The origins of dialog: mothers in 11 countries respond contingently to their babies’ vocalizations

Mothers’ speech to babies is known to promote their language skills and stimulate brain development. Mother-baby speech has been studied a lot in the United States, but less is known about mother-baby speech in other countries. This study explored mother speech to baby and baby vocalizations like cooing and babbling in 11 countries across the globe. Countries included in the study were Argentina, Belgium, Brazil, Cameroon, France, Israel, Italy, Japan, Kenya, South Korea, and the United States. Mothers (N = 684) were all first-time parents and their babies were 5½ months-old on average. An hour of natural mother-baby interaction was recorded and coded. Mother speech to infants and infant vocalizations varied greatly across countries. For example, mothers in Cameroon spoke to their babies an average of 80 times in the hour, whereas mothers in France and South Korea spoke an average of over 300 times in the hour. Rates of baby vocalizations also varied across countries.

Fig. 1. Contingency of mother and infant vocalizations by country
M ±95% confidence interval. The reference line at 1.0149 indicates a significant level of contingency. If an error bar overlaps the reference line, the behaviors are not significantly contingent in that country. Error bars that do not overlap across countries indicate significant differences between countries.

However, mothers who were more talkative did not necessarily have babies who were more talkative. Despite the wide variation across countries in rates of speech, mothers spoke contingently (within 2 seconds after the baby stopped vocalizing) when all countries were combined and in 9 of the 11 countries individually. In the 2 countries where mothers did not speak contingently, the pattern was similar to other countries but the effect did not reach statistical significance (see Fig. 1). Mothers who spoke more contingently to their babies also had babies who babbled back to them contingently as well. These findings suggest that, regardless of their overall level of talkativeness, first-time mothers and their babies develop a “dialog” before their babies even speak their first words. These conversational skills seem to unfold early, automatically, regardless of context, and without formal instruction.



Mother-Infant Contingent Vocalizations in 11 Countries.
Bornstein MH, Putnick DL, Cote LR, Haynes OM, Suwalsky JT
Psychol Sci. 2015 Aug


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