WISC-IV test performance of Grade 3 Xhosa-speaking children: An extension of a prior South African normative database.

Abstract

Introduction. A well-recognized problem exists when commonly employed tests developed in the United States (US) or United Kingdom (UK) are accepted unconditionally for use on local relatively disadvantaged populations, as these tests have questionable validity and therefore incur a high risk of misdiagnosis. Cross-cultural normative research has been conducted in South Africa on some of the Wechsler intelligence scales with respect to participants stratified for level and quality of education, age, race and language, including a study on the Wechsler Intelligence Scale for Children – Fourth Edition (WISC-IV) for learners with Grade 7 education (age 12 to 23). The aim of the current study was to conduct a partial duplication of the earlier WISC-IV South African norming study that specifically targeted a younger group of educationally disadvantaged children at a lower level of education. Method. Participants were Black Xhosa-speaking Grade 3 learners in the age range 8 to 9 (N =32 ), who were being schooled in the disadvantaged educational setting of the former Department of Education and Training (former-DET) schools. The WISC-IV results of the current study were statistically compared with the WISC-IV results from Shuttleworth-Edwards, Van der Merwe et al. (2013) study. Results. There was a significant lowering of between 20 to 30 IQ points relative to the UK standardisation on WISC-IV scores for this sample of Grade 3 Xhosa-speaking learners, replicating the earlier outcome for Grade 7 Xhosa-speaking learners relative to the UK standardisation. No differences were in evidence within the WISC-IV sample for the female and male participants on any of the indices. There was equivalence between the Grade 3 and Grade 7 Xhosa-speaking learners on all subtest and Index scores with the exception of the Digit Span subtest. Conclusions. The results confirm prior research indications of the negative impact of educational disadvantage on IQ test results and the need for this to be taken into account by the availability of socio-culturally relevant norms.