The effect of massed versus spaced arguments on persuasion

UnrestrictedA manipulation of persuasive messages was explored to see what would result in more attitude change, such that two formats of presenting a series of arguments were used: massed and spaced. In massed presentation, five arguments were presented at once, and thought about all at the same time; in spaced presentation, the same five arguments were presented one-at-a-time, and thought about one-at-a-time. In the first experiment, control factors were used to account for confounding explanations, and spaced presentation resulted in more attitude change, regardless of the control conditions. The second experiment used two different argument sets, and found that spaced presentation was more effective than massed regardless of the argument set. A mediational analysis partially supported a cognitive response mediation explanation for the original set of arguments, but not for the alternate set. A third experiment showed that a distraction manipulation did not moderate the massed versus spaced effect, counter to the cognitive response explanation. A fourth experiment failed to moderate the effect with a set of counterarguing instructions, also inconsistent with the cognitive response explanation, but the effectiveness of the manipulation was questionable. A fifth experiment used a set of instructions to ensure serial order consideration of massed arguments, and the result failed to replicate. Overall, the results most support the idea that the robust massed versus spaced effect does not depend on elaboration of message content, but instead is a low-effort heuristic where people feel like they have considered more information, and thus their attitudes change more. Future experiments will need to follow up on this possibility to confirm the explanation for the effect