Updated: Jun 3, 2021
Babies are constantly processing an incredible amount of information inside their adorable heads. In just a year, babies go from uttering cute coos to speaking their first intentional words. Are there things we can do to help our little one in their linguistic journey? Short answer: yes, parental interaction with baby is very important for language development!
The acquisition of language poses an interesting philosophical problem because unlike many other tasks which are learned through deduction, language is learned by induction. This means that instead of learning the rules of speech first before putting together specific sentences (deductive learning), babies have to infer language rules from the specific examples they hear. It's therefore unsurprising that the more words and sentences a baby is introduced to, the better. Research shows that when caregivers talk more to their babies, babies will know more words and recognize words faster when they get older (Hoff and Naigles, 2002; Hurtado et al., 2008, Newman et al., 2016). These studies show that maternal quantity of speech (how often mom talks to baby) and lexical diversity (mom's variability in words/phrases) at 7 or 18 months predict a child's lexical achievement (vocabulary and understanding) at 2 years. Word repetition has also been shown to aid vocabulary growth (Newman et al., 2016).
In addition to talking a lot, it's important to engage with your baby. "Infants learn more easily from interactions with human beings speaking than they do from audiovisual exposure [...], and their speech is strongly influenced by the response of others around them, such as their mother and father" (Kuhl, 2004). 8-12 month old babies increase the number and quality of their vocalizations when responding to parents' verbal feedback (Gros-Louis and Miller, 2018; Goldstein et al., 2003). Further, another study revealed that when mothers responded to their 9.5 month old baby's babbles, the baby "rapidly restructured their babbling, incorporating phonological patterns from caregivers' speech"(Goldstein and Schwade, 2008). Babies who didn't recieve feedback did not alter their babbling. These studies show that even before babies are capable of real speech, caregivers can provide crucial, real-time guidance to language development.
The manner in which you speak to baby is also important for language learning. Infant-directed speech (IDS; also called "motherese" or "baby talk"), is often used when mommas talk to their babies. IDS is characterized by exaggerated intonation, slower speech, shorter words and phrases, and grammatical simplification. Using IDS has been shown to help babies learn to talk. A study from Boston University assessed 7 and 8 month old infants' long-term memory for words when words were spoken in IDS and adult‐directed speech (ADS). They discovered that "word recognition over the long term was successful for words introduced in IDS, but not for those introduced in ADS" (Singh et al., 2009).
Babies learn language by experience, and mommas are in the position to provide their babies with a wealth of linguistic examples. Talk to baby often, use repetition and a diversity of words, respond to your baby's babbles/speech, and feel free to use that "motherese" voice that involuntarily bursts out of you whenever baby is near!
Hoff E, Naigles L. How children use input to acquire a lexicon. Child Dev. 2002 Mar-Apr;73(2):418-33.
Hurtado N, Marchman VA, Fernald A. Does input influence uptake? Links between maternal talk, processing speed and vocabulary size in Spanish-learning children. Dev Sci. 2008 Nov;11(6):F31-9.
Newman RS, Rowe ML, Bernstein Ratner N. Input and uptake at 7 months predicts toddler vocabulary: the role of child-directed speech and infant processing skills in language development. J Child Lang. 2016 Sep;43(5):1158-73.
Kuhl PK. Early language acquisition: cracking the speech code. Nat Rev Neurosci. 2004 Nov;5(11):831-43.
Gros-Louis J, Miller JL. From 'ah' to 'bah': social feedback loops for speech sounds at key points of developmental transition. J Child Lang. 2018 May;45(3):807-825.
Goldstein MH, King AP, West MJ. Social interaction shapes babbling: testing parallels between birdsong and speech. Proc Natl Acad Sci U S A. 2003 Jun 24;100(13):8030-5.
Goldstein MH, Schwade JA. Social feedback to infants' babbling facilitates rapid phonological learning. Psychol Sci. 2008 May;19(5):515-23.
Singh L, Nestor S, Parikh C, Yull A. Influences of Infant-Directed Speech on Early Word Recognition. Infancy. 2009 Nov 12;14(6):654-666.