Neuropsychological assessment in linguistically heterogeneous populations is fraught with numerous challenges, such as lacking or inappropriate normative data or the unavailability of appropriate tests. Accommodating multilingual individuals exacerbates the issue by adding the question of which language(s) to use when assessing multilingual individuals. Different testrelated concepts may be accessible to them via different languages, as their lexicon is spread out over two or more languages. Hence, any monolingual instrument is likely to disadvantage them. The present set of three studies circumvents this question and presents evidence for an inherently multilingual English/Afrikaans/isiXhosa screening tool for intelligence, the Multilingual Vocabulary Test (MVT). I describe the instrument’s development from the pilot study to a psychometric analysis of the final, digitally administered version. For an abbreviated 13-item version, Study 3 (N = 494) shows an internal consistency of  = .59 and Study 2 (N = 101) produced significant criterion-related validity values of r = .46 and r = .52 with the KBIT-2 and Shipley-2 VIQ scores respectively. Linear regression analyses show that, while all criterion measures are biased toward E1-speakers, the MVT is largely immune to test-takers’ linguistic background. Thus, the MVT paves the way toward more fairness in cognitive assessments, in general, and provides a promising first step toward addressing one of South African neuropsychologists’ greatest needs—that of a quick and easy-to-administer, yet linguistically fair screening tool for cognitive impairment.

Objective: Cultural neuropsychologists face barriers such as access to culturally appropriate psychometric instruments and norms. Further, three commonly encountered dilemmas in cultural neuropsychology include the following questions: (1) How do psychologists determine the best normative data to use for a given assessment scenario? (2) Do measures and models developed with North American samples also work in adaptations of instruments used with cross-cultural samples? (3) How can alternative and cost-effective measures be developed to meet the need for additional assessment tools? In response to these dilemmas, this dissertation consists of three papers aimed at developing Latinx and cultural neuropsychology psychometric resources for one of the most common cultural assessment scenarios: intelligence assessment amongst Spanish-speaking individuals using the Wechsler Adult Intelligence Scale – Fourth Edition (WAIS-IV). Chapter 1. A sample of 305 highly educated Colombian corporate executives completed the WAIS-IV. Data were scored using norms from Colombia, Chile, Mexico, Spain, United States, and Canada and scores were compared using ANOVA. Additionally, a comparative sociodemographic framework was established to contextualize our sample to the standardization samples and populations of the six countries. Chapter 2. Accumulating evidence indicates the original factor structures published in the Wechsler Intelligence Scales may not best describe the data captured by these tests, and instead supports a five factor Cattell-Horn-Carroll (CHC) model over a four factor Wechsler model, and a bifactor model over a higher-order model. Confirmatory factor analysis and structural equation modeling was used to evaluate factor structure of the Chilean-WAIS-IV (Wechsler, 2013) normative sample (ages 18-60; N=672) to better understand its psychometrics and to contribute to much needed cross-cultural study of alternative WAIS-IV factor models. Results marginally favored CHC and bifactor models but provided strong support for higher-order and Wechsler model variants as well, pointing to the need of further theoretical, methodological, clinical, and cross-cultural research. Chapter 3. The recent publication of the Chilean adaptation of the WAIS-IV has contributed to ongoing efforts to provide more psychometric instruments culturally appropriate for regions in South America. While not all assessment situations necessitate administration of the full WAIS and calculation of a full-scale intelligence quotient (FSIQ), there is virtually no published research on WAIS-IV short forms for estimating IQ in Latin America. This study used a rigorous series of methods (adapted from Smith et al., 2000) to develop robust estimated IQ short forms, aligned with Wechsler and CHC models, using the Chilean WAIS-IV standardization data (ages 18-90; N=887). Linear scaling was used to produce normative tables for the 28 best two-, three-, four-, and five subtest short forms of the Chilean WAIS-IV. Discussion. Together, the three papers of this dissertation provide psychometric guidance and resources not only for Latin American neuropsychologists in the area of intelligence assessment, but also more broadly for all cultural neuropsychology researchers and clinicians. / Graduate / 2020-06-25