Criterion-related validity, self-other agreement, and longitudinal analyses for the Iowa personality questionnaire: A short alternative to the MPQ

The 42-item Iowa Personality Questionnaire (IPQ) was designed to briefly assess the same dimensions of personality measured by the Multidimensional Personality Questionnaire (MPQ; Tellegen, 1982). Results from three studies indicate that the IPQ can be used as a reasonable alternative to the MPQ when time constraints place limits on the length of questionnaires. For example, correlations between self-reports on the IPQ and the MPQ were .67 for Constraint, .75 for Negative Emotionality, and .77 for Positive Emotionality and the IPQ and MPQ demonstrate similar criterion-related validity (Study 1). Importantly, Study 3 illustrates how the IPQ can be used to address the substantive issue of the rank-order consistency of personality traits across time. Specifically, longitudinal results indicated that scores on the MPQ assessed in 1994 forecast scores on the IPQ in 2001. These findings provide further evidence for the continuity of individual differences across time.