Motivated reasoning: A depth-of processing perspective

We show how motivation affects reasoning through reliance on a biased set of cognitive processes. We manipulate the level of brand preference experimentally and expose subjects to a message that is either consistent or inconsistent with their manipulated preference. Further, the message contains either strong or weak arguments. In two experiments, we find that preference-inconsistent information is processed more systematically and is counterargued more than preference-consistent information. In addition, experiment 2 shows that strong arguments are more persuasive than weak arguments in the preference-inconsistent condition. We employ the heuristic-systematic model of persuasion and its sufficiency principle as a framework to understand the psychological mechanism that underlies the biased processing of preference-inconsistent information.