Jumping to conclusions in the less-delusion-prone? Preliminary evidence from a more reliable beads task.

BACKGROUND AND OBJECTIVES

Several meta-analyses have shown that people with psychosis tend to gather less information (i.e., they make fewer draws to decision, or DTD) on the beads task than healthy controls. A single meta-analysis has also found a small negative association between delusion-proneness and DTD in healthy samples, but with considerable heterogeneity.

METHODS

We used the new and more reliable "distractor sequences" beads task to clarify the nature of the relationship between delusion-proneness and DTD in a healthy sample. Healthy participants (N = 203) completed the distractor sequences beads task and the Peters Delusions Inventory (PDI), which measures delusion-proneness.

RESULTS

PDI and DTD were positively correlated, and those who jumped to conclusions (DTD ≤ 2) had lower PDI than those who did not. Comparing PDI quartiles on DTD provided some evidence the positive association did not extend to the highest PDI quartile. We found that DTD and delusion-proneness were positively related in our non-clinical sample, which was unexpected.

LIMITATIONS

Results need replication with a clinical sample.

CONCLUSIONS

Considering the well-established association between the JTC bias and clinical delusions, the current finding may reflect a relationship that differs between non-clinical and clinically significant delusional groups, or one which reverses sign at some level of delusion-proneness.