Effect of socio-economic status on cognitive control in non-literate bilingual speakers

Previous research has suggested that the advantages for cognitive control abilities in bilinguals are attenuated when socio-economic status (SES) is controlled (e.g., Morton & Harper, 2007). This study examined the effect of SES on cognitive control in illiterate monolingual and bilingual individuals who lived in adverse social conditions. We tested monolinguals and bilinguals using Simon and Attentional Network task while controlling for two potential confounding factors: SES and literacy. Bilinguals were faster for both trials with and without conflict demonstrating overall faster response times (global advantage) compared to monolinguals on both tasks. However, no bilingual advantage was found for conflict resolution on the Simon task and attentional networks on the Attentional Network task. The overall bilingual effects provide evidence for a bilingual advantage even among individuals without literacy skills and of very low SES. This indicates a strong link between bilingualism and cognitive control over and above effects of SES.