Alison Gopnik’s “The Philsophical Baby” is a great book. It’s full of fascinating experiments and it’s beautifully-written.
Developmental psychology has made great progress in the last 40 years. There are a lot of intriguing experiments designed to understand what is going on inside the minds of young children.
Often the symptom they are looking for is a stimulus capturing a baby’s attention. That piece of behavior is used to draw conclusions about what is going on in the mind of the baby.
Here are some of my favorite experiments from the book.
Tool creation - the rake task
"In another experiment we saw whether babies could discover a new use for an object - if they could, in a simple way, invent a new tool. I put a desirable toy out of the babies’ reach and placed a toy rake beside it. As with the ring, fifteen-month-olds sometimes did pick up the rake, but they couldn’t figure out how to use it as a tool. They pushed the toy from side to side or even, frustratingly, farther away from them, till they either accidentally got it or gave up. But older babies looked at the rake and paused thoughtfully. You could almost see the wheels spinning. Then they produced a triumphant smile and often a certain look of smugness. You could almost see the lightbulb switching on. Then they put the rake in just the right position over the toy and triumphantly used it to bring the toy to toward them."
Deferring pleasure - the cookie test
"Back in the sixties Walter Mischel would sit a pre-schooler in front of two big chocolate-chip cookies (or marshmallows or toys). He explained that the child could choose: she could eat just one of the cookies now, or she could get both of the cookies if she waited until the experimenter returned in a few minutes. The few minutes seemed like an eternity to the children. The videotapes of them squirming in their seats, closing their eyes, and literally sitting on their hands are both comic and pathetic. Most of the younger ones just couldn’t hack it - they gave in and took the single cookie. But children got much better at this kind of self-control between three and five."
"One of the most striking things about these studies was not just that the children got better but how they got better. You might think that children just developed more willpower, and there is some truth to that. But children also got better and better at doing things to their own minds to make them behave differently. The successful children put their hands over their eyes, or hummed, or sang. They did much better when they tried imagining that the marshmallows were merely big puffy clouds and not tempting treats. As adults we use similar strategies all the time to regulate our own actions. I put the chocolate on a high shelf out of reach or promise myself that I’ll get to go for a walk and buy flowers after the chapter is done, but not before.
”…These children learned some important things about how our minds work. For example, they learned that focusing on what you want make your desires more irresistible, while thinking about something else makes your desires less intense.”
Understanding that other people’s desires can differ from one’s own
"We showed fourteen-month-olds and eighteen-month-olds two bowls of food - broccoli and Goldfish crackers. All the babies, as you’d expect, loved the crackers and couldn’t stand the broccoli. Then the experimenter tasted a bit of food from each bowl. She acted as if she were disgusted by the crackers and happy about the broccoli. She said, "Ew, yuck - crackers" and "Mmm, yum, - broccoli," revealing that her tastes were the opposite of theirs. Then she put out her hand and said "Can you give me some?"
"The babies were a bit startled by the experimenter’s perverse tastes - they waited awhile before they did anything. Nevertheless the fourteen-month-olds gave the experimenters the crackers. But although the eighteen-month-olds had never seen anyone crazy enough to reject Goldfish crackers, they made the right prediction. They sweetly did what they thought would make the experimenter happy, however weird it might seem to them."
9 month olds understanding probabilities
"In a particularly dramatic recent study, Fei Xu at the University of British Columbia showed that even nine-month-olds understand some important statistical ideas. She showed babies a transparent box full of mixed-up red and white Ping-Pong balls. Sometimes the balls were mostly white with a few red ones mixed in, sometimes they were mostly red with a few white ones. Then she covered the sides of the box to hide the balls. The experimenter took five balls out of the now opaque box in succession, either four red and one white or vice versa. If you think about it, it should be surprising, though of course possible, that you just happen to pull mostly red balls out of a mostly white box. It could happen but it’s not very likely, and certainly much less likely than pulling out mostly white balls.
"Very young babies seemed to reason about probabilities in the same way. They looked longer at the experimenter when she pulled out mostly red balls from a mostly white box than she when pulled out mostly white balls from a mostly white box."
Baby brains have more neural pathways than adult brains
"Babies’ brains seem to have special qualities that make them especially well suited for imagination and learning. Babies’ brains are actually more highly connected than adult brains; more neural pathways are available to babies than adults. As we grow older and experience more, our brains "prune out" the weaker, less-used pathways and strengthen ones that are used more often. If you looked at a map of the baby’s brain it would look like old Paris, with lots of winding, interconnected little streets. In the adult brain those little streets have been replaced by fewer but more efficient neural boulevards, capable of much more traffic. Young brains are also much more plastic and flexible - they change much more easily. But they are also much less efficient; they don’t work as quickly or effectively."
Babies imitating adults
"Back in the seventies Andy Meltzoff showed that literally from the time they are born babies imitate the gestures and imitations and actions of other people. Nine-month-old babies can use this kind of imitation to learn about causes. These babies don’t just imitate actions, they recognize and reproduce the results of those actions. For example, a one-year-old walks into the lab and sees the experimenter tap his head on a box, which makes it light up. A week later she returns to the lab and sees the box on the table. She’ll immediately use her own head to get the box to light up.
"By the time they are eighteen months old babies can imitate in an even more sophisticated way. Gyorgy Gergeley showed babies an experimenter touching her head to the box, but now she had a blanket wrapped around her so that her hands weren’t available. If the other person’s hands are free the babies will tap their own heads on the machine. But if she’s wrapped up in the blanket and she taps the machine with her head, the babies will instead use their own hands. They seem to have figured out that you would use your hands if you could, but since you can’t you’re using your head instead."
Another imitation experiment
"Ed Tronick got nine-month-olds to watch their mothers suddenly adopt a perfectly still pose - a kind of impassive, iron face. As you might expect, the babies were perturbed by this, and often even started crying. But they would also produce a large number of unusual and expressive gestures, as if they were trying somehow to test what was wrong. In another study, instead of have a baby imitate an adult, the adult imitated the baby, mimicking everything that the baby did. Faced with this extremely peculiar behavior, one-year-olds performed a different kind of experiment. They produced odd exaggerated gestures as if they were testing whether the experimenter really would imitate these actions too. They would wiggle a hand in some particularly strange way to see if the adult would do the same. The babies were as intrigued by the mimicry as rue were by the stone face and, in each case, they tried to get a reaction from the adult that would help them figure out what was going on."
Babies have unfocused awareness of surroundings
"Babies and young children are not as good as older kids and adults at concentrating on just one thing. But they may be better at picking up incidental information. Suppose, for example, I give children a memory task. They look through a pack of cards, two at a time. They are told that they will have to remember what’s on the left-hand card but not the other card, so they should just pay attention to that card. Then at the end you test children on their memory for both cards. Older children are much better at remembering about the left-hand card than the other one - like adults they inhibit the unattended information, and they are also better at remembering the attended card than the younger children. But for younger children the two types of learning are much more similar. In fact, the younger children actually do better at remembering the unattended card than the older children do."
Guessing at what it is like to be a baby
"Rafael Malach and his colleagues put people in a Functional Magnetic Resonance Imaging (fMRI) machine. These machines track how much blood goes to different parts of your brain as you solve some problem or do some task, and that in turn tracks how that task activates different parts of your brain. You can use it to make all those pictures of brains "lighting up" that you see all the time in Scientific American. Most of the time the poor guinea pigs in these machines either get some tedious task to do, like clicking a button when a red "x" appears l, or else they just lie there. In both of these cases frontal areas of the brain are active - more active when the subjects perform an intentional planned action, but still buzzing along even when they just lie in the machine daydreaming.
"But Malach’s lucky subjects got to watch an absorbing movie instead, "The Good, the Bad and the Ugly" with Clint Eastwood. Rather amazingly, the brain patterns of nearly everyone tracked the events in the movie in the same way - Sergio Leone really knew how to get into your head. Even more striking, the frontal parts of the brain, the parts that plan and think and keep track of the self, were actually inhibited as people watched the movie. The back parts of the brain, the parts that are active in young babies, lit up instead. The subjects were plainly conscious but they weren’t self-conscious. They weren’t making plans or considering or weighing the movie, they were just totally into it. For a baby, watching a Mickey Mouse mobile may be like being utterly, blissfully, selflessly captivated by a good movie."
"Preschoolers have very different ideas about attention than adults do. They don’t seem to understand about attentional focus. For instance, we can show them Ellie, a developmental psychologist, staring at an interesting photograph of the kids in the preschool in a very plain frame. Ellie points to various kids in the picture, describing what they were like. Then we ask the children if Ellie was thinking about the kids in the picture and they all say yes. But we can also ask if she was thinking about the frame of the picture and they say yes, she was thinking about that, too. They don’t think she was thinking about everything - they say she wasn’t thinking about the chair in the next room. But they do believe she will be thinking about everything she sees - they don’t understand about inattentional blindness…. It could be that they experience consciousness in a less-focused way."
Creating false memories
"Elizabeth Loftus and her colleagues have done startling experiments about creating false memories in perfectly ordinary people. They began by suggesting that some event, like getting lost in the mall, had actually happened ("Your mom says you once got lost in the mall"). Then they asked people to try hard to bring the memory to mind, and suggested some of the details ("Remember, you hid by the fountain?"). By the end of the process, the people they tested were absolutely positive that they could remember that they had gotten lost in the mall. They had vivid episodic memories of the event, even though it had never actually happened."
Cued memory is easier than free recall
"For all of us, cued memory is easier than free recall, but the difference is much greater for preschoolers. They have terrific specific memories when they are cued but have a very hard time with free recall.
”You can see this in everyday life. You go through the preschool pick-up ritual and ask, inevitably, “What did you do today, honey?” The equally inevitable reply is “Nothing” or “I played.” This is in spite of the fact that the child went on an exciting trip and rode the rocket in the science museum, or fell dramatically off the jungle gym, or played snakes and ladders for the first time. Good preschools often include a little list of what has happened during the day for parents to consult. When you ask about each event, the same child who stubbornly said “Nothing” will be full of exciting details. It isn’t that the child is being balky, it’s just that she can’t seem to access her memories freely in the way an adult or even a six-year old would.”
Knowing the source of a belief
"Very young children also have special difficulty remembering where their beliefs come from [how they came to have the belief in the first place, who or what gave them the information etc]. For instance, in my lab we showed children a little cabinet with nine different objects inside different drawers: an egg, a pencil, and so on. Sometimes we actually pulled out the drawer and showed children the object. Sometimes we simply said, "There’s a pencil in this drawer," without opening it, and sometimes we said, "Let’s see if you can figure out what’s in this drawer - look, here’s a clue, it goes in the egg carton." Then we closed all the drawers, pointed to each one, and immediately asked two questions: "What’s in here?" and "How do you know? Did you see it or did I tell you about it, or did you figure it out from a clue?"
"All the children could remember what was in each drawer, but the three-year-olds had a great deal of difficulty remembering how they knew - they often said they had seen the egg in the drawer when they had been told about it or vice versa. The five year olds, on the other hand, could tell you about what they knew and about the particular experiences that led to that knowledge."
Sources and suggestibility
"One of my undergraduate students at Berkeley, Jessica Giles, had been very involved in the children’s legal system. We did an experiment to see whether children’s suggestibility was linked to their understanding of sources. We showed children a movie and asked them questions about it. Some of them were source questions "How do you know that the boy had yellow boots? Did you see them on the screen or did the boy tell you about them?" Some were the sort of leading questions that measure suggestibility. We might say "The boy had red boots, didn’t he?" even though the boots were yellow. We discovered that the children who could remember how they knew something were much more likely to resist the leading questions. And if we asked the children about sources first, and then asked the leading questions, they were much less suggestible. Making the source of the information vivid allowed even four year olds to resist the leading questions."
Baby-sitting amongst lemurs
"In allomothering female members of the group who are not actually direct genetic parents of the young play a major role in childrearing. Lemurs and langurs have teenage babysitters. Mother lemurs leave their babies with other young lemurs while they go looking for food."
"I can’t determine what will happen to my son when he grows up. I can’t tell whether he will get to go to Berkeley, or whether he will have a good life. But I can determine what will happen to him when he is a child. I can determine that he will get to go to a leafy playground and a preschool full of sandboxes and pet fish and toys. I can determine that he will have a picnic by the beach and hot chocolate on front of the fire. And, and least to some extent, I can determine that he will have a good mother (though this is tougher than the picnics and hot chocolate).
"We can control one very important aspect of our children’s adult lives. We can determine whether they grow up to be adults who remember leafy playgrounds and picnics and affectionate parents. We can’t ensure that our children will have a happy future - there, all we can do is move the odds around. But we can at least try to ensure that they will have a happy past."
Two ideas about where moral beliefs come from
"Just making an emotional facial expression can itself lead you to feel the accompanying emotion. Smiling really does make you feel happy. So imitation can act as a kind of tutorial on emotion. I see someone smile, so I smile myself. Then I feel happy inside and I assume they do too. That means for babies imitation is both a symptom of innate empathy and a tool to extend and elaborate that empathy.
"…. Wherever empathy comes from neurologically, you can imagine how it might motivate moral behavior. If witnessing another person’s pain literally feels painful to a baby, he might act to try to alleviate that pain as he would act to alleviate his own misery. If witnessing joy makes him joyful, he might try to bring about that joy in others. This might seem like a rather selfish basis for altruism - I ease another’s pain because it makes me feel better.
"But there is another way that empathy might motivate altruism. It’s possible that babies literally don’t see a difference between their own pain and the pain of others. Maybe babies want to end all suffering, no matter where it happens to be located. For them, pain is pain and joy is joy. Moral thinkers from Buddha to David Hume to Martin Buber have suggested that erasing the boundaries between yourself and others in this way can underpin morality. We know that children’s conception of a continuous separate self develops slowly in the first five years.
"Of course, as adults, parents do have a strong separate sense of self - a sense that usually distances us from others. But that sense dissolves in our interactions with babies. Parents are on the other side of those intimate early face-to-face interactions. And it sure doesn’t feel as if we react to our baby’s pain simply because we want to feel better ourselves. Instead, the pain just pulls on our heart strings directly. I literally feel my baby’s pain with as much intensity as I feel my own pain. The impulse to soothe my baby is just as automatic and immediate as my impulse to soothe myself. The immediate, intimate, loving interactions between babies and adults dissolve the boundaries between the self and others. It may feel that way for the babies, too."
Rules vs harm
"In a groundbreaking study, Judith Smetana presented children as young as two and a half with simple, everyday scenarios. In some of the stories children broke a preschool rule - they didn’t put their clothes in the cubby or they talked at naptime. In others, they caused real physical or psychological harm to another child, by hitting, teasing, or stealing a snack. Smetana asks the children how bad the transgressions were, and whether they deserved punishment. But, most important, she asked whether the actions would be OK if the rules were different or if they took place in a school with different rules. Would it be OK to talk at naptime if the teachers all said so? Would it be OK to hit another child if the teachers said so?
"Even the youngest children differentiated between rules and harm. Children thought that breaking rules and causing harm were both bad, but that causing harm was a lot worse. They also said that the rules could be changed or might not apply at a different school, but they insisted that causing harm would always be wrong, no matter what the rules said or where you were."
Rules vs logic
"Children understand normative rules better than they understand logic. Logical reasoning involves "if P then Q" deductions. Suppose Jane says, "When I go outside (P) I wear my hat (Q)." Then you show children four pictures: (1) Jane outside and wearing a hat (P, Q); Jane outside and not wearing a hat (P, not Q); (3) Jane inside and wearing a hat (not P, Q); and (4) Jane inside and not wearing a hat (not P, not Q). You ask them to choose the picture where "Jane is not doing what she said." Logically the correct answer is 2. But children are quite bad at this kind of reasoning - they tend to pick by chance.
"However, children do much better if you ask them to reason about rules. Suppose Jane’s mom says "If you go outside you must wear your hat." Then the child sees the same four pictures as before. But this time she has to choose the picture where "Jane was being naughty and not doing what she is supposed to do." Once again the right answer is 2, Jane standing out there in the cold risking her death without a hat. Even three year olds are very good at picking out the rule violation. Moreover, young children in Nepal and in Colombia are as good at rule logic as children in the United States and Britain."
Intentions and judgments about good and harm
"One-year-olds already understand human intentions and differentiate intentional and unintentional actions. In one experiment, an adult played a game with a baby in which he gave the baby toys across a table. Occasionally, the adult held up a toy but didn’t give it to the baby. Sometimes he just refused to hand it over. But sometimes he seemed willing to hand it over but was held up by circumstances that were beyond his control - for example the toy was in a transparent box that he couldn’t open. Nine- to eighteen-month-olds were more impatient and fussy when the adult willfully kept the toy for himself than when he tried to give them the toy but just couldn’t manage it.
"By the time they’re three, children consider intentions when they make basic moral judgements about good and harm. They say that intentionally pushing another child is bad, but it’s OK if you just accidentally bump into them. They also differentiate between intentional and accidental rule-breaking. Remember the study that looked at children’s early normative logic, where Mom said Jane had to wear a hat outside. The experimenters also asked whether the child was naughty if "she’s outside and the wind’s blown her hat off" and "she’s outside and she’s taken her hat off." The youngest children they tested, who were only three, distinguished the two cases. They said the child who broke the rule on purpose was much naughtier than the child who broke the rule accidentally."
Intelligence and long childhoods
This quote comes from Alison Gopnik’s TED talk.
"If we look across many, many different species of animals, not just us primates, but also including other mammals, birds, even marsupials like kangaroos and wombats, it turns out that there’s a relationship between how long a childhood a species has and how big their brains are compared to their bodies and how smart and flexible they are.
"And sort of the posterbirds for this idea are the birds up there. On one side is a New Caledonian crow. And crows and other corvidae, ravens, rooks and so forth, are incredibly smart birds. They’re as smart as chimpanzees in some respects. And this is a bird on the cover of science who’s learned how to use a tool to get food. On the other hand, we have our friend the domestic chicken. And chickens and ducks and geese and turkeys are basically as dumb as dumps. So they’re very, very good at pecking for grain, and they’re not much good at doing anything else. Well it turns out that the babies, the New Caledonian crow babies, are fledglings. They depend on their moms to drop worms in their little open mouths for as long as two years, which is a really long time in the life of a bird. Whereas the chickens are actually mature within a couple of months. So childhood is the reason why the crows end up on the cover of Science and the chickens end up in the soup pot."
Here is a time-line of the experiments above.
White ball/red ball probability test
Babies look longer when an experimenter pulls out mostly red balls from a ball they have seen to contain mostly white balls.
Head-tapping on box imitation test
A week after seeing an experimenter tap his head on a box to make it light up, a one year old will imitate.
Experimenting with imitation
In an experiment where an adult mimicked a baby’s gestures, one year olds produced exaggerated gestures seemingly to see if the experimenter would mimick those.
In an experiment, one-year-olds were more fussy when an experimenter could give them a toy but didn’t vs trying to give them a toy, but being unable to because the toy was in a transparent box.
Broccoli and goldfish test
Children can understand that an experimenter prefers broccoli to goldfish crackers.
Gopnik is contrasting 15 month olds vs 18 month olds when talking about the rake task, and it’s possible that 18 months is when babies can solve the rake task.
More sophisticated head tapping on box test
Children will not tap their heads on the box if the experimenters’ arms were wrapped in a blanket when he was tapping his head head on the box. They will use their hands instead.
Recognizing themselves in the mirror
Babies start to recognize themselves in the mirror. This quote is not in the post above. “For example, when they get to be around eighteen months old, children start to recognize themselves in the mirror. You can show this by surreptitiously putting a sticker on the baby’s forehead and then putting her in front of a mirror. One-year-olds act as if there is another baby in the mirror and they point to the image of the sticker in the mirror. Two-year-olds, in contrast, immediately touch their own foreheads to see if the sticker is there.”
Two and a half
Rule vs harm test
Two and a half year old children know that it would be ok to talk at naptime if the teachers said so, but it wouldn’t be ok to hit a child if the teachers said so.
Delayed cookie test
Children get better at the two cookies if you wait a few minutes test between the ages of three and five.
When asked what Ellie was thinking about, preschoolers will say the children in the picture, the frame, but not the chair in the next room.
5 year olds
Children get better at knowing how they acquired a piece of information: by being told it, by seeing it, by being given a clue etc.