Babies and puppies have at least two things in common: aside from being newborns, they promote a positive emotional state in human mothers, leading them to articulate better when they speak.

This finding is the result of research by an international team that included Alejandrina Cristia, a CNRS Researcher at the Laboratoire de sciences cognitives et psycholinguistique (LSCP) (CNRS/EHESS/ENS-PSL).

Scientists studied the vocal behavior of ten mothers to better understand why mothers articulate more when speaking to infants. Participants were asked to speak to a puppy, to their 6-month-old baby, and to an adult for about ten minutes.

Researchers extracted every vowel from the recordings, studied their acoustic characteristics, and measure the emotions expressed according to adults who were unaware of the context in which each vowel had been pronounced. Surprisingly, the team found that mothers articulated better and expressed more positive emotions when speaking to their babies or to puppies.

In both situations, mothers displayed a range of positive emotions, which correlated with changes in their vocalizations. Other research shows that hyperarticulation leads to a clearer pronunciation of words and makes speech easier for infants to process.

Published in the Journal of Child Language on 1 July, these findings demonstrate that future studies on maternal speech should consider the emotional state of individuals.