Mothers are happier, more articulate with babies, puppies - study

If you’re a new mother and also have taken possession of a new puppy as a pet, you are certainly very busy. But another sure is that you speak to both newborns with the same type of articulation – using clear and distinct sounds and higher and more-variable pitch in shorter sentences.

Having babies and puppies promotes a positive emotional state in human mothers, according to an international team headed by Dr. Alejandrina Cristia, an Argentinian linguistic researcher at the French National Center for Scientific Research (CNRS). They studied the vocal behavior of 10 mothers to better understand why they seem to articulate more when speaking to infants. 

“Happy speech” is often perceived as more intelligible, in part because smiling during speaking often acts to shorten the vocal tract and widen the mouth, they wrote. 

Mothers hyperarticulate and express positive emotions 

Participants were asked to speak to a puppy, to their six-month-old baby and to an adult for about 10 minutes. They compared mothers’ speech to their six-month-old infants, to eight- to 12-week-old puppies and to adults. Researchers extracted every vowel from the recordings, studied their acoustic characteristics and measured the emotions expressed. Surprisingly, the team found that mothers articulated better and expressed more positive emotions when speaking to their babies or to puppies and their range of positive emotions correlated with changes in their vocalizations. 

They anticipated that if hyperarticulation is primarily driven by its didactic purpose, it would be present when talking to human infants, but not to puppies or adults. But they found to their surprise that puppies elicit as much positive emotion as human infants (which is greater than to adults), hyperarticulation would be equivalent in infant-directed speech to both human infants and puppies, but not to adults. 

Publishing their findings in the Journal of Child Language under the title “Positive Valence Contributes to Hyperarticulation in Maternal Speech to Infants and Puppies,” the team found that hyperarticulation leads to a clearer pronunciation of words and makes speech easier for infants to process. They suggested that future studies on maternal speech should consider their emotional state.