A Procedure for Estimating Intrasubject Behavior Consistency

Trait psychology implicitly assumes consistency of the personal traits. Mischel, however, argued against the idea of a general consistency of human beings. The present article aims to design a statistical procedure based on an adaptation of the pi* statistic to measure the degree of intraindividual consistency independently of the measure used. Three studies were carried out for testing the suitability of the pi* statistic and the proportion of subjects who act consistently. Results have shown the appropriateness of the statistic proposed and that the percentage of consistent individuals depends on whether test items can be assumed as equivalents and the number of response alternatives they contained. The results suggest that the percentage of consistent subjects is far from 100%, and this percentage decreases when items are equivalent. Moreover, the greater the number of response options, the lesser the percentage of consistent individuals. (Contains 2 figures and 5 tables.)