And lest any parent pull her infant out of day care in order to ensure he’s being responded to enough, Goldstein says, “The mix of responses a baby gets in a high-quality day care is probably ideal.”
Tamis-LeMonda also warns against overstimulation. Her moms weren’t responding at that high rate all day. “In my study, the mothers were told to sit down and play with their infant and these toys. But the same mom, when feeding the baby, might respond only thirty percent of the time. When the child is playing on the floor while the mom is cooking, it might be only ten percent. Reading books together, they’d have a very high response rate again.”
Goldstein has two other points of caution, for parents gung-ho on using his research to help their babies. His first concern is that a parent, keen to improve his response rate, might make the mistake of over-reinforcing less-resonant sounds when a baby is otherwise ready to progress, thereby slowing development. This would reward a baby for immature sounds, making it too easy for the baby to get attention. The extent to which parents, in a natural setting, should phase out responses to immature sounds, and become more selective in their response, is thus far unknown.
Goldstein’s second clarification comes from a study he co-authored with his partner at Cornell, Dr. Jennifer Schwade. As Goldstein’s expertise is a tot’s first year of life, Schwade’s expertise is the second year, when children learn their first 300 words. One of the ways parents help infants is by doing what’s called “object labeling”—telling them, “That’s your stroller,” “See the flower?,” and “Look at the moon.” Babies learn better from object-labeling when the parent waits for the baby’s eyes to naturally be gazing at the object. The technique is especially powerful when the infant both gazes and vocalizes, or gazes and points. Ideally, the parent isn’t intruding, or directing the child’s attention—instead he’s following the child’s lead. When the parent times the label correctly, the child’s brain associates the sound with the object.
Parents screw this up in two ways. First, they intrude rather than let the child show some curiosity and interest first. Second, they ignore what the child is looking at and instead take their cues from what they think the child was trying to say.
The baby, holding a spoon, might say “buh, buh,” and the zealous parent thinks, “He just said ‘bottle,’ he wants his bottle,” and echoes to the child, “Bottle? You want your bottle? I’ll get you your bottle.” Inadvertently, the parent just crisscrossed the baby, teaching him that a spoon is called “bottle.” Some parents, in Goldstein and Schwade’s research, make these mismatches of speech 30% of the time. “Beh” gets mistaken by parents as “bottle,” “blanket,” or “brother.” “Deh” is interpreted as “Daddy” or “dog,” “kih” as “kitty,” and “ebb” as “apple.” In fact, at nine months old, the baby may mean none of those—he’s just making a canonical syllable.
Pretending the infant is saying words, when he can’t yet, can really cause problems.
Proper object-labeling, when the infants were nine months, had an extremely strong positive correlation (81%) with the child’s vocabulary six months later. Crisscrossed labeling—such as saying “bottle” when the baby was holding a spoon—had an extremely negative correlation with resulting vocabulary (–68%). In real life terms, what did this mean? The mother in Schwade’s study who was best at object labeling had a fifteen-month-old daughter who understood 246 words and produced 64 words. By contrast, the mother who crisscrossed her infant the most had a fifteen-month-old daughter who understood only 61 words and produced only 5.
According to Schwade’s research, object labeling is just one of any number of ways that adults scaffold language for toddlers. Again, these are things parents tend to do naturally, but not equally well. In this section, we’ll cover five of those techniques.
For instance, when adults talk to young children about small objects, they frequently twist the object, or shake it, or move it around—usually synchronizing the movements to the singsong of parentese. This is called “motionese,” and it’s very helpful in teaching the name of the object. Moving the object helps attract the infant’s attention, turning the moment into a multisensory experience. But the window to use motionese closes at fifteen months—by that age, children no longer need the extra motion, or benefit from it.
Just as multisensory inputs help, so does hearing language from multiple speakers.
University of Iowa researchers recently discovered that fourteen-month-old children failed to learn a novel word if they heard it spoken by a single person, even if the word was repeated many times. The fact that there was a word they were supposed to be learning just didn’t seem to register. Then, instead of having the children listen to the same person speaking many times, they had kids listen to the word spoken by a variety of different people. The kids immediately learned the word. Hearing multiple speakers gave the children the opportunity to take in how the phonics were the same, even if the voices varied in pitch and speed. By hearing what was different, they learned what was the same.
A typical two-year-old child hears roughly 7,000 utterances a day. But those aren’t 7,000 unique sayings, each one a challenge to decode. A lot of that language is already familiar to a child. In fact, 45% of utterances from mothers begin with one of these 17 words:
what, that, it, you, are/aren’t, I, do/don’t, is, a, would, can/can’t, where, there, who, come, look, and let’s.
With a list of 156 two-and three-word combinations, scholars can account for the beginnings of two-thirds of the sentences mothers say to their children.