his colleagues in social psychology for having a bias against conservatives and libertarians in their field, In some of my posts, I have argued that Haidt's research actually supports a Darwinian conservatism that combines classical liberalism and traditionalist conservatism.
Haidt, Jonathan. 2001. "The Emotional Dog and Its Rational Tail: A Social Intuitionist Approach to Moral Judgment." Psychological Review 108:814-34.
Haidt, Jonathan. 2012. The Righteous Mind: Why Good People Are Divided by Politics and Religion. New York: Pantheon Books.
Hume, David. 1888. A Treatise of Human Nature. Ed. L. A. Selby-Bigge. Oxford: Oxford University Press.
Hume, David. 1902. Enquiries Concerning the Human Understanding and Concerning the Principles of Morals. 2nd ed. Oxford: Clarendon Press.
Jacobson, Daniel. 2012. "Moral Dumbfounding and Moral Stupefaction." In Oxford Studies in Normative Ethics, ed. Mark Timmons, 289-315. Oxford: Oxford University Press.
May, Joshua. 2018. Regard for Reason in the Moral Mind. Oxford: Oxford University Press.
Royzman, Edward B., Kwanwoo Kim, and Robert F. Leeman. 2015. "The Curious Tale of Julie and Mark: Unraveling the Moral Dumbfounding Effect." Judgment and Decision Making 10:296-313.