Can infant vocabulary measures predict later reading skills?

The Oxford Communicative Development Inventory (OCDI) is a checklist of how many words infants can understand and say. Many parents have filled in these checklists when taking part in research at the Oxford University BabyLab.

In this study, the researchers followed up 300 babies to look at their reading and language skills once they were at primary school (between 4 and 9 years old).

They looked at whether infant vocabulary skills, as measured by the OCDI at age 1-2, can predict school-age language and literacy skills. If it did, this would support the idea that these vocabulary scores could be used to identify children who might be at risk for later language or literacy difficulties.

  • In general, those infants who had larger vocabularies in infancy went on to achieve higher levels of language and literacy in primary school.
  • However, the relationship between infant skills and school-age performance was not strong enough to support the recommendation that the OCDI be used to identify individual infants who might be at significant risk for later language and literacy difficulties.
  • Importantly, the study found that the prediction of which infants might go on to have reading difficulties was significantly improved by considering their family history. Infants with smaller vocabularies who came from a family where there was a history of reading or language difficulties were more likely to show reading difficulties themselves than children without family risk.
  • In collaboration with Professor Dorothy Bishop, the researchers took a closer look at those children identified in infancy as late talkers. In general, these children were at no greater risk than average talkers. However, those children who continued to show language difficulties at 4 years of age were at significant risk for reading and language impairments later on in primary school.