Baby’s natural preference

     At birth, a baby already knows the difference between the sound of its mother’s voice and that of a woman other than the mother. The baby also knows the difference between the sound of the language the mother speaks i.e., “mother tongue”- and a foreign language. In fact, the baby doesn’t just know the difference, it prefers the mother’s voice and the mother tongue to any other. There’s good evidence that infants learn initially to sort mother tongue from foreign language by paying attention to prosody, well before they’ve learned to pay attention to specific words.

     The early preference for mother’s voice presumably exists because it aids in the process of bonding the infant to the mother. Mother-baby bonding has obvious survival value for the infant. But what about mother-tongue preference? After all, when it comes to many other things in the baby’s environment, it’s novelty the baby prefers over familiarity. So why should language be different?

      The newborn’s preference for the mother tongue is just the first step in a single-minded focus on the sounds it needs to pay attention to in the process of language acquisition. One of the most striking things about this step is how quickly infants learn to narrow their focus, and ignore data that aren’t relevant to the language –learning task.

Babies are self-taught linguists

     Babies come into the world primed to learn language. They’ll do it whether you want them to or not, without any instruction, in a sequence of stages that are the same for all children the world over, regardless of whether they’re learning Swahili, or English. All they need is a little data – data supplied automatically by their environment, as long as there are people around them who are speaking. Then they embark on a systematic analysis of their native language to be that is so skilled it would put a linguistics graduate student to shame. They are, in effect, like little natural-born linguistic anthropologists, eagerly and instinctively performing phonological, morphological, semantic, and syntactic analyses of the language of the natives in their newfound world so they can figure out the rules of that language and become expert speakers themselves.

     Standard psychology textbooks will tell you that the stages of language acquisition go something like this. From about four to six months of age, infants produce brief, isolated consonant and vowel sounds as well as clicks, coos, grunts, and sighs that bear little or no resemblance to speech sounds in any language. At about six months, they begin what’s called the babbling stage, mouthing repetitive consonant-vowel sequences. Around the turn of the first year, the infant moves beyond babbling and begins to produce recognizable words in the language spoken around it.

The eyes have it

     Humans are social animals. In our evolution, we’ve developed the ability to deduce what another person might be thinking, when they do or say something, and to predict their behavior based on that deduction. Communication that passes between two people goes beyond a simple understanding of the words that are exchanged. Infants begin to pick up non-verbal signals well before they have learned to speak.

     From the age of about four months, babies learn to look at other people’s eyes to figure out what their intentions might be. Even from the age of two months, infants look longer at the eyes than at any other part of a face. To most animals, direct eye contact is considered threatening; to humans, a look can also send a friendly, affectionate signal.

     From about the end of the first year of life, babies learn to infer from the direction of an adult’s gaze what the adult is looking at or thinking about. This is something other animals, with the possible exception of some primates, do not do. Babies also learn, by about the same age, to direct the attention of an adult to an object, by moving their eyes between the object and the adult’s eyes, as well as by pointing. 

Fetus learns in the womb

     Other studies have even gone inside the womb to explore the capacity of third-trimester fetuses to learn. How can such an experiment be done? If you make a noise by placing a “vibroacoustic stimulator” against a pregnant mother’s abdomen, the fetus will move. If this is done repeatedly the fetus will eventually stop moving in response to the noise. That shows that the fetus has habituated, it has learned to recognize the sound and tune it out. A fetus will show the effects of this simple kind of learning – responding less persistently to the same stimulus reapplied in the future not just after ten minutes, but even after 24 hours.

     Survival of a helpless newborn depends on bonding with the mother immediately after birth, presumably an infant’s brain must be sufficiently developed to recognize matters essential for its post-natal well-being. Therefore, the bonding process must begin prior to birth. As we’ve seen, to conserve energy the fetus is able to learn not to react when a new event has proven that it is not a danger. To identify its food-source later on, the fetus acquires the life-preserving ability to recognize and crave the sound of its mother’s voice.

Memories formed in the Womb

     It takes a newborn a little longer to recognize its mother by her face. Since there’s no way a baby can come into the world already armed with the knowledge of what its mother looks like, it has to learn this after birth by matching the mother’s voice to the face it’s coming from.  At one month, infants can match their mother’s voice to her face. They prove it by looking at the mother’s face, and ignoring the face of another woman sitting by her side, when a tape-recording of the mother’s voice is played. After about three months, an infant can pick out its mother by sight alone.

     One might think the newborn could have learned a preference for its mother’s voice while bonding with the mother just after birth. But it goes deeper than that. In an experiment in which pregnant mothers read a certain story out loud once a week for the last six weeks of pregnancy, their newborns turned out to prefer that story to others. Another study showed that when pregnant women sing a certain melody once a day during the last two weeks of pregnancy, the babies prefer that melody to an unfamiliar one after they’re born.

Learning begins in the Womb

     The powerful need that a baby has to learn is matched by an unusual ability which unfolds gradually in the infant brain. Its helplessness acts as a powerful motivator to figure out how to survive in its new environment when it can no longer depend on the peaceful, protected life in the womb where learning had already started. Investigators into the development of infant learning and memory have discovered the fetuses are not only listening to what’s going on outside the womb, but are already capable of some basic kinds of learning and remembering. In other words, even before we’re born, we’re forming memories.

     Any mother knows that her baby prefers her voice to that of any other person. That isn’t just motherly conceit. Even before three days of age, newborns are capable of telling their mother’s voice apart from other women’s voices. Not only that, they’re so fond of their own mother’s voice they’ll do whatever’s in their power to hear it. Psychologists know this because of experiments in which a newborn infant is permitted to “produce” a voice turn on a recording of a woman reading a story by sucking on a specially-rigged pacifier. If it’s their own mother’s voice they turn on by sucking, they’ll do so more vigorously and frequently than if it’s the voice of some other woman.

Human Brain Less Mature At Birth

     Human babies come helpless and dependent into the world, more so than the young of any other species. A baby elk can stand a few hours after birth, and run within a day. On the other hand, human babies, with their eager, adaptable brains, are able to learn far more in their first two years of life than an animal ever will. They can even master the basics of the miraculously complex, uniquely human skill language.

     A leading theory is based on the fact that humans walked upright while their ancestors used their arms as forelegs, walking on their knuckles as the apes do. Perhaps the first humans stood upright so they could see above the grasses in the savannas in order to spot predators and game. Upright posture may also have allowed their bodies to keep cool by venting heat through the head into the moving air above the grasses.

     In the course of evolution the upright position must have shifted weight to the pelvis, which thickened to bear it, closing down the birth opening. As the pelvis was thickening, the head of the fetus continued to grow larger to accommodate the constantly enlarging brain. Whatever the reasons, the human fetus had to be born well before the brain and head had reached maturity so it would still be small enough to pass through the birth canal.