Approaching and Avoiding Linda: Motor Signals Influence the Conjunction Fallacy

In two experiments, using two different conjunction problems, participants who engaged in avoidance motor actions were significantly more likely to commit conjunction errors than participants who engaged either in approach or no motor actions. Because previous studies (e.g., Friedman & Förster, 2000) have demonstrated that avoidance motor signals enhance analytic processing, whereas approach motor signals enhance heuristic processing, these findings suggest that enhanced heuristic processing does not necessarily lead to an increase in conjunction error. Instead, detail-oriented processing can lead participants to pay too much attention to irrelevant details in a given narrative, which can undermine consistency with normative principles of judgment. (PsycINFO Database Record (c) 2007 APA, all rights reserved) (from the journal abstract)