Intelligence measures

Following the Analogy Finding Task, participants completed a brief battery of intelligence measures. The Similarities and Vocabularies subscales of the Multidimensional Aptitude Battery-II (MAB-II; Jackson [55]) were used to obtain a preliminary a measure of verbal ability, including an estimated total Verbal IQ. The MAB-II subscales are closely modeled after those of the Wechsler Adult Intelligence Scales-Revised (WAIS-R; [56]). However, the MAB was designed specifically to enable automated and group administration [57]. The MAB has been validated as a suitable alternative to the WAIS-R for measurement of verbal or general abilities [58]. Performance on the Similarities and Vocabulary subtests are correlated with WAIS-R total Verbal IQ scores at .60 and .74 respectively [58]. Per the MAB-II manual, we calculated a prorated estimate of total verbal IQ from the subscales we administered [55].

A version of the redrawn Vandenberg and Kuse Mental Rotation Test (MRT; [53, 54]) was used to assess spatial ability. On each MRT trial, participants identified which, if any, of a set of complex figures was a rotated version of a probe figure [54]. Participants completed two timed sections of MRT trials. MRT performance is highly related to other overall and perceptual IQ measures [59, 60].