Ellen Phiddian
Cosmos science journalist
Babies! Are your parents not talking to you enough? Try talking to them first: a new study has found that parents chat more to infants who chat to them.
The researchers, who have published their findings in Child Development, initially set out to learn why girls generally have bigger vocabularies than boys early in life. They theorised that parents might talk more to girls.
But they found that this was not the case: there wasn’t a gender gap in the amount parents spoke to their babies. Instead, the thing that influenced parents’ speech, was baby speech.
“This study provides evidence that children actively influence their own language environments as they grow,” says lead author Dr Shannon Dailey, a postdoctoral scholar at Duke University, US.
The researchers recruited 44 babies – 21 girls and 23 boys – and their families for the study. Once a month for a year, the babies wore a vest fitted with an audio recorder so the researchers could analyse 16 hours of chatter.
On a separate day each month, the babies wore a cap with cameras that recorded video.
The researchers tracked this monthly audio from the kids at six months old, through to 18 months – the age range where most children start talking.
In total, they collected 8,976 hours of sound.
“If it’s fully transcribed by the time I retire, I’ll be happy,” says co-author Elika Bergelson, a professor of psychology and neuroscience at Duke University.
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With the level of detail required for analysis, it takes around eight hours to transcribe one hour of audio – and the amount of baby talk makes it necessary that a human, and not an AI, does it. The researchers simplified things by examining only a couple of hours per recording, when the most talking was happening.
While they did find that girls had bigger vocabularies than boys, and they grew their vocabularies slightly earlier, the researchers didn’t find that girls talked more than boys in total.
Nor did parents talk more to girls – regardless of gender, caretakers talked more to children once they’d started talking too.
“It turns out that girls have a larger vocabulary by 18 months,” says Bergelson.
“And so that could’ve meant caretakers talk to girls more, but really they just talk to talkers more.”