Speaking to your baby in ‘parentese’ can add 40 more words to their vocabulary by the time they are 18 months, new research has revealed.
Researchers at the University of Washington enlisted 48 families, of which half of parents were taught how to use parentese, and half remained as a control group.
What is parentese?
Unlike nonsense baby talk, ‘parentese’ is fully grammatical speech that involves real words, elongated vowels and exaggerated tones of voice.
Spoken directly to the child, it sounds happy and engaged, and helps infants tune in socially to their parents and respond, even if only through babbling.
The parents and children were monitored over four separate weekends when the babies were six,10 and 14 months old.
Between 14 and 18 months, coached families showed a drastic jump in conversational turn-taking and child vocalisations.
Children of coached parents produced real words, such as 'banana' or 'milk' - at almost twice the frequency of children whose parents were in the control group.
'A social hook for the baby brain'
"We've known for some time that the use of parentese is associated with improved language outcomes," said Patricia Kuhl, professor of speech and hearing sciences at the University of Washington.
"But we didn't know why. We believe parentese makes language learning easier because of its simpler linguistic structure and exaggerated sounds. But this new work suggests a more fundamental reason.”
"We now think parentese works because it's a social hook for the baby brain - its high pitch and slower tempo are socially engaging and invite the baby to respond."
The families involved in the coaching group learned more about the cognitive and social benefits of parentese, when and how to use it to promote interaction with their child, and the positive effects that parentese could have on their child's language development.
The study was published in the journal Proceedings of the National Academy of Sciences.