About 30% of adults with autism are minimally verbal. Past research suggested that after age five, few gain verbal fluency, but studies have rarely investigated whether family environmental factors contribute to the acquisition of verbal fluency. The present study utilized data from the Autism Diagnostic Interview-Revised to compare changes in verbal fluency for 404 individuals with autism from childhood to adolescence and adulthood. Socioeconomic factors were examined across fluency groups (i.e., those who did/did not achieve verbal fluency). Findings indicated that fully 60% of those who were minimally verbal in early childhood acquired verbal fluency in adolescence and adulthood. Parent socioeconomic status differed across fluency groups, suggesting the importance of environmental factors for individual development.
Keywords: ADI-R; ASD; Lifespan development; Minimally verbal; SES.