This study explores the effectiveness of the Instrumental Enrichment Basic program (IE-B) in enhancing cognitive and affective functions of young children. The IE-B is a cognitive intervention program based on Feuerstein’s theories of structural cognitive modifiability (SCM) and mediated learning experience (MLE). Thirty 3- to 4-year-old children were assigned to experimental and control groups. The experimental
group received the IE-B program for seven months (for a total of 48 hours) and was compared to the control group before and after intervention on tests of knowledge acquisition and vocabulary. Cognitive change was evaluated using a Chilean assessment battery that measured children’s language, cognition, and knowledge. The fi ndings indicate that children in the experimental group improved their performance more than children in the control group. Results indicate that IE-B can be used with socially disadvantaged children as young as 3–4 and that it leads to improvement in their performance.