Babbling is a key stage in language acquisition. We can see where it fits into the overall progression in the following “very rough” table taken from Jean Aitchison’s The Articulate Mammal: An Introduction to Psycholinguistics:
|Language stage||Beginning age|
|Intonation patterns||8 months|
|1-word utterances||1 year|
|2-word utterances||18 months|
|Word inflections||2 years|
|Questions, negatives||2¼ years|
|Rare or complex constructions||5 years|
|Mature speech||10 years|
After the cooing or gurgling phase from which it develops, babbling has a distinctly speech-like quality because it features “sounds that are chopped up rhythmically by oral articulations into syllable-like sequences”, as Mark Liberman describes it.
The sounds most associated with babbling are mama, papa, dada, nana and slight variations thereon — as for example in the well-known video of twin babies repeating dada (and dadadadada, etc.) to each other.
This is true of a great many languages from different language families and parts of the world. The remarkable correspondence can be seen in a list included in Larry Trask’s “Where do mama/papa words come from?”, about which more below: