There are a bunch of different ways to teach undergraduates about moral psychology in a philosophy department:

1. Emphasize free will issues: weakness of will, nature of addiction (& mental illness), causal role of environment and genetics, reactive attitudes and the nature of blame and praise, etc. Is akrasia even possible? Is Kant’s moral psychology plausible?
2. Emphasize the profession of psychology and the bifurcation of research and practice. How does therapy work? Is the DSM a useful guide to our psychic lives? Is mental illness a myth? Is the replication crisis a particular problem for psychology? Do forensic psychology and social work perpetuate white supremacy and mass incarceration?
3. Hortatory and didactic: how can you be a good person? Are personality traits persistent over time? If we are character skeptics should we be virtue skeptics? What should we do with all these feelings and negative emotions? How can we overcome implicit and explicit bias? Also can literary classics actually make us finely aware and richly responsible?
4. The specific psychology of evil and oppression: study bias, conformity, and the psychic forms of dehumanization, racism, sexism, and obedience to authority. Look at group membership as a primary source of the corrosion of morality. In a sense this is the liberal version of “how to be a good person” i.e. “how to be an anti-racist feminist,” “how to overcome our internalized misogyny and ableism,” etc. But a course like this is likely to focus on particular examples, take up issues closer to political psychology and moral foundation theory.
5. Emphasize epistemic issues: the same organ psychology studies is the organ doing the studying. We are deeply inconsistent and self-contradictory. We are tribal. We make excuses for ourselves while judging others mercilessly. We want things we can’t admit. We have implicit biases we explicitly deny. We engage in motivated reasoning. We don’t live up to our principles, making excuses for ourselves we disallow to others. We are vulnerable to situations and peer pressure. Altruism is itself egotistical. F.A.B.R.E.A.M.–fundamental attribution bias rules everything around me.
6. Focus on metaethics: what is personal identity? Is moral talk merely expressive boo/hurrah or is there a moral reality that our judgements can track or not? Do the psychological and motivational shortcomings of consequentialism render it a less plausible account of morality?
7. Focused on the developmental story: take the debate between Lawrence Kohlberg and Carol Gilligan as the central debate, and try to figure out what it means that people are so different from each other. How much of morality is mere culture? Is there anything we can say about individualism versus collectivism as focal points of Western versus Eastern cultures? Is there something wrong with all the psychological research done on college students from Western, educated, industrialized, rich democracies? What do we truly have in common?

I love all these different versions of the class and I’ve taught them all, and probably there are more I haven’t thought of. But I think moral psychology courses shine when they emphasize the good old fashioned “hermeneutics of suspicion” I name-checked in my title. What if we are strangers to ourselves? What if we know not what we do? What if we live under conditions of radical self-deception? What if evolutionary psychology or an understanding of the human archetypes captured in Sophoclean tragedy can show us our true motivations and debunk our fake ones?

Basically, we have easy phenomenological access to some parts of our own psyches, but we also have plenty of evidence that there’s “more to it” than what we can easily see about ourselves. We are uneasy inhabitants of our own heads, and there’s something interesting and provocative in that experience of self-estrangement.

In contrast with most of the straight-ahead moral philosophy out there, moral psychology tends to call our motivations into question. I quite like this Regina Rini paper on psychological debunking of moral judgments, but she casts this as an objectionable experience of disunity. I’d argue that our continued fascination with psychological debunking comes both because it provides a satisfying opportunity to debunk others (to see them better than they see themselves) and to explain the parts of our own experience that don’t quite make sense and hold out hope of greater unity.

For my money the notion of self-estrangement is the fundamental insight of psychology as a discipline separated out from philosophy. (I follow Anthony Appiah on this: the growth of philosophy as it’s understood today largely tracks the creation of independent departments of psychology.) It’s precisely because we can’t see ourselves clearly and we engage in elaborate justifications and deceptions that we can’t study the mind from the arm chair with introspection and meditation. We need at least two arm chairs for the talking cure, or rather we need the analyst’s couch, the psychiatrist’s prescription pad, the neuroscientist’s fMRI, and the social psychologist’s tricksy experiments. Ironically, we even need some bad developmental psychology so we can do better social psychological experiments: Milgram’s experiment famously works because we trick people into thinking they’re researching BF Skinner’s behaviorism but really they’re proving that most of us are Good Germans underneath it all.

Anyway, much is made of the standard moral error theory—that we simply don’t understand what our moral talk is really about, because moral states are not about anything at all. But I prefer the kind of error analysis you get from the “heuristics and biases” literature, which is also embedded in the Rawlsian notion of reflective equilibrium: if there’s nothing at all that our moral judgments are about, then it doesn’t make sense to say that our judgments are biased or wrong. But if they are clearly inconsistent with each other, then at least greater consistency is possible. The evidence from psychological studies of moral development and the experiment philosophy results about our moral behavior can all help us identify candidate moral intuitions or judgments upon which to train that search for consistency.

That’s through-line between Freud’s psychoanalysis and Haidt’s moral foundations theory: that we can learn things beyond “bubba psychology,” i.e. the psychology of wise old women who have observed many generations of people and have finely attuned and richly aware assessments of themselves and others. Yet at the same time, because psychologists (inhabiting the same buildings in universities and the same sections of the book store) both research the mind and provide specific clinical support to suffering individuals, there have been some key bubba psychology insights that required this rejection of common sense to make clear.

Both therapeutically and philosophically, then, there’s something like a set of deep and potentially clichéd lessons to learn from moral psychology here:

1. People are different. (There’s a lot more human variation than most people admit, and it’s not arranged in a clear hierarchy from bad to good or sick to healthy.)
2. Don’t believe your gut, it’s full of shit. (Your emotions are not so smart.)
3. Don’t believe everything your brain tells you, either. (Your rationality is really good at giving you the answers you want to hear.)
4. Pick your friends and associates carefully. (The history and the psychological research clearly show that if those groups are cruel, or racist, or genocidal, then we are likely to be cruel, racist, and genocidal too.)

Probably it is more complicated than this. Probably there are more. Families matter. Community matters. Institutions and incentives matter. The prevalence of conformity and social normativity, for instance, makes me think that “pick your friends and associates carefully” is maybe a bit more difficult to implement than I’ve made it sound here. There are contributing factors that seem to make the very notion of “picking” a misnomer, since it is rarely under our conscious and fully autonomous control to decide with whom we are going to spend our time. And thus if you’re doing psychology, pretty soon you need to start doing sociology, and economics, and anthropology, and political science too. It really requires a kind of interdisciplinary social scientific approach. Or maybe we just call it philosophy?