Do college philosophy courses in ethics affect the real-world choices of the students who take them? A trio of philosophers recently took up this question and have just published their results.Eric Schwitzgebel (UC Riverside), Brad Cokelet (Kansas), and Peter Singer (Princeton) conducted a controlled study of over 1,000 students that involved exposing about half of them to a lesson and teaching materials on the ethics of eating meat, having them complete a questionniare, and then monitoring their food purchases.
As far as we are aware, this is the first controlled study to show an effect of university-level ethics instruction, as conducted in ordinary philosophy classes, on non-laboratory behavior, using direct observational data rather than self-report. We found that after exposure to a philosophy article, a fifty-minute philosophy discussion section, and an optional online video concerning the ethics of eating factory farmed meat, students decreased their rates of meat purchasing from 52% to 45% of their food purchases of $4.99 or more in campus dining loca-tions for which receipts were available, compared to a constant rate of 52% among students in a control group exposed to similar materials on the ethics of charitable giving. This effect appears to have been a widespread moderate reduction of meat purchases among students ra-ther than the conversion of several students to strict vegetarianism. Although we had only limited ability to detect the time course of the effect, we did not observe a decrease in effect size among students for whom we had several weeks or several months of data. The effect size is in our judgment striking given the brevity of the intervention and the fact that most university students are likely to have been previously exposed to arguments for and against vegetarianism.
Expressed moral opinion also changed substantially. In the ethics of charity control condition, 29% of participants agreed that “eating the meat of factory farmed animals is unethical”, compared to 43% in the ethics of eating meat condition.
In an email, Professor Singer wrote:
It’s worth noting that the lead author, Eric Schwitzgebel, is best known for his previous research showing that professors who work in ethics do not act more ethically than other professors This finding led him to doubt that we would get a positive result in this study. But like a good philosopher-scientist, he wanted to test his views against the evidence.
After teaching practical ethics for my entire career, I would have been disappointed if we had failed to get a positive result, but I too believe that we need to check our views against the evidence. I’m glad that we now have the evidence to show that we are making a difference.
You can read the study, published in the journal Cognition, here.