Experimenting with Babies

by Shaun Gallagher

  THE TAKEAWAY

  Your little ragamuffin is a mind reader, at least in a rudimentary way. He is able to separate the facts that he knows from the facts that he thinks you know, and he sets expectations based on that knowledge. Being able to keep track of what other people know is a terrific developmental skill, because it allows us to make sense of their behavior. For instance, we may know that a hungry wolf has disguised himself as Little Red Riding Hood’s grandmother, but if we also know that Little Red Riding Hood is unaware of this, then we can understand why she would enter the house and address the wolf as if it were her grandmother. There’s little you can do to speed up your baby’s acquisition of this skill, but through experiments such as the one described here, you can determine whether it has been acquired. Once he’s reached a point at which he seems to understand the extent of other people’s knowledge, you can continue to devise little experiments to test just how much he knows. You may be surprised to learn that he knows more than you think!

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  Using Your Head

  Age range: 13–15 months

  Experiment complexity: Moderate

  Research area: Motor skills

  THE EXPERIMENT

  For this experiment, you’ll need an object that you can activate by touching it with your forehead, such as a small dome-style light or a toy that makes noise or lights up when it’s touched. Sit at a table opposite your baby and place the object in front of you. Raise your hands in the air, then get your baby’s attention by saying his name. With arms still in the air, lower your forehead to touch the object and activate its light or sound. Repeat the procedure several times, then ask your baby if he wants to try. Place the object in front of him so that he can also activate it if he touches it with his forehead. Observe whether he attempts to imitate you.

  A few days later, repeat the experiment, but this time, don’t put your arms in the air. Instead, place your hands on the table, so that your baby can see that you could tap the object with your hands if you wanted to, but that you are purposely using your head instead.

  THE HYPOTHESIS

  The first time you conduct the experiment, your baby is unlikely to touch the object with his forehead. If he does make an attempt, he is unlikely to put his hands in the air as he does so. The second time you conduct the experiment, your baby will be more likely to imitate your action—that is, touching the object with his forehead, with his hands on the table.

  THE RESEARCH

  In a 2011 study, 14-month-old babies were split up into several groups. Each group was shown the forehead-touch action but with slight variations in the method demonstrated. For instance, in one group, the person who demonstrated the action had her hands free; in another, her hands were raised in the air; in another, her hands were not visible and presumably occupied; and in another, her hands were holding small balls but were otherwise able to tap the object. The researchers found that babies in the hands-free group were twice as likely to imitate the action as those in the hands-in-air group.

  The same results had been seen in a similar study nine years earlier. In that study, the researchers theorized that the babies in the hands-free condition assumed the person demonstrating the action had a good reason for touching the object with her head, even though her hands were free to touch it, and thus they were more willing to use the same head-touch method when imitating the action. In contrast, the babies in the hands-occupied condition assumed that because her hands were not free to touch the object, she had no choice but to use her head to touch it instead. The authors thus concluded that babies are able to take into account the rationale behind an action when imitating it.

  But the researchers in 2011 put forth an alternate explanation: It is the baby’s existing motor skills, rather than the rationale behind the action, that has the stronger effect on imitation. The results of their study support that explanation. In both the hands-free and hands-in-air conditions, the demonstrator’s hands were ostensibly available to touch the object. But in the hands-free condition, the action was closer to the babies’ existing repertoire of motor skills than in the hands-in-air condition. In fact, the researchers note, even among the babies in the hands-in-air group who did touch the object with their heads, not a single one did so with their hands in the air. Thus they concluded that a baby’s degree of familiarity with a particular motor skill—what the researchers call motor resonance—has a bigger effect on imitation than the rationality of the action.

  THE TAKEAWAY

  Here’s a case in which two very plausible reasons for a baby’s behavior have been put forth, but only one is the true explanation. You’ll likely find that in your daily interactions with your child, you’ll encounter many instances in which such dueling hypotheses occur. Perhaps one parent thinks baby’s not napping well because he’s uncomfortable, and the other parent thinks he’s not tired. Or maybe you’re not sure whether your baby’s eating lint off the floor because he’s hungry or just a clean freak. Sometimes, it’s simply impossible to know for sure, and other times it only takes a different perspective to see what is really going on. So if you’re stumped, don’t be afraid to ask around. Your pediatrician, your friends, and even your other children may be able to offer some compelling arguments.

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  A Questioning Look

  Age range: 13–18 months

  Experiment complexity: Moderate

  Research area: Cognitive development and social development

  THE EXPERIMENT

  Select three small objects that are safe for your baby to hold and manipulate. Try to choose objects whose names your baby would not recognize, such as a pedometer, a trivet, or a knickknack. Place your baby into a high chair or other seat. On a table or other flat surface in front of her, place one of the objects to her left and one to her right, both out of her reach. Now, have a friend sit in front of your baby, so that the objects are between your baby and your friend. The friend should stare at the center of the table, so that his eyes are not fixed toward either of the two objects, and say, “Look at the toma! There’s the toma. Do you see the toma?” Then, he should spend about 10 more seconds staring at the center of the table while you observe your baby. Be on the lookout for how many times your baby glances at the friend during that time, and for how long.

  Some time later, repeat the experiment, but this time use only the third object. Place it in either the left position or right position and leave the other position empty. Your friend should follow the same procedure, but this time, have him label the object a “modi.” Again, watch how many times your baby glances at the friend afterward.

  THE HYPOTHESIS

  Your baby will glance at the friend more often when there are two objects on the table than when there is only one.

  THE RESEARCH

  In a 2011 study of 13- and 18-month-old babies, half of the babies in each age group were assigned to the two-object condition, and the other half were assigned to the one-object condition. The researchers wanted to see how the babies in the two-object condition would attempt to resolve the ambiguity they were presented with: one word that could refer to either of the two objects. They found that the babies looked to the experimenter for clarification more frequently than did the babies in the one-object condition, who appeared to be able to connect the label with the single object and thus had less of a need for clarification. Presumably, the babies in the two-object condition were trying to figure out which of the objects the experimenter was looking at, which would help them determine which object the experimenter was referring to.

  What’s fascinating about the results of this experiment, the researchers point out, is that the babies in the two-objects condition were able to understand that an ambiguity existed and that they needed more information to resolve the ambiguity. In addition, they knew to look to the experimenter in an attempt to get more information. The findings have implications for researchers who study language ac
quisition. Specifically, they indicate that babies as young as 13 months old rely on social cues, such as the direction of a person’s gaze toward an object, to resolve ambiguities when learning new words.

  THE TAKEAWAY

  You are your baby’s Google. Now that you know your baby will actively look to you in situations in which she needs more information, you can be on the lookout for them and respond accordingly. For instance, if you tell her to “go get the ball” or “pick up the toy” and you get an uncertain glance in response, you might want to look at the object to which you are referring and point to it for reinforcement.

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  Power Napping

  Age range: 15 months

  Experiment complexity: Complex

  Research area: Language development

  THE EXPERIMENT

  Start the first part of this experiment before a scheduled nap. Your goal is to familiarize your baby with a language pattern in which words are bookended by the same set of nonsense syllables. The prefix for each word will be pel, and the suffix will be rud. So, for instance, you might recite the following words to your baby:

  Pel-ladder-rud. Pel-coffee-rud. Pel-giraffe-rud. Pel-soda-rud. Pel-armchair-rud.

  Continue with the recitation, using the same pattern, until you’ve rattled off about 30 words.

  Conduct the second stage of the experiment after your baby takes a nap. Capture your baby’s attention and start a timer. Begin reciting one of the following test sets of words and stop the timer when she looks away.

  Familiar Test Set

  In this test set, you’ll use the same two nonsense syllables you used in the first part of the experiment (pel as prefix and rud as suffix). Feel free to use the example words below, or make up your own.

  Pel-pickle-rud. Pel-truck-rud. Pel-Vermont-rud. Pel-joyful-rud. Pel-sleet-rud. Pel-after-rud.

  Unfamiliar Test Set

  In this test set, you’ll use a different pattern of nonsense syllables. For some words, use jic as a prefix and rud as a suffix, and for other words, use pel as a prefix and vot as a suffix. Feel free to use the example words below, or make up your own.

  Jic-random-rud. Pel-pucker-vot. Jic-candy-rud. Pel-woman-vot. Jic-lake-rud. Pel-into-vot.

  Repeat the process several times, alternating both test sets.

  THE HYPOTHESIS

  Examine your baby’s looking times—starting from when you capture her attention and begin reciting a test set and ending when she looks away. She is likely to show little difference in looking times between the two test sets. However, if she does show a preference, it will probably be for whichever test set came first.

  THE RESEARCH

  A 2006 study examined whether napping enhances a baby’s ability to figure out patterns that occur in language. During the study’s familiarization stage, babies were exposed to a set of nonsense words that shared a common construct: They began with one of two syllables (such as pel), and each of those beginning syllables had a corresponding ending syllable (such as rud).

  Four hours later, the test stage was conducted. The researchers conducted the study in such a way that for about half of the babies, that four-hour stretch would fall during their regular naptime, and for the other half, it would be during a period when the babies did not regularly nap.

  The babies who napped showed no looking-time preference between the familiar and unfamiliar test sets. The babies who did not nap, on the other hand, showed a significant preference for the familiar test set.

  The researchers theorize that the babies who napped had been able to generalize the rules that governed the construction of the nonsense words, and thus they showed little distinction in their responses to the familiar and unfamiliar test sets. To the nappers, each of the words in both test sets followed the same general rule: a root word with a prefix that was associated with a particular suffix. Thus, in a sense, even the unfamiliar words were familiar because they followed the same language rule.

  The non-nappers, on the other hand, were able to retain the specific test words in their memory over a four-hour period—no small task!—but apparently were not able to form a generalization about the structure of the nonsense words. Thus there was nothing familiar to them about the unfamiliar test set, and so they showed a preference for the words they recognized rather than words they had never heard before.

  THE TAKEAWAY

  It’s the goal of every hard-partying college student: to find a way to nap and study at the same time. Turns out, in babies, that’s exactly what’s happening. Though we don’t know exactly how napping causes the language generalization demonstrated in the study, it’s obvious that sleep is a key part of the process. Fortunately, at least in this case, everyone’s best interests are aligned: No parent in her right mind is going to object to her baby taking a good, long nap—and, it turns out, the nap not only will rejuvenate her baby and put her in better spirits but also will help her acquire language. A little snooze may also enhance postnap learning. A 2011 study found that, at least in adults, the ability to commit things to memory improves after a nap. If that holds true for babies as well, then the period directly after a nap is a great time to expose your baby to new words and content-rich activities, such as reading and singing.

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  Same or Similar?

  Age range: 14–20 months

  Experiment complexity: Moderate

  Research area: Language development

  THE EXPERIMENT

  Alternately show your baby two toys or other objects that are dissimilar in appearance. When you show the first toy, call it “bih,” using a slightly drawn-out, descending intonation for emphasis. Then show the second toy, and call it “dih.” Repeat the presentations somewhere between 10 and 20 times, until your baby starts to lose interest. Then, after a brief interlude, present the first toy again, but call it “dih.”

  THE HYPOTHESIS

  At 20 months, your baby will look longer at the toy the second time you showed it to him than he did the first time. But at 14 months, he is not likely to look longer.

  THE RESEARCH

  A 2002 study attempted to determine at what age babies are able to distinguish between similar-sounding words when they are used to label objects. They familiarized their 20-month-old test subjects with two nonsense words, “bih” and “dih,” that were used to label two toys. Then, for half of the babies, they presented one of the toys and used the familiar label. For the other half, they presented the toy but used the label that had been used with the other toy. They found that those who heard the unfamiliar label looked longer at the toy than those who heard the familiar label, which indicated that the former group had been able to distinguish between the two words and were surprised to hear the wrong label applied. The researchers then conducted the same experiment with 14- and 17-month-olds. The 14-month-olds did not appear to be able to distinguish between the two words, based on their looking times, but the 17-month-olds were able to make the distinction.

  Language-acquisition researchers have observed that at or around 18 months, babies become significantly better at learning new words and undergo a “naming explosion,” at which point they pick up words so quickly it becomes almost impossible for parents to make an accurate inventory of the words their baby can understand. Yet even though babies as young as 8 months old can distinguish between similar-sounding syllables, it takes much longer for them to distinguish between similar-sounding words when they are used to label objects. To determine at what point babies are able to make this distinction, this study examined babies who were several months away from the naming explosion, babies who were on the cusp of it, and babies who were a couple of months past the acceleration point. That the 14-month-olds did not distinguish between the nonsense words but the older babies did suggests that there is only a brief window of time when babies confuse similar-sounding words as they try to learn them.

  The researchers
also found that in all the age groups, babies with larger-than-average vocabulary sizes were best at distinguishing between the similar-sounding words. The researchers suggest two explanations for the correlation between vocabulary size and word-discrimination ability among the early word learners. One theory is that as vocabulary size increases, the likelihood of acquiring similar-sounding words increases, so the baby is forced to better distinguish between words. Another theory is that babies who are farther along in the word-acquisition process are able to devote more attention to subtle sound distinctions because picking up new words is not as taxing as it had been earlier in the process. This is the theory the researchers prefer, and they point out that it is consistent with earlier studies that suggest that when babies are faced with tasks that demand significant focus and brainpower, they are less able to pay attention to more subtle details.

  THE TAKEAWAY