Researchers used highly faithful audio recorders — a system called Language Environment Analysis (known as LENA) — to capture every word spoken or heard by 36 4–6 year olds from various socioeconomic backgrounds over two full days. The recordings were analyzed to measure the number of words spoken by each child, the number of words spoken to each child, and the number of conversational turns — back-and-forth exchanges initiated by either adult or child.
Comparing those measurements with brain scans of the individual children, the analysis found that differences in the number of conversational turns accounted for differences in brain physiology, as well as for differences in language skills including vocabulary, grammar, and verbal reasoning.
Read the MIT News story for a fuller summary of the research. (Authors on the paper include Meredith Rowe of the Harvard Graduate School of Education, whose behavioral work has shown the importance of parent-child interplay; Martin West of HGSE, and senior author John Gabrieli of MIT.)
The “conversational turns” are key here, the researchers say. Conversational interplay — a verbal version of the serve-and-return caregiving that helps kids thrive — “involves not only a linguistic exchange, but also a social interaction that we know is crucial to cognitive development as well,” Romeo says.
This work suggests how important it is that caregivers “not just talk to your child, but talk with them,” says Romeo. “Even from infancy, we can consider children to be conversational partners. Obviously, a ‘conversation’ looks very different with much younger children: with infants, it might be taking turns exchanging giggles or coos; with toddlers, it might be repeating and expanding their sentences; and with older children, it might be asking ‘who, what, where, and how’ questions.
“Either way, it seems to be the interaction that best supports children's language skills and the underlying neural development.”