By Eliana Rosenzweig
Recent research suggests the notion that laughter made by babies is more similar to the laughter made by non-human primates, such as chimpanzees, than to that made by adults and even children. Disa Sauter, psychologist at the University of Amsterdam, and other researchers as well as phoneticians, conducted a study to examine the laughter differences in a population of 44 infants and children between the ages of 3 and 18 months of age. 102 listeners from a psychology student population analyzed the laughter of the babies presented on online videos. Specifically, they were focused on discerning the laughter as the production of an inhalation, an exhalation, or both. It was found that the youngest babies frequently laugh using both inhalation and exhalation, which is similar to the laugh of the non-primate population. In contrast, the rest of the infant population more frequently laughed only on the exhalation, which is also seen in children and adults. Although there is no definitive explanation for this distinct difference in laughter, Sauter suggests that the slow yet eventual shift in the laughter process is a direct result of the development of vocal control, which naturally occurs when babies learn to speak. Furthermore, the youngest babies will typically laugh as a result of physical play such as tickling, while older babies will begin to laugh as a result of emotional and social interactions with others.
The next steps for Sauter’s research team and this general area of research include confirming results with expert phoneticians and determining if there are further implications for this study associated with vocal-related developmental disorders in babies. Further research is also looking to establish if there are other differences in the vocalizations of newborn babies besides laughter.
Acoustical Society of America. (2018, November 7). How do babies laugh? Like chimps!. ScienceDaily. Retrieved November 18, 2018 from www.sciencedaily.com/releases/2018/11/181107130301.htm