The share of meal plan expenditures on meat by students who took part in a philosophy class on the ethics of eating animals declined from 52% to 45%, with “no evidence that meat-eating rates went back up during the two months data was monitored,” according to a recent study whose authors believe it provides evidence for the claim that “ethics classes can influence student behavior.”

The study, by Eric Schwitzgebel (UC Riverside), Brad Cokelet (University of Kansas), and Peter Singer (Princeton), was presented at the 2019 Meeting of the Society for Philosophy and Psychology.

“In the current environment where people are not reasoning so well, it is heartening to learn that rational thinking changes behavior,” said Cokelet, according to a press release from the University of Kansas. “A lot of psychologists have produced results saying most of us—most of the time—make our decisions based on emotion or gut instinct. Then after the fact, we rationalize what we’ve done. So reason is not in the driver’s seat. This is evidence reason can be in the driver’s seat for some people.”

The study design and methods are posted at Professor Schwitzgebel’s blog. It involved over 1100 UC Riverside students in four lower-level philosophy courses. Half the students prepared for and took part in a class session on the ethics of meat-eating, while the other half (the control group) did the same for a session on charitable giving.

The investigators then examined available campus dining card purchases data and saw the average decline in non-vegetarian purchases only among the students who took part in the session on eating meat. Further details here.