Information Source, Sequential Revision of Belief, and the Order Effect

The sequential revision of beliefs gives rise to a phenomenon referred to as the order effect due to two heuristics, anchoring and adjustment and contrast and inertia, as decision makers strive to incorporate confirming and disconfirming evidence. We hypothesized that the sources of new information would impact the order-effect. Results showed that confirming information from intelligence officers (experts) had a stronger effect on belief adjustment than information from a trusted friend, whereas disconfirming information from a trustworthy friend had a stronger impact than information from intelligence officers. A rationale for the differential effect of information source is discussed.