Journal of the Association for Information Systems


This study examines overconfidence in phishing email detection. Researchers believe that overconfidence (i.e., where one’s judgmental confidence exceeds one’s actual performance in decision making) can lead to one’s adopting risky behavior in uncertain situations. This study focuses on what leads to overconfidence in phishing detection. We performed a survey experiment with 600 subjects to collect empirical data for the study. In the experiment, each subject judged a set of randomly selected phishing emails and authentic business emails. Specifically, we examined two metrics of overconfidence (i.e., overprecision and overestimation). Results show that cognitive effort decreased overconfidence, while variability in attention allocation, dispositional optimism, and familiarity with the business entities in the emails all increased overconfidence in phishing email detection. The effect of perceived self-efficacy of detecting phishing emails on overconfidence was marginal. In addition, all confidence beliefs poorly predicted detection accuracy and poorly explained its variance, which highlights the issue of relying on them to guide one’s behavior in detecting phishing. We discuss mechanisms to reduce overconfidence.