In linguistics, mama and papa are considered a special case of false cognates. In many languages of the world, sequences of sounds similar to /mama/ and /papa/ mean "mother" and "father", usually but not always in that order. This is thought to be a coincidence resulting from the process of early language acquisition.These terms use speech sounds that are among the easiest to produce: bilabials like /m/, /p/, and /b/, and the open vowel /a/. They are, therefore, often among the first word-like sounds made by babbling babies (babble words), and parents tend to associate the first sound babies make with themselves and to employ them subsequently as part of their baby-talk lexicon. Thus, there is no need to ascribe to common ancestry the similarities of !Kung ba, Aramaic abba, Mandarin Chinese bàba, and Persian baba (all "father"); or Navajo amá, Mandarin Chinese māma, Swahili mama, Quechua mama, and Polish mama (all "mother"). For the same reason, some scientists believe that 'mama' and 'papa' were among the first words that humans spoke.Variants using other sounds do occur: for example, in Fijian, the word for "mother" is nana, the Turkish word is ana, and in Old Japanese, the word for "mother" was papa. The modern Japanese word for "father," chichi, is from older titi. Very few languages lack labial consonants (this mostly being attested on a family basis, in the Iroquoian and some of the Athabaskan languages), and only Arapaho is known to lack an open vowel /a/. The Tagalog -na- / -ta- ("mom" / "dad" words) parallel the more common ma / pa in nasality / orality of the consonants and identity of place of articulation. The linguist Roman Jakobson hypothesized that the nasal sound in "mama" comes from the nasal murmur that babies produce when breastfeeding:
"Mama" is a universal word, describing the woman who gave us the most cherished love in our most vulnerable state. ... The definitive study on "mama and papa" as universal terms was conducted by Russian linguist Roman Jakobson. He explained that the easiest vocalizations for a human to make are open-mouth vowel sounds.