Or, Schwitzgebel is at it again. (I'm a couple weeks late on this.)
Schwitzgebel (henceforth, ES) doesn't say that ethics classes ought to be changing students' behavior. He's just asking whether there's any evidence that they do. Although there's little evidence one way or the other, he suggests there's likely little hope for an affirmative answer, given the apparently minimal impact of ethics classes even on students' attitudes.
I have many and mixed thoughts about all of this. Rather than trying to weave a narrative or argument, I'm just going to number them.
1. Is this really surprising? I've never taught an ethics class where changing the students' ethical behavior in a particular direction was an explicit (or even implicit) goal. True, in accord with the education goals of the courses, I want my students' behavior as thinkers and writers to improve and deepen, but that's more of an intellectual than an ethical goal, even if the two are related. (If they are related, the positive changes would not be detected by attitudes surveys. The instrument is too superficial to tell us anything about how students' thinking--that is, their process of thinking--about ethical issues has changed. A student could change her views for superficial reasons, or maintain a previously held belief for better reasons. ES's methodology has no depth.)
2. What about professional and applied ethics courses? Maybe ES should look at those kinds of classes and leave aside classes where the focus is theoretical and historical (perhaps with some "hot topics" added to the mix). But even in applied courses, focus is often given to complex ethical issues on which reasonable people might disagree.
3. ES's question might seem innocent, but it seems to implicitly affirm the idea that ethics classes should bring about ethical changes (improvements) in student behavior. Maybe that's not entirely fair to him. But my point is that asking the question, treating it like a good question to ask, would seem to affirm the misguided idea that ethics classes can and ought to be geared toward changing students' ethical behavior.
4. What kind of ethics class could--in a liberal society and as part of a liberal education--have that as a goal? What code of ethics would all the relevant professors affirm? If we stuck with things that all, or almost all, would agree upon, then I'm not sure what ethics classes would be teaching anything of much depth or interest: don't kill people for fun, don't steal just because you want something, don't plagiarize your homework.
5. Charitably, one could see ES as dealing with a version of the "can virtue be taught?" issue--or, is it taught in ethics classes? But if Aristotle was right, then ethics class has never been the place where we become better (more ethical) people. It happens in the world, not the classroom. And again, the connection between what we learn about ethics and ethical thinking in the classroom and how that translates into action in the world is not obviously something that can be assessed by attitudes surveys. (Would there be a useful way to compare changes in attitude and behavior in a service-learning course in contrast with a traditional classroom course? Only, it seems, if the content covered in the course were the same.)
6. No doubt, we want our classes in one way or another to help mold our students into better people--more informed, better critical thinkers, better communicators, better at doing rather mundane things that they need to know how to do in order to be successful in the workplace (like doing their work on time, speaking and writing clearly, behaving decently around others, even others with whom they might disagree)--but those are fairly common educational goals that have something to do with "ethics" in a very broad sense. But then ethics class is not the place where those kind of ethical goals are pursued. Does ethics have any specific goals? Well, of course, there's the content and the philosophical skills involved. One might say it's a problem if ethics classes are all "head" (or, reflection) and no "heart" (or, no action), but then we have to think back to Point 4 above. Is anyone exactly prepared to appoint ethics professors the priests of our culture who will set about telling students how they must live and granting them the authority to punish those who fail to follow the rules? (Are ethics professors ready to accept that role?)