The latest research shows that moms and dads use baby talk in different ways, and that boys and girls respond to them differently. In a study published in the online edition of Pediatrics, researchers looked at the language interactions between 33 late preterm and term infants and their parents by capturing 3,000 hours of recordings. Taking advantage of a small recording device called LENA, which they attached to the babies on a vest for 16 hours, researchers analyzed all of the verbal interactions in a group of 33 babies. The recordings occurred just after they were born, while the infants were still in the hospital, and again at about one-month-old. The last two sessions were recorded on days when both parents were home.

From more than 3,000 hours of recordings, the scientists got a good snapshot of the babies’ verbal environments. The results were both expected and surprising. When babies made sounds, moms were more likely to respond to them verbally than fathers were — “Oooo, sweetie pie, you’re talking this morning.” Mothers responded 88% to 94% of the time to the babies’ vocalizations, while dads responded only 27% to 33% of the time.

“We wanted to look more at gender and factors that affect these essentially mini-conversations that parents have with infants,” says lead author and neonatologist Dr. Betty Vohr, director of the Neonatal Follow-Up Program at Women & Infants Hospital of Rhode Island and professor of pediatrics at Alpert Medical School at Brown University.

“Infants are primed to vocalize and have reciprocal interactions. It seems to me that adults talking to children is absolutely the most cost effective intervention a family could do to improve children’s language,” says researcher Vohr, Perhaps because of the increased responsiveness, both boys and girls were also more likely to respond to their mothers’ or female voices than they were to male voices.

Indeed, when infants do vocalize (think of that little coo or heart-ripping yell), moms are immediate responders, while “Dads are more relaxed,” says Vohr.

Vohr says it’s possible that mothers may use more motherese — the higher pitched, sing song-y conversational tone that women, more than men, tend to adopt with infants. Mothers may also pair their vocal interactions with more eye contact with the baby, encouraging them to respond more when they hear their mothers’ voices. There were other intriguing gender-based differences. When Vohr compared mothers of girls to mothers of boys, she found that mothers of girls responded more frequently to their babies’ sounds than mothers of boys did to theirs. The same trend occurred for dads; those who had boys tended to respond more frequently to their infants than those who had girls.

“We’re not certain why that is, but the important thing here is knowing that of critical importance in early language development is the need to encourage both parents,” says Vohr. “The more we learn about it, the more we can inform parents of the power they have in just talking and interacting with their infants to improve the long term outcomes for their child and their school readiness.”

Previous studies have documented that the amount of verbal interaction, or “conversations” babies are exposed to even before they can speak, can predict their later language skills and even academic performance in school. In a study published earlier this year in Pediatrics, Vohr and her colleagues found that premature babies, who often experience language delays, benefit from being exposed to adult “baby talk” as early as possible. The researchers found that infants from birth through age 7 months were exposed to significantly more speech from moms compared to dads, and that infants preferentially responded to mothers’ compared to fathers’ speech. They also found that infants hospitalized in the neonatal intensive care unit, or NICU, were exposed to less speech compared to infants who were able to stay in rooms with their moms.

Although the researchers aren’t sure why moms spoke slightly more to infant girls rather than boys, they think it may be due to the fact that girls do have earlier brain maturation, make more eye contact and are better at “joint attention,” a kind of shared focus of two individuals on an object. A significant gap in language input from dads could have longer-term implications for children as they mature. Indeed, studies have shown that dads’ language input, basically their involvement in speaking to infants and young children, may also be a predictor of a child’s language skills as they mature.

“This is an interesting study in terms of gender differences, but we do know that moms talk more to their kids than dads because moms spend more time with infants and children,” says Dr. Lynne Vernon-Feagans, the William C. Friday Distinguished Professor of Early Childhood, Intervention and Literacy and professor of psychology at the University of North Carolina. “But what I think is a real message here is that both parents play a role in language development.” Her research suggests that fathers — not moms — actually may have more influence on a child’s language development. In a study of 1,200 infants in two-parent households, she and colleague Nadya Pancsofar at the College of New Jersey found that a dad’s education and vocabulary usage when reading to kids at 6 months of age were directly related to how expressive a child was at 15 months. And dads wound up influencing how advanced a child’s language skills were at 3.

The bigger question is should we be worried about boys getting what seems to be the shorter end of the conversational stick in early infancy?

“My take is ‘no,’ there’s no reason to worry because it seems to even out as a child gets older,” says childhood development expert Dr. Julie Braungart-Rieker, University of Notre Dame professor of psychology and director of the William J. Shaw Center for Children & Families.

“If a child seems understimulated, engage with them more, and if a child is overstimulated back off a little bit,” she says. But it’s very important for both moms and dads to engage with their kids. “I would like to give these researchers credit for including dads in the research,” she says. “Too often fathers are forgotten.”

In fact, the researchers would eventually like to create an intervention program that would teach dads about their role in language development, Vohr says. “Dads often feel left out of the loop, and we need to bring dads into circle of care.”

We can tell parents about these studies in our infant massage classes. Sometimes parents are shy or embarrassed about their “parent-ese,” or feel they should speak to their infants like adults, when so much research tells us that “baby talk” is actually the best way babies learn and begin to speak their native language. Just as we encourage fathers to massage their babies, we can let parents know that dads talking to their babies proves to be just as important as moms.