WAIS-IV performance of working-age Polish people in the UK

Objectives: Clinical neuropsychologists are increasingly called upon to undertake cognitive assessment of clients who have English as an additional language. We sought to investigate how linguistic disadvantage affected performance on a widely-used cognitive test.
Design: A cross-sectional, between groups study, in which UK residents with English as an additional language were examined on the WAIS-IV in English. Scores were compared to those of a primary English-speaking group, matched for sex, age, and years of education.
Methods: 100 working-age Polish participants, males and females, from a range of educational and SES groups, were recruited from London and nearby areas, and individually examined on the 10 core WAIS-IV-UK subtests. Individuals’ scores were compared to the manual norms to derive subtest age-scaled scores and the main indices. A control group of 100 primary English speakers (individually matched to the Polish participants on sex, age, and years of education) was taken from the UK standardization sample. Group means were compared, along with item-level inspection for bias.
Results: The Polish group were disadvantaged mainly on verbal tasks, but this affected their scores on tests of working memory. Measures of processing speed and visual functions were less affected; though differences emerged on tests widely considered culture-fair. In some cases, the Polish sample outperformed the UK controls. These differences should be borne in mind when interpreting individual test performances.