As IQ tests are commonly used as key assessment method, we address the question whether our commonly used standardized IQ tests are appropriate for children from families of diverse cultures and different educational levels in a refugee population. We examined 109 refugee children aged 3–7 years (M = 5.10 years, SD = 1.25) with the “Kaufman Assessment Battery for Children “ (KABC-II; Kaufmann & Kaufmann, 2015) on a language-free scale (Scale of Intellectual Functioning, SIF) and learning performance (subtest Atlantis). With a non-verbal IQ of 81.5 (SD = 18.01), the population mean of the refugee children is more than one standard deviation lower than the mean of the German norm population. Standardized scores follow the normal distribution and are not correlated to any of the assessed markers of adversity (flight duration, time spent in Germany, child PTSD in parent rating, parental symptom load, and parental education level). Conclusion: The interpretation of IQ test results for refugee children should be done cautiously as results may underestimate their cognitive capacity. Environmental factors, such as high illiteracy among parents in this study, the lack of institutional education of children and high lifetime stress, may explain our findings. Trial registration: DRKS00021150.What is Known:• There is a high pervasiveness for the use of standardized IQ tests in the German health and education system to determine eligibility for special education and social services.What is New:• Refugee children score significantly lower than German children in a language-free IQ test. As results are normally distributed and not correlated to any of the assessed markers of adversity, the low scores in the refugee group might be due to missing formal education.

DOI: 10.1007/s00431-021-04312-8
ISSN: 0340-6199