Dinh, M., & Carr, L. (2018, September 09). Early language exposure is predictive of language skills and IQ in school-age children. Retrieved January 16, 2019

Researchers found that the frequency of children’s conversational turn-taking at ages 18 months to 24 months accounted for 14% of the variance in IQ scores and 27% of the variance in Verbal Comprehension Index scores at ages 9 to 13, after adjusting for socioeconomic status. The findings in Pediatrics also showed that adult word count was linked to IQ and language skills, but the association weakened after controlling for socioeconomic status.