Verbal intelligence in bilinguals when measured in L1 and L2

Area of Science:

• Psycholinguistics
• Cognitive Psychology
• Neuroscience

Background:

• Bilingualism impacts cognitive functions, including verbal intelligence.
• Understanding performance differences in dominant vs. non-dominant languages is crucial for accurate assessment.
• Previous research has not fully explored Verbal IQ differences in simultaneous versus early sequential bilinguals using standardized measures.

Purpose of the Study:

• To investigate and compare Verbal IQ scores in simultaneous and early sequential Spanish/English bilinguals.
• To determine if bilingual individuals are underestimated in cognitive assessments conducted in their dominant language.
• To analyze performance variations between English and Spanish language testing within these bilingual groups.

Main Methods:

• Recruited 48 Spanish/English bilinguals who moved to the U.S. before age 10.
• Administered the verbal subtests of the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) in both English and Spanish.
• Compared Verbal IQ scores between the two language tests and between simultaneous and early sequential bilingual groups.

Main Results:

• Both bilingual groups demonstrated significantly higher Verbal IQ scores when tested in English compared to Spanish.
• Simultaneous bilinguals showed a one standard deviation higher Verbal IQ in English; early sequential bilinguals showed a half standard deviation difference.
• Average English Verbal IQ scores were around 100, which is considered lower than expected for individuals with bachelor's degrees.

Conclusions:

• Bilingual individuals, including those tested in their dominant language, may face assessment challenges.
• The study highlights a potential underestimation of cognitive abilities in bilinguals due to language of testing.
• Further research is needed to explore the implications of these findings for educational and clinical settings.