Disentangling language proficiency and acculturation in WAIS-IV performance among Spanish-English bilingual...

As the number of bilingual individuals in the United States grows, psychologists face challenges due to limited suitable measures and guidance for their administration and interpretation. This study examined the validity of college students' self-reported language proficiency and the influence of language and acculturation on performance on the Wechsler Adult Intelligence Scale, Fourth Edition. Participants were Spanish-English bilingual university students (N = 59, 86.44% female) from a Hispanic-serving institution who completed subjective and objective language assessments and the Wechsler Adult Intelligence Scale, Fourth Edition in English and Mexican Spanish across counterbalanced sessions. Most participants reported minimal differences between languages, but objective tests revealed that oral English skills often surpassed those in Spanish, with low to moderate correlations between self-assessments and objective scores. After controlling for stress and practice effects, significant differences appeared only on the Verbal Comprehension Index. Only objective language proficiency and preferred language predicted which language yielded better performance; acculturation explained no additional variance. We discuss clinical implications for using the Wechsler Adult Intelligence Scale, Fourth Edition with English-dominant bilingual college students and recommend that clinicians routinely evaluate language and social backgrounds, as objective language proficiency may guide assessment language decisions for bilingual individuals. (PsycInfo Database Record (c) 2026 APA, all rights reserved).