Baby talk – the supposedly soothing but seemingly senseless babble we coo at little ones – appears to be almost universal around the world, according to a landmark new study. Next time you catch yourself chattering sing-songy nonsense to a bemused baby, know that you are not alone in your ridiculousness.
Published in the journal Nature Human Behaviour, the study analyzed over 1,600 recordings of over 400 people from 21 diverse societies worldwide, making it the most wide-ranging study of its kind. The research included 18 different languages, spanned six continents, and found that when interacting with babies, people change the way that they speak in a way that is nearly universal across cultures.
From vastly-populated urban cities such as Beijing to rural hunter-gatherer communities in Tanzania, “parentese” – as baby talk is more formally known – can be observed.
“Across all sites, people use a higher voice when speaking to infants than they do when speaking to adults,” Dr Samuel Mehr, senior author of the research, said in a statement.
“But the difference in pitch is much larger in some societies than others – some of the biggest differences were in New Zealand English, whereas other languages, like Hadza in Tanzania, had smaller effects.”
As well as using a higher and more variable pitch, global consistencies in parentese include using a musical voice, singing with a purer timbre, and changing tempo. In total, baby talk differed from adult talk in 11 ways, a machine-learning model found. There was variability across cultures, according to the findings, but this could still point to a possible function of baby talk and baby song in infant development and parent-child bonding.
“Our study provides the strongest test yet of whether there are acoustic regularities in infant-directed vocalizations across cultures,” Courtney Hilton,co-first author on the paper, told The Harvard Gazette.
“It is also really the first to convincingly address this question in both speech and song simultaneously. The consistencies in vocal features offer a really tantalizing clue for a link between infant-care practices and distinctive aspects of our human psychology relating to music and sociality.”
Previous research has suggested that babies may be soothed by the sounds of baby talk or lullabies, regardless of what language they are in.
In the new study, researchers recruited 51,065 people from 187 countries, who spoke 199 different languages. They aimed to determine whether differences between baby talk and adult talk were also obvious to members of the public.
When asked whether a piece of speech or song was directed at an adult or a baby, the participants guessed correctly in most cases, irrespective of their native language or culture.
“While there is variability and cultural influence in [baby talk], there does seem to be some common biases likely rooted in our biology,” Hilton said on Twitter, summing up the study’s main findings.
“We speculate this as something evolved out of vocal emotion-signalling systems shared with other animals, and tied in important ways to the uniquely protracted and social contexts of human child development," Hilton continued.
"The ways we use these vocalizations to socially and emotionally communicate with infants, and regulate their emotions, is then also a conspicuous contrast to core ways we, as adults, experience and use music: as an emotionally and socially potent signal that plays various functions in our lives.”