The persuasive power of knowledge: Testing the confidence heuristic

Area of Science:

• Cognitive Psychology
• Social Psychology
• Decision Science

Background:

• The confidence heuristic links knowledge to confidence and persuasion.
• Previous research focused on confidence-persuasiveness, not the full knowledge-confidence-persuasiveness hypothesis.
• The integrated hypothesis remains under-tested.

Purpose of the Study:

• To test the integrated knowledge-confidence-persuasiveness hypothesis of the confidence heuristic.
• To examine the heuristic's effect across different stimuli and communication methods.
• To determine if verbal or nonverbal communication is the primary driver.

Main Methods:

• Three experiments used incentivized interactive decisions with financial outcomes.
• Pairs with common interests conferred to identify target stimuli.
• One member per pair possessed strong information; tasks included facial identification and geometric shapes.
• Experiment 3 compared face-to-face and computer-mediated communication.

Main Results:

• All experiments confirmed the confidence heuristic.
• Geometric shapes elicited a larger confidence heuristic effect than facial stimuli.
• Similar effects were observed in both face-to-face and computer-mediated communication.
• Suggesting an answer first, often by informed members, appeared persuasive.

Conclusions:

• The confidence heuristic is robust across different stimuli and communication channels.
• Verbal communication appears to be the dominant driver of the heuristic.
• The findings support the integrated knowledge-confidence-persuasiveness hypothesis.