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Infant-directed speech (IDS) – or commonly referred to as ‘baby talk’, ‘motherese’, ‘fatherese’, ‘parentese’ – reflect a caregiver’s instinctively singy-songy way of talking to infants. More specifically, this kind of speech is usually higher in pitch, slower in pace, more exaggerated in pronunciation and more enthusiastic-sounding. The speech is intentionally embellished and enunciations are overstressed to highlight the difference between the syllables and words that most adults would easily be able to distinguish in normal, ‘un-babified’ speech (adult-directed speech; ADS). 

In a way, adult speakers of a language can, without much thought, break down continuous speech into meaningful phrases and words. Babies, however, don’t have this automatic capacity to distinguish these boundaries yet. Imagine going to a foreign country not knowing what language they speak. If you try to eavesdrop in a conversation, it may prove difficult to make sense of where one word ends and another starts. 

Whatyouhearmaysoundsomethinglikeasinglewordgoingonandonwithoutaforeseeableend. This is what babies hear, or at least we have pretty good reason to believe this is what they hear. Despite also being continuous speech, baby talk differs in that the boundaries between words are often more highlighted so WWordsMmmaaayySsSsounddDddLllliiikkeeeEeThiiIisssSsss making it easier for babies to learn language as they develop. It’s not a wonder why babies would show a preference for baby talk.

Infant-directed speech (IDS) can help infants learn language because they receive speech sounds at a slower rate and more varied patterns of pronunciations, which allows infants to more easily identify cues of boundaries between words. In fact, past research has shown that the more IDS a child is exposed to, the better they remember words from before and more easily learn new ones.

Nonetheless, much of the knowledge regarding the benefits of baby talk were from research with monolingual babies, most of which were of English speakers. Until recently, we understood very little how these findings may apply to bilingual (and multilingual) communities. We have yet to confirm whether these benefits are the same across babies of monolingual and bilingual communities. We can start by asking if the preference shows similar patterns between these two groups. One may ask the following questions:

1. Does the preference for baby talk develop in similar ways between monolingual and bilingual babies?
2. What, if any, is the influence of the infant’s language background on their preference for baby talk? Does it differ for baby talk in their native vs non-native language?
3. And finally, how do we know if the preference for baby talk is unique to specific languages, but not others?

The final point is most relevant to Singapore given its diverse linguistic environment. The vast majority of infants in Singapore will grow up bilingual, with English and at least one of the many mothertongues spoken by caregivers and others living in this Little Red Dot. If a child grows up being exposed to English and Malay, would their preference for baby talk differ with a child exposed to English and Mandarin, or English and Tamil? What about a child who grows up in a predominantly non-English household (e.g. immigrant families, interracial couples)?

To address these three questions, Krista Byers-Henlein of Concordia University enlisted international researchers from 17 labs to conduct a large-scale examination of IDS preference among bilingual and monolingual infants. They wanted to find out if bilingual infants show a preference of IDS over ADS the same way monolingual infants do.

Now, you may be wondering, how do researchers determine an infant’s preference for IDS or ADS? They can’t speak that well yet to be able to tell you. Researchers who study infant populations leverage on an interesting observation about babies: they stare at things they find interesting. With that in mind, Krista Byers-Henlein and colleagues measured in their respective labs how long their baby participants looked when presented with IDS or ADS on an eye-tracking device. To do so, infants were exposed to English in IDS and ADS simultaneously, and were observed to see which one they prefer. The longer they looked at videos of one kind of speech indicated a stronger preference. Across four continents and seven countries, the research study collated results from a total of 333 bilingual and 384 monolingual infants to put this question to the test. That’s a lot of babies!

The multilab study revealed intriguing results. First, the findings indicate both monolingual and bilingual infants showed similar patterns of strong preference for IDS over ADS. Second, their preference for English IDS was influenced by their prior exposure to English. This suggests that an infant’s stronger preference for IDS may have something to do with what language they are often exposed to, which commonly coincides with their native language. Finally, and most interestingly, the relationship between an infant’s degree of bilingualism (i.e. relative exposure to each language during early development, e.g. 50% English and 50% Mandarin/Malay/Tamil) and IDS preference was complex. Though their exposure to English speech influenced their preference for English IDS, the degree of bilingualism itself did not influence IDS preference. This again emphasises the specific role of the language environment. With greater exposure to, say, English, the greater the sensitivity an infant will show towards English IDS.

Taken together, bilingual infants, as with monolingual infants, do prefer baby talk over non-baby talk. That being said, the language context the infant is exposed to, including the kinds of languages and the relative amount of exposure to each language, plays an important role. This may be more important for bilingual infants exposed to multiple languages, often at the same time.

Fun Fact: one of the labs that was involved in this study is a lab in the National University of Singapore, so you can be confident that these results can be applied to our local linguistic environment!

This editorial was adapted from ‘A Multilab Study of Bilingual Infants: Exploring the Preference for Infant-Directed Speech’ by our intern Jan Paolo and edited by our lab manager Fei Ting.

Original article:

Byers-Heinlein, K., Tsui, A. S. M., Bergmann, C., Black, A. K., Brown, A., Carbajal, M. J., … & Wermelinger, S. (2021). A Multilab Study of Bilingual Infants: Exploring the Preference for Infant-Directed Speech. Advances in Methods and Practices in Psychological Science, 4(1), 2515245920974622. https://doi.org/10.1177%2F2515245920974622

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