Skip to main content
November 18, 2018

Baby Talk Linked to Later Adolescent IQ

Talk isn’t cheap. It’s priceless.

Infants are seldom lauded as conversationalists, but the latest research says answering the coos and babbling pays off for them later in life.

The findings of a recent long-term study, “Language Experience in the Second Year of Life and Language Outcomes in Late Childhood,” by LENA researchers confirms the two-way interaction between adults and infants correlates with increased IQ, verbal comprehension, vocabulary, and other language skills ten years later.

The report, published in Pediatrics last month, marks the longest-term longitudinal study on the relationship between early childhood talk and later outcomes.

Lead author and LENA Senior Director of Research Dr. Jill Gilkerson wasn’t surprised by the findings. They added to those of recent studies from researchers at MIT and Harvard revealing an increase in brain activity and development linked to conversation early in life in children ages 4-6.

In this case, Gilkerson found it particularly compelling that conversational turns — back-and-forth interaction — benefited infants in the 18- to 24-month age group in particular.

“When you can take a child of 18 months and predict effects on IQ ten years later, it’s exciting,” she said.

Researchers enlisted 146 families who participated in the first phase of the study in 2006. In it, infants wore a digital recorder about “the size of a credit card and the depth of an Altoids box,” she said, from when they woke until bedtime, once a month for six months.

Ten years later, the children, then 9 to 14 years old, participated in language and cognitive tests that revealed increased lexicon and comprehension skills, “versus rote-learned knowledge,” Gilkerson said.

Although the same study was roughly done in the 1980s, inaugurating the concept of linking early word-rich environments to language development, today’s technology is a welcome update.

In the oft-cited study by Hart and Risley, The Thirty Million Word Gap, researchers took four years to transcribe and make sense of data collected for one hour every month from just 42 families.

Today, “there’s no way you can transcribe the amount of data we collected,” she said.

Outside of updated technology allowing for deeper and more timely insights into the developing brain, perhaps the best part is knowing talk is free.

In many instances, income is the most common predictor for decreased kindergarten readiness, reading skills, and academic outcomes. But these findings point to action accessible to all.

“With research like this, we see it’s conversational turns that predict outcomes more than socioeconomic status, and it’s easier to change talking habits than it is to change income status,” she said.

While parents come to mind first, she hopes to share the findings with early child care professionals in particular.

“Many babies will spend more than half of their waking hours with caretakers other than parents. They have a lot of power to impact babies, and we want to incorporate ‘turn taking’ in their day so they can influence trajectories long term,” she said.

This story comes from a partnership between the Suncoast Campaign for Grade-Level Reading and the Herald-Tribune, funded by The Patterson Foundation, to cover school readiness, attendance, summer learning, healthy readers and parent engagement. Read more stories at

Share this post