Is It Still Working? Task Difficulty Promotes a Rapid Wear-Off Bias in Judgments of Pharmacological Products

Misuse of pharmacological products is a major public health concern. Seven studies provide evidence of a rapid wear-off bias in judgments of pharmacological products: consumers infer that duration of product efficacy is dependent on concurrent task difficulty, such that relatively more difficult tasks lead to faster product wear-off. This bias appears to be grounded in consumers' incorrect application of a mental model about substance wear-off based on their experiences with, and beliefs about, various physical and biological phenomena. Results indicate that the rapid wear-off bias affects consumption frequency and may thus contribute to overdosing of widely available pharmacological products. Further, manufacturers' intake instructions in an interval format (e.g., "Take one pill every 2-4 hours") are shown to signal that efficacy is task dependent and reinforce the bias. Debiasing mechanisms--interventions to reduce the rapid wear-off bias and its impact--along with implications for consumers, marketers, and public health officials, are discussed.