Highlighting Effect: The Function of Rebuttals in Written Argument.

A rebutting counterargument is considered a very effective strategy to make one’s own argument more persuasive; however, the possible reasons behind this are not clear. In this study, we investigated the effects of rebutting counterarguments on persuasiveness in written arguments. One hundred undergraduate students were assigned randomly to two conditions: a “non-rebuttal condition” and a “rebuttal condition.” The participants in the non-rebuttal condition read written arguments that included three my-side reasons, and those in the rebuttal condition read written arguments with my-side reason, a counterargument, and a rebuttal. To determine the persuasiveness of the rebuttals in the written arguments, we investigated three points: 1) reader’s direct evaluations toward counterarguments and rebuttals, 2) how the contents of arguments last in readers’ minds, and 3) the relations between the first two points. As a result, we found that the participants in the rebuttal condition perceived counterarguments (other-side information) themselves to be needless, so the act of rebutting them was important for them and evaluated as being persuasive. Moreover, the participants in the rebuttal condition remembered my-side reasons better than the non-rebuttal condition. These results suggest that rebuttal has the function of “highlighting” my-side reasons.