Objective personality tests were developed for two aspects of intolerance of ambiguity: (a) the tendency to reach perceptual closure quickly and (b) the tendency to jump to generalizations on the basis of specific information. The two tests utilized a tab format which enabled the subject either to respond immediately to an item or to request more information, as he chose. The reliability of the personality score on one test was .91, and on the other, with only half as many items, .64. Corrected reliabilities, with various ability control measures regressed out, indicated that only a small part of this reliable variance could be accounted for by content ability. The two scores were significantly correlated (.34), and the coefficient tended to increase slightly upon partialling out various control measures. This significant correlation contributes to the construct validity of intolerance of ambiguity, but it was also pointed out that the concept of "cautiousness" presents an alternative rationale for the test procedures and is consistent with the obtained results.