Study: Chocolate Betters Course Ratings

Chocolate is a legendary aphrodisiac, but can it make you love a class?

External factors, even something as small as a candy bar, can influence student responses on course evaluations, according to a study by two social psychologists.

Students in one discussion section were offered chocolate before filling out teaching evaluations, while those in another section completed the evaluations without the candy.

Of the 98 students in three lecture classes, those offered chocolate gave responses that were on average approximately 4 percent more positive, even though the sections were taught by the same teaching assistant.

“Based on our results, I think it’s really unfair if instructors are compared against one another where some have been impacted by these [factors],” said one of the study’s authors Benjamin D. Jee, now a post-doctoral fellow at Northwestern University.

Students in the experiment were told that the chocolate was left over from an earlier event, so that they would not think it was in any way associated with their professor or teaching assistant.

“People think that their judgments are sacred,” said the study’s other author, Robert J. Youmans, now an assistant professor at California State University Northridge. “In fact, they are privy to being pushed around a lot, by a lot of things, including things that have nothing to do with what you’re judging.”

Jee and Youmans were PhD candidates at the University of Illinois’ Chicago campus in 2006, when they conducted their research.

Professor of Psychology Ellen J. Langer, who specializes in the pyschology of control, aging, and decision-making, agreed.

“Positive experiences lead to positive sentiments,” she said yesterday afternoon.

Jee added that similar results were likely to occur if students were given a negative external stimulus—such as a bad exam grade—before completing an evaluation.

The pair said they became interested in the accuracy of evaluations during their own reviews. They chose chocolate for the study because they had noticed that distributing treats around evaluation time was a fairly common practice among professors and teaching fellows.

Not all students, however, are convinced of chocolate’s power. Jessica L. Flakne ’11 said over the weekend that she was skeptical about the power of food to sway student opinion.

“They probably won’t win too many brownie points with me just by bringing in baked goods,” she said.

The study, entitled “Fudging the Numbers: Distributing Chocolate Influences Student Evaluations of an Undergraduate Course,” will be published by the journal Teaching of Psychology later this month.