Behavioral expressions of intolerance of uncertainty in worry. Experimental findings.

Intolerance of uncertainty has been related to increased worry in recent conceptual models of Generalized Anxiety Disorder (GAD). The present study examines the relationship between a measure of intolerance of uncertainty, the Intolerance of Uncertainty scale (IU), and behaviors associated with GAD, such as slowness of execution and amount of evidence required before decision making. A total of 49 individuals participated in the study. Three experimental tasks varying in level of ambiguity and difficulty were used. The analyses show a positive correlation between scores on the IU and number of cues required before responding in a moderately ambiguous inference task. However, scores on the IU were not significantly related to responses in an unambiguous task (regardless of the level of difficulty) or in a highly ambiguous task. The results suggest that high worriers have a lower threshold of tolerance of uncertainty for intermediate levels of ambiguity. The results are discussed in terms of theoretical models of GAD.