Publication Date


Degree Program

Department of Psychology

Degree Type

Master of Arts


Recent studies have reported different findings about how moral judgment as defined by the Defining Issues Test (DIT; Rest, Narvaez, Bebeau, & Thoma, 1999) relates to verbal intellectual ability. For example, Sanders, Lubinski, and Benbow (1995) argued that DIT scores are reducible to indices that represent verbal intellectual ability. Thoma and his colleagues (Derryberry, Thoma, Narvaez, & Rest, 2000; Thoma, Derryberry, & Narvaez, 2003; Thoma, Narvaez, Rest, & Derryberry, 1999) found support that DIT scores and indices of verbal intellectual ability are separate sources of information. In considering this relationship, these previous studies have most often referred to grade point average (GPA), American College Test (ACT), and Scholastic Aptitude Test (SAT) scores in describing verbal intellectual ability. As such, this research has been vague in defining what is meant by verbal intellectual ability. The present study recognizes Cattell and Horn's (1978) conception of crystallized intelligence as similar to the construct that the aforementioned research has considered. Therefore, the present study was designed to gain a better understanding about the nature of DIT scores in considering how they relate to an actual assessment of crystallized intelligence. For the current study, 117 participants provided complete data across two sessions. In the first session, participants were given the DIT and the Attitudes toward Human Rights Inventory (ATHRI; Getz, 1985). In the second session, participants were assessed using the Kaufman Adolescent and Adult Intelligence Test (KAIT; Kaufman & Kaufman, 1993). Results support the idea that DIT and KAIT scores are separate sources of information and influence ATHRI scores differently. Results also show that crystallized intelligence scores contribute to moral judgment scores though there is much variance that is unshared between these two constructs. Thus, the present study affirms the construct validity of the DIT but points to a role for crystallized intelligence in the measurement of moral judgment. Based on the evidence from the current study, there is evidence that upholds an important approach to measuring moral judgment development. Furthermore, there is little evidence supporting queries (e.g., Lykken, 1991) that have maintained that measurements of popular psychological constructs are the product of intellectual ability.


Cognition and Perception | Psychology