Individual differences in decision-making

The study of individual differences in rational decision-making has led to two close streams of research. While the study of scores to the Adult-Decision Making Competence (A-DMC) tasks has provided evidence in favor of a general decision-making competence (DMC) factor, studies investigating individual differences in performance on heuristics and biases tasks have challenged a one-factor model of rationality. Assuming that heuristics and biases are part of DMC and considering that the A-DMC assesses just a few of them, the aim of the present study was to test whether a general DMC factor still emerges when adding four heuristics and biases tasks to the six A-DMC tasks, while ensuring satisfactory levels of score reliability. Exploratory factor analyses revealed that while performance on the A-DMC tasks can be reasonably aggregated into a general DMC measure, a two-factor model provided the best statistical and conceptual fit of the 10 tasks combined, the two factors reflecting Mindware gaps and Contaminated mindware.