New research says how much you talk with babies is linked to their IQ in adolescence


Photo illustration showing child as a baby with his mom and then as an older child in early adolescence doing well in school

A 10-year study by LENA researchers confirms that the amount of talk with adults that babies experience in the first three years of life is related to their verbal abilities and IQ in adolescence. Two-way conversations in the 18- to 24-month age range may be particularly important. The paper, “Language Experience in the Second Year of Life and Language Outcomes in Late Childhood,” was released for the first time today through advanced online publication in Pediatrics.

The publication marks the longest-term longitudinal study on the relationship between interactive talk in early childhood and later life outcomes. To collect data for the analyses, researchers enlisted 146 families who had participated in the first phase of the study in 2006. That original study enabled LENA to develop its wearable “talk pedometer” technology, which automatically and accurately measures adult words, back and forth conversations, and other language data. In 2016, the children, who were then 9 to 14 years old, participated in language and cognitive tests.

“This research confirms a growing body of science that says adult-child interactive talk is essential to early development and success in school."

-Dr. Steve Hannon

The results: the adult words and especially the conversations the children experienced between 18 and 24 months correlated 10 years later with their IQ, verbal comprehension, vocabulary, and other language skills. The amount their parents talked to them was important, but the amount they talked with them (“conversational turns”) was even more important.

“It’s incredible that we are able to measure the relationship between the experiences of babies and their cognitive skills 10 years later,” said Dr. Jill Gilkerson, Chief Research and Evaluation Officer at LENA, and lead author on the paper. “It strongly supports what other research has shown: talk with babies may make a huge difference in their futures and there is a need to begin early, since parents’ talk habits in the 18-24-month window start forming from the moment the baby is born.”

Learn more about the conversational turns research in this webinar discussion featuring lead author Dr. Jill Gilkerson.

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This is the third study published in 2018 concluding the predictive nature of conversational turns over adult words alone, even after controlling for socioeconomic status. The previous two studies were conducted by researchers at MIT and Harvard who used LENA technology and brain scans to show a relationship between conversational turns and brain activity and structure in four- to six-year-olds. These newly published longitudinal results build on those findings by looking at children at an even younger age range and showing that the relationship between conversational turns and cognitive skills bears up over time.

“We know all of the child’s conversational partners matter, from their parents and primary caregivers to their child care teachers,” said Dr. Stephen Hannon, president and chief operating officer of LENA. “This research confirms a growing body of science that says adult-child interactive talk is essential to early development and success in school. For years, we’ve emphasized conversational turns as LENA’s most important measure, and it’s gratifying to have this added and powerful support for that prioritization.”

Read media coverage of the story on U.S. News & World Report, ABC News, CBC News, and Romper.

The paper has already received high praise. “By showing that parent-child verbal interactions in early childhood predict critically important outcomes through age 14 years (∼10 years later), the authors of this study have made a major contribution to this topic, with strong implications for American Academy of Pediatrics policy and clinical practice recommendations,” Drs. Alan L. Mendelsohn and Perri Klass write in Pediatrics.


The LENA Team is a dedicated group of professionals who are passionate about increasing awareness of the importance of early interactive talk. We are statisticians, speech-language pathologists, curriculum specialists, engineers, and linguists.

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7 Comments on “New research says how much you talk with babies is linked to their IQ in adolescence”

  1. I imagine you are all expressing a collective “Whew,” after this amazing study has been published. Thank you for giving us valid and current research to back up this important concept.

  2. And to think, it is so simple. Just having a conversation, just with yourself, describing what we are doing when they are infants grows into a back-and-forth exchange as they grow. Amazing findings! This will offer our babies the best possible chance of making it in this challenging world. Never mind all of the billions spent on the latest educational toys, just have a conversation! Thank you!

  3. The cost for this amazing brain development in our next generation is coming at the cost of parents’ reprioritized time (due a number of pressures). Interaction ” TIME ” technically is free but sad to say society fills it with other business now.

  4. I am an Education Coach in my program. We use LENA Grow here in our center(s). During my coaching sessions, teachers are able to see the beautiful, colorful, graphed report that shows overall and individual data. It gives teachers a picture of what the interaction equity in their classrooms look like; sometimes, they are spot on with knowing the capabilities of their students and teachers feel very proud at how the LENA Grow program has helped them to increase teacher-child interactions and adult word usage. The data from each recording strengthens teachers’ confidence and helps them set goals in between each LENA Day for themselves and their students. Teachers are pleased to see how much growth has taken place with their child(ren) since the first LENA Day to the last LENA Day. And…….TEACHERS LOVE THE STARS!!!

  5. My 19 months grandchild has a high verbal ability and I read with much interest your study.
    I speak Italian to him, and his mother both Italian and english and a nanny speaks polish and another nanny english.
    He understands us . He is able to recall words together like ‘this is not good’ ‘ lots of money’ and say with cmpetence in the right situation. In Italian he often puts three words together. I have been looking after him some days every week since he was 16 months. His dob is 29-09-2021.His name is Alfred, he lives in London and Cambridge.
    When he is with me we speak non stop all the time so much that in the evening I tun out of voice. He is curious about anythig happening, and we are discovering together the world around us. It’s never dull being in his company! I am 69 and I hope to live for the next 10 years to see Alfred’s development at school.

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