Even highly educated young people who have grown up and been educated in Denmark risk being underestimated when their IQ is tested. New research points to hidden cultural bias in one of the most widely used intelligence tests.
When psychologists in Denmark test intelligence, the Wechsler Adult Intelligence Scale (WAIS) is often the tool of choice. The test is used in everything from clinical and educational settings to forensic psychiatry and social services. But according to a new study from the University of Copenhagen, the test can paint a skewed picture of the abilities of bilingual individuals - even when they speak fluent Danish and have completed their entire education in this country.
Tested on a level playing field - yet lower scores
The researchers tested 48 Arabic-Danish bilingual university students, the vast majority of whom were born and raised in Denmark and use Danish as their primary everyday language. All have completed their entire schooling within the Danish education system and have high school grade point averages above the national average.
Nevertheless, the participants performed significantly worse than expected on several parts of the WAIS test. Only the subtests for processing speed were at the level typically seen among Danes of the same age with a similar education, whilst linguistic and visuospatial (interpretation of visual information) tasks in particular dragged down the overall IQ score.
'Our participants are young people who perform very well academically. It is therefore highly unlikely that their lower test results reflect lower intelligence. Instead, this suggests that the test does not measure equally fairly across cultural and linguistic backgrounds,' says Ro J. Robotham, neuropsychologist and associate professor at the Department of Psychology, University of Copenhagen.
Culture plays a role - even in 'culture-free' tasks
According to the researchers, the results are linked to both linguistic factors and the degree of cultural orientation towards Danish mainstream culture on the one hand and their heritage culture on the other - even though the participants are fluent in Danish and have completed their entire schooling in Denmark.
Participants: The study is based on tests of 48 Arabic-Danish bilingual university students aged 19-42. Most were born and raised in Denmark, all have completed their entire school education here and speak fluent Danish. The participants are academically strong and have, on average, a high school grade point average that is above the national average.
The result: Despite their academic level, the participants scored lower than expected on the majority of the subtests in the Danish version of the WAIS-IV, which is the most widely used intelligence test in Denmark. The participants' language skills, as well as their orientation towards Danish culture and their heritage culture respectively, could explain a large proportion of the variation in performance on the intelligence test. This suggests that the test is not a pure measures of intelligence but is highly affected by a participants' language skills and cultural affiliation.
Conclusion: The WAIS-IV may underestimate intelligence in bilingual individuals - even when they are fluent in Danish and educated within the Danish school system. This points to a hidden cultural and linguistic bias in the test, which could have serious consequences if the results are used uncritically in clinical, educational or legal contexts.
A particularly striking finding is that the participants performed worst in the 'Block design subtest, which is often regarded as relatively culture neutral. However, this particular subtest turned out to be closely linked to how strongly the participants were oriented towards their heritage culture.
'Tasks such as working with blocks and visual patterns may be more culturally conditioned than many assume. These skills are shaped not only at school, but also through play, leisure activities and the environment in which one grows up,' explains co-author Thomas Rune Nielsen, associate professor at the Department of Psychology.
This means that even tests without words can favour people who have grown up with specific cultural experiences.
Can have serious consequences
According to the researchers, the results are not merely of academic interest. Intelligence tests are often used as the basis for decisions regarding educational opportunities, support measures and even legal rulings.
The study shows suggests that we may be underestimating IQ in this group by 10 points, which can be enough for a person to be incorrectly placed in a completely different category - for example, from 'low average' to 'intellectual disability'.
'Psychologists should therefore be very cautious when interpreting the overall IQ score of bilingual individuals, even if they have grown up in Denmark. The results must always be considered in the context of linguistic and cultural background,' says Ro J. Robotham.
The researchers emphasise that intelligence tests are important tools for psychologists.
'They ensure that assessments are not purely subjective. When used with the necessary caveats, they can help reduce bias in the assessments. But as psychologists, we must have the knowledge and necessary skills to take the client's cultural and linguistic background into account when interpreting test results,' points out Ro J. Robotham.
She adds that the University of Copenhagen is already working on strengthening competencies and skills in cross-cultural testing.
The study 'WAIS-IV performance in fluent Danish-speaking Arabic-Danish bilingual university students: Effects of acculturation and bilingualism' has been published in the scientific journal 'Journal of the International Neuropsychological Society'. It can be read here.
