Fast mapping of verbs in Afrikaans-speaking children from low and mid socioeconomic backgrounds and children with language impairment

Children with LI are at a disadvantage because they typically have smaller vocabularies than their TD peers. However, children from low-SES households often also have smaller vocabularies and can thus be misdiagnosed with LI. The purpose of this study was to compare the fast-mapping (FM) skills of 3 groups of 4- to 9-year-olds: typically developing (TD) children with low socioeconomic status (SES) and mid SES, and mid-SES children with language impairment (LI), to ascertain whether FM is affected by SES. The FM items of the Diagnostic Evaluation of Language Variation were administered to 253 TD mid-SES children, 75 TD low-SES children, and 36 children with LI. On FM with novel verbs, the TD groups differed significantly (p = .001) as did the TD mid-SES and LI groups (p = .046), but not the TD low-SES and LI groups (p = 1.00). On a comparable task with real verbs, the TD mid-SES group also differed significantly from the TD low-SES (p < .001) and LI group (p = .018), with no significant difference between the latter two groups (p = 1.00). FM has been proposed as a non-SES-sensitive measure but, unlike previous studies, we found FM to be affected by SES, rendering it an insufficiently unbiased measure for our sample of children. Further thought should be given to measures that can successfully differentiate between children with LI, and children from low-SES backgrounds, possibly rendering scores adjusted for SES, so that targeted intervention can be offered.