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Nudging Kids Into Wonder—Then Science

They never met, Rachel Carson and Cecilia Cruz.

Diptych of portrait of Rachel Carson and an illustration of Celia Cruz
(Left) Photograph by CBS Photo Archive, Contributor, Getty (Right) Illustration detail by Gavin Aung Than, Zen Pencils

Cecilia, as you’re about to learn, is a little girl who lives indoors. She doesn’t get out much, doesn’t want to, but she has a mom, and that mom coaxes her out the door, across the yard and onto a beach that looks….. totally empty, totally boring—and then, something happens. Something extraordinary.

Actually, reading this cartoon strip, two amazing things happen, or happened to me. The words come from Rachel Carson, the famous marine biologist and author of the world-changing Silent Spring. The text is only 340 or so words, lifted from an essay she wrote about taking her little nephew to explore woods and beaches. It’s about childhood wonder.

The opening spread of Rachel Carson's ''The Sense of Wonder''
Photograph by Becky Harlan

Carson writes well enough, but for me the real kick comes from Gavin Aung Than’s pictures. He’s an Australian illustrator, and he doesn’t change a word. But he improvises. Instead of a boy, Than draws a girl, an imaginary “Cecilia.” He substitutes the girl’s mother for Carson. And instead of woods and shells, he gives Cecilia a moment on the beach that thrills her and changes her life.

None of the scenes drawn here were in Carson’s head, but what Than has imagined is the graphic equivalent of a movie score—he enhances, he underlines, and every so often he gives her words a crazy, topsy-turvy joy. Maybe you’ll disagree. Why don’t you to take a look?

Comic illustrating words by Rachel Carson about encouraging a sense of wonder in children

Comic illustrating words by Rachel Carson about encouraging a sense of wonder in children
Comic by Gavin Aung Than, Zen Pencils

Than does a lot of these illustrated passages. His blog is called Zen Pencils. A few years ago, he was toiling away in an Australian ad agency, hating his job, hating his days, and I don’t know what broke him, but finally he said “enough,” sold his house, resigned his job, and decided to throw himself into this project, taking quotations (from presidents, scientists, statesmen, writers, celebrities) and annotating them with drawings. Now it’s a pair of books.

What he does is not translation; there’s nothing literal about his strips. He’s inventing, augmenting, reshaping. In the Carson passage, the mother worries that she doesn’t know enough to teach her child true things about nature. “It is not half so important to know,” Carson writes, “as to feel.”

So how does he sell that line? He shows us, wordlessly, all these little turtles heading off to sea, lit by a rising sun. Feelings follow. Later, he gives Cecilia a 500-pound swimming companion to keep her company. Yes, it’s sentimental. But hey, he’s got a brush in his hand, a mood in his head, and he knows how to make us see what those sentences are saying. Or what he thinks those sentences are saying.

As Carson suggests, science is a discipline. It needs data, numbers, replication, pattern. But to get there, to get started, scientists need astonishment, mystery, and an intuitive feel for beauty. So feelings matter. And Gavin Aung Than has a feel for feelings.

As good as the Rachel Carson strip is, I think my all-time favorite is Than’s take on a passage by Loony Tunes cartoonist Chuck Jones (of Elmer Fudd and Bugs Bunny fame) talking about his first few (horrible) days in art school, which was a total nightmare until his uncle gave him some simple, cool advice. This involves dancing. Much dancing. You’ll find it here.

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Math For Babies

Doing math is thought to be a uniquely human skill. We can learn the abstract concept of a number: two things or three things or four things; we can represent that concept symbolically (2, 3, 4); and we can use those symbols to understand more complex abstractions (2*3^4).

We’re not born with these abilities, but we do seem to be born with a general sense of number. A few years ago, researchers played newborn infants — as young as seven hours! — recordings of spoken syllables repeated a fixed number of times. In one trial, babies would hear “tuuuuu” four times, for example, whereas in another they’d hear “tu” twelve times. At the same time, the babies were shown pictures of geometric shapes, such as four squares or twelve circles. Somewhat amazingly (at this age, after all, they’re basically blind, sucking potato sacks), the babies matched the number of sounds they heard with the number of shapes they saw. On the trials where they had heard four syllables, they would look longer at pictures of four shapes, and on those with 12 syllables, they’d look longer at pictures of 12 shapes.

Those findings suggested that people have an innate sense of number — or, as cognitive scientists call it, an “approximate number system,” or ANS. Many researchers have argued that the ANS serves as a foundation for learning how to count and do more complicated math later on. That idea makes intuitive sense, but it has been challenging to prove because so many things influence math skills, including general intelligence, language ability, and educational experiences.

“Because children learn number words and symbols so early, it was always hard to say whether symbolic number knowledge was influencing ANS precision or vice-versa,” notes Gavin Price, a cognitive neuroscientist at Vanderbilt University.

That tricky issue is clearer now, experts say, thanks to a study out yesterday in the Proceedings of the National Academy of Sciences. The researchers found that the better a baby’s number sense at 6 months old, the stronger her mathematical abilities three years later. What’s more, the relationship held after controlling for general intelligence. “It’s a huge contribution to the literature,” says Price, who was not involved in the work.

The study hinges on a method in which researchers track babies’ eye movements as they watch two video screens at the same time. One screen always shows the same number of dots, but the dots change in size and location. The other screen shows the same thing, except that the number of dots changes as well. Here’s a short video of one of the trials; the screen on the right always shows 10 dots whereas the one on the left toggles between 10 and 20 dots (warning: utterly adorable baby coming):

Babies like novelty. In an earlier study using this method, the researchers showed that 6-month-old babies tend to look longer at the screen in which the number of dots changes (the left side of the video above) than the other screen, presumably because they notice the difference in the number of dots and like watching it change. “In the video, you can see the baby at the beginning really testing it out, looking back and forth at both of the screens to figure out what’s going on. Then he hones in on the one that’s changing,” says Ariel Starr, a graduate student in Elizabeth Brannon’s lab at Duke University, who carried out the new work.

Three years after the babies watched the videos, Starr’s team brought 48 of them back in the lab for a series of tests measuring their math skills (including their ability to count, identify numbers, compare the size of numbers, and do basic calculations) and general verbal and non-verbal intelligence. Babies who had strongly preferred to look at the changing number of dots at 6 months tended to have higher math scores at 3 years than did babies who had a weaker number sense. That was true even after the researchers corrected for intelligence scores.

“To me this is interesting because it suggests that this pre-verbal, primitive, quantitative ability seems to be foundational for acquiring more uniquely human symbolic math capabilities,” Starr says. “It really seems to be a building block.”

Still, she adds, the correlation was modest: “I can’t tell you what your baby’s SAT scores are going to be.” It’s also clear from past work that other cognitive skills, notably working memory and attention, influence math ability. How our early sense of number may interact with those abilities across development is still a mystery.

The connection between early number sense and later math skill seems to be strongest for infants that have either extremely high or extremely low scores in the dot test, notes Daniel Hyde, assistant professor of psychology at the University of Illinois at Urbana Champaign. “This method may be best suited for identifying early propensities to excel or struggle in math class and less predictive for those that fall in the middle.”

More provocatively, the study also suggests that boosting babies’ number sense could influence their math development, Hyde says. In line with that idea, this past weekend, at the meeting of the Cognitive Development Society in Memphis, Brannon’s group reported that training first and second graders on non-symbolic approximation tasks ups their scores on symbolic arithmetic tests. “This might be a way to help boost numerical competence in young children who are struggling at math, or even preschool children before they have a chance to fall behind,” Starr says.

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“Kangaroo Mothers” and the Power of Touch

In the early 1980s, two pediatricians in Bogota, Colombia, made waves around the world for a new method of caring for premature babies. The method, called Kangaroo Care, was so named because of how it resembles marsupial caregiving: A mother snuggles her baby, upright, against her bare chest for long periods of time.

The doctors developed the program in 1979 at the Instituto Materno Infantil at San Juan de Dios Hospital in Bogota. This large maternity hospital was overcrowded and understaffed and underfunded: In the special baby care unit, several babies would often share the same incubator. Infection rates were sky-high, as were abandonment rates and death rates.

To improve this dire situation, doctors Edgar Rey and Hector Martinez launched a program to get babies out of the hospital — and its germs — as soon as they were physically stable, even if they were still very small. They advised mothers to keep their baby on their chest for warmth, and to exclusively breast feed.

Rey and Martinez reported mortality rates of the 539 babies who went through this home care between 1979 and 1981. The smallest babies — those weighing between 501 and 1,000 grams — showed 72 percent survival rates, compared with 0 percent survival with the hospital’s conventional care. Nearly 90 percent of babies between 1,001 and 1,500 grams survived at home, compared with 27 percent in the hospital. And the number of babies abandoned dropped by two-thirds.

These results never appeared in a medical journal, and they are somewhat inflated because they didn’t include deaths of babies who died in the first few days of life. Nevertheless, this very appealing idea — that a mother’s touch could save her child’s life — made headlines all over the world, and UNICEF endorsed the program whole-heartedly.

People in developed countries were eager to try the new method, too, even though they didn’t have any of the problems of a strapped hospital in Colombia. Many doctors were skeptical that Kangarooing would provide much benefit in rich countries, beyond making moms and dads feel better about the experience. As two British doctors wrote in a Lancet paper — titled “Myth of the Marsupial Mother” — in 1985: “Colombia has nothing to teach developed countries about improving survival of [premature] babies but may yet help us to heal some of the psychological problems incurred by modern neonatal care.”

PAHO/WHO, via Flickr
PAHO/WHO, via Flickr

In the three decades since, those Colombian researchers and many other groups have published randomized, rigorous studies of Kangaroo Care, and experts continue to debate whether, and under what circumstances, it does any good. In 2011, the prestigious Cochrane Collaboration published a comprehensive review of all of the major studies to date, and seemed to confirm what Rey and Martinez had originally claimed: In resource-limited settings, Kangaroo Care significantly lowers the risk of infection, hypothermia, and death. It also increases a baby’s weight and head circumference, and the strength of the maternal bond. It’s unclear, though, whether the method’s positive effects last through a baby’s adolescence, nor whether it offers much for premature babies in developed countries.

I write this protracted introduction as a caveat to two new papers reporting that, in Colombia and Israel, respectively, the positive effects of Kangaroo Care can last for more than a decade after a baby’s birth. The studies are fascinating to me because they’re suggesting that a mother’s touch can exert a powerful influence on her child’s brain development (wow! how?). But it’s also possible, given the spotty data, that the positive effects aren’t coming from her touch, per se. So, with caveat said, on to the new studies.

The first was done by a group of Colombian and Canadian researchers who have been advocating for Kangaroo Care since the beginning. They measured brain activity of 48 teenagers in Colombia: 39 born very prematurely and 9 born at term. Of the premature group, 21 had received Kangaroo Care and 18 had received standard hospital care.

The researchers used transcranial magnetic stimulation, or TMS, in which researchers place a wand on the participant’s head. The wand contains a magnetic coil, which produces an electromagnetic pulse that passes through the person’s skull and tickles the neurons underneath. The neurons respond to that pulse, and the researchers then measure that neuronal response via EEG electrodes placed all over the scalp.

In this case, the researchers placed the wand over participants’ motor cortex, on the center of the top of the head, which is involved in motor planning. Teenagers who were born prematurely and received Kangaroo Care showed brain-wave patterns that were similar to the kids born to term, according to the study, published last year in Acta Paediatrica. In contrast, the kids born prematurely who had had standard hospital care showed a slower synchronization of brain activity.

The second study, based at a hospital in Israel, also looked at adolescents who had been born too early: 73 who had received Kangaroo Care and 73 who had been given standard incubator care. As published last week in Biological Psychiatry, the researchers found that by 10 years old, the Kangaroo babies had better responses to stress, more regular sleeping patterns, and scored higher on tests of cognitive development compared with the kids who had received standard preemie treatment.

If we assume (and, again, see caveat above) that these benefits are the direct result of skin-to-skin contact between a baby and her mother, then what could explain that?

Nobody knows for sure, but scientists have learned a lot by studying the interactions between baby rodents and their mothers. For example, early physical contact with mom affects the expression of genes related to stress hormones and social behavior in the baby animal’s brain. Conversely, depriving an infant rodent (or infant human, for that matter) of its mother leads to all sorts of behavioral and medical problems for the rest of the animal’s life. “Being a mammal therefore implies that the brain is not fully formed at birth, and maturation of systems that enable adaptive functioning in the world are gradually acquired through close contact with an alert, responsive mother,” write the authors of the new Biological Psychiatry study.

These studies of mother-baby interactions — and the descriptions of these studies in the popular press — tend to focus on these chemical mechanisms of how a mother’s touch and attention help her baby thrive. (There’s this thing called oxytocin…) What sometimes gets overlooked, though, is that this is not a one-way phenomenon. As a mother touches and influences her baby, so too does the baby touch and influence her mother. It’s the constant, back-and-forth interaction that creates the bond, and the bond that keeps a mother invested in her child’s success for many years to come.

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On Learning Animal-ness

What is an animal?

It’s a surprisingly difficult question, if you really think about it. Here’s Merriam-Webster’s definition:

any of a kingdom (Animalia) of living things including many-celled organisms and often many of the single-celled ones (as protozoans) that typically differ from plants in having cells without cellulose walls, in lacking chlorophyll and the capacity for photosynthesis, in requiring more complex food materials (as proteins), in being organized to a greater degree of complexity, and in having the capacity for spontaneous movement and rapid motor responses to stimulation


But any 4-year-old knows what an animal is, and she certainly doesn’t define it in terms of cells or proteins or degrees of complexity. So how, then, do humans develop this understanding of animal-ness?

According to a weird and fascinating new study, babies expect animals to not only exhibit certain behaviors (like intentional movements) and have particular physical features (like fur), but also to have guts. I mean that literally: Babies apparently find it odd to see an animal that’s hollow.

The study focused on 8-month-old babies, far too young to talk. Like a lot of research on pre-verbal infants, this one gauged what the babies were thinking by measuring how long they looked at an array of objects. When babies see something surprising, they tend to look at it longer than something they were expecting to see.

The researchers, led by Renée Baillargeon of the University of Illinois at Urbana-Champaign, presented the babies with many kinds of toys. Some were furry, some were smooth. Some of the toys moved by themselves, such as a can that bounced across the floor. Some were “agentive”, such as a can that quacked to start a “conversation” with one of the researchers.

After the babies had familiarized themselves with all of the toys, the researchers then picked up and rotated the objects, revealing that some of them were hollow. The babies looked significantly longer — as if to say, Umm, what?! — at toys that were self-propelled, agentive, and hollow than they did at toys that were self-propelled, agentive, and not hollow. They didn’t have this reaction to toys that were only self-propelled and hollow, or only agentive and hollow.

The researchers also wanted to test whether insides mattered with furry toys. Other studies had suggested that by 7 months old, infants start using fur as a clue that an unfamiliar object is an animal that might be expected to move on its own. The new study also measured the infants’ looking times after showing them a can covered in brown beaver fur compared with a box covered in tan paper. The babies looked longer at the can when it was furry, self-propelled, and hollow than when it was furry, stationary, and hollow. And they didn’t seem to care if the box, whether moving or stationary, was hollow.

The researchers interpret these findings to mean that infants expect animals, in particular, to have insides, but don’t have that expectation for other objects. They say this bolsters something called the “innards principle,” first proposed by Baillargeon’s co-author, Rochel Gelman, in 1990. The innards principle says that we are born with the notion that things that move by themselves must have something inside of them to facilitate that motion.

Lots of research on toddlers and children has lent support to the innards principle. One 1995 study found, for example, that children younger than 8 expect the insides of animals to be different than the insides of machines. Kids also seem to understand that animals need their insides to function: Kindergarteners know, for example, that a dog can’t bark if it loses its insides, and that animals need to eat and drink to keep their insides working properly. The new study, though, is the first to show that an understanding of so-called “vitalistic biology” or “folk biology” appears at a very young age.

By Don Burkett, via Flickr

To me, the strangest thing about the innards principle is that infants seem to recognize that animals have insides without having any specific knowledge about what, exactly, is in there. As Frank Keil of Yale University pointed out in a commentary about the study published this week, if infants know anything about insides, it would be about non-animal ones: “The average infant has minimal firsthand experiences with road kill, surgical dissections, slaughterhouses, or other graphic displays of animal interiors,” Keil writes. “In fact, they would be expected to surely have far fewer of such experiences than for many simple devices and toys that they can be quite skilled at breaking open.”

So what, then, could explain the innards principle (assuming it’s true)? How would this odd and specific skill have evolved?

The researchers put forth several possible explanations, but the one I like best boils down to predators and prey. Both predators and prey are animals, and they have exerted a pretty powerful selective pressure over the course of human evolution: If we don’t recognize a predator, we die, and if we don’t recognize prey, we die.

“It seems plausible that the human mind would have evolved an abstract expectation that animals have filled insides,” the authors write. “Damaging the insides of a predator or prey brings about its demise, and consuming these insides provides valuable nutrients.”

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When Do Kids Understand Death?

Wednesday morning I went to the funeral of my husband’s grandfather, who had lived 93 years. As a couple of dozen family members circled around his grave site, I couldn’t help but think of how bizarre and disorienting death is. Just a few days earlier, there was, there existed, a physically robust, smiling, warm, breathing man. And now his big body was somehow fixed in a wooden box, descending into a dirt hole just a few feet from his tearful widow, children, grandchildren, and great-grandchild.

My niece Emily, who’s almost 3, was on her mom’s hip, snacking on Cheerios and watching the burial intently. “What are we doing?” she said. “Saying good-bye to Opa,” her mom whispered. “Bye-bye, Opa!” Emily said cheerily. Her mom burst into tears. “What’s wrong, Mommy?”

It was one of the morning’s many bittersweet moments, a reminder that even amidst death, life goes on. I kept thinking about it throughout the day, as I saw Emily laughing and climbing and running around an apartment full of grievers. When does a child learn the concept of death? And how do scientists even figure that out?

Turns out that psychologists have been investigating children’s ideas of death since the 1930s. When judged through a modern lens, some of these early studies seem a bit wacky. In the first, published in 1934, doctors interviewed boys living in Bellevue Psychiatric Hospital in New York. As part of the interview, they recorded the boys’ responses after a doll fell to the ground with a loud noise.

One of the most famous early studies was done by Hungarian psychologist Maria Nagy. She interviewed nearly 400 children living in Budapest just after World War II, a time when death was everywhere. She simply asked them to answer, either in words or pictures, “What is death?”

Just one study looked at this topic in the 1950s, followed by eight in the 60s and two dozen in the 70s. Almost all of these studies, according to a fascinating review published in 1984, relied on interviews with children. Some, like Nagy’s, asked open-ended questions, whereas others were more specific, asking things like, Can a dead person come back to life? Can you think of someone who might not die? Will you die?

No matter what your age, death is not easily defined. But for the purposes of research, scientists define a child’s understanding of death by looking at three specific aspects of the concept.

The first is death’s irreversibility. Once your body is dead, it cannot ever be alive again. Kids under 3 don’t understand this idea; they’ll talk about dead people as if they went on a trip or took a nap, or will hold open the possibility that dead things can come back to life with the help of water, food, medicine, or magic. Children begin to grasp death’s finality around age 4. In one typical study, researchers found that 10 percent of 3-year-olds understand irreversibility, compared with 58 percent of 4-year-olds.

The other two aspects of death are learned a bit later, usually between age 5 and 7. One, dubbed ‘nonfunctionality’, is the idea that a dead body can no longer do things that a living body can do. Before this is grasped, kids will affirmatively answer questions like, Can a dead person feel? or If someone died, could he still eat? Can he move? Can he dream?

Then there’s death’s most befuddling attribute, at least for me: its universality. Every living thing dies, every plant, every animal, every person. Each one of us will someday expire. Interestingly, before children learn this, many believe that there are certain groups of people who are protected from death, like teachers, parents, and themselves. “Without a doubt, most children understand that some people die before they understand that they themselves will die,” the review authors write. And even children who understand that they will one day perish “have a tendency to say that their death will occur only in the remote future when they get old.”

These are all generalities and tendencies. Some kids develop more quickly than others. And some studies have found that emotionally traumatic events — such as the loss of a parent — can speed up a child’s understanding of death.

This research helps explain my niece’s reaction at the funeral. But it’s strange to simplify death as if it were any other early cognitive concept, like object permanence or theory of mind. I’ve got 26 years on my niece and still haven’t hit the developmental milestone of understanding death. I doubt I ever will.

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Infants prefer a nasty moose if it punishes an unhelpful elephant

If you saw someone punching a stranger in the street, you might think poorly of them. But if you found out that the stranger had slept with the assailant’s partner, had kicked a kitten, or was Justin Bieber, you might think differently about the situation. You might even applaud the punch-thrower.

When we make moral judgments, we do so subtly and selectively. We recognise that explicitly antisocial acts can seem appropriate in the right circumstances. We know that the enemy of our enemy can be our friend. Now, Kiley Hamlin from the University of British Columbia has shown that this capacity for finer social appraisals dates back to infancy – we develop it somewhere between our fifth and eighth months of life.


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Children share when they work together, chimps do not

We are a cooperative ape, and a fair one. We work together to put food on the table and once it’s there, social rules compel us to share it around equitably. These two actions are tied to one another. In a new study, Katharina Hamann from the Max Planck Institute for Evolutionary Anthropology has shown that three-year-old children are more likely to fairly divide their spoils with other kids if they’ve worked together to get them.

The same can’t be said of chimpanzees, one of our closest relatives. Sharing comes less naturally to them, and it doesn’t become any more likely if they’ve worked together to get a meal.


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Self-control in childhood predicts health and wealth in adulthood

“Control! Control! You must have control.” – Yoda

Pay attention. Put that down. Stop doing that. Eat that later. Would you, just, behave? These phrases are a familiar part of family life, as parents try to drum a sense of self-control into their children. Right from the start, they are taught to restrain their impulses, focus on their goals, and control their choices. This seems like a wise move, but how could you tell if such instruction actually affects a child’s fate?

Ideally, you would follow a group of children into adulthood, to see how their degree of self-control affects the course of their lives. You’d need to catch up with them at regular intervals to look at their health, mental state, finances and more. You’d need to meticulously plan the study decades before the important results came in, and you’d need to keep in close touch with the volunteers so they stick with the study. In short, you’d need to have set up the Dunedin Multidisciplinary Health and Development Study.

The Dunedin Study was the brainchild of Phil Silva, and its wide-ranging team include  Terrie Moffit and Avshalom Caspi, a husband and wife duo who work at Duke University and King’s College London. The study began way back in 1975, with 1037 children who were born in Dunedin, New Zealand between April 1972 and March 1973. The researchers became their occasional companions through most of their lives, up till the age of 32. At 11 separate points, Moffit and Caspi measured the recruits’ health, wealth and more. And amazingly for a study of this sort, 1014 of the children are still alive and involved.


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The dark side of oxytocin, much more than just a “love hormone”

MotherThere’s a chemical that can subtly shift your childhood memories of your own mother. In some people, it paints mum in a more saintly light, making them remember her as closer and more caring. In others, the chemical has a darker influence, casting mum as a less caring and more distant parent.

All of this becomes heavily ironic when you consider that the chemical in question – a hormone called oxytocin – is often billed as the “hormone of love”, and even marketed as “Liquid Trust”. As a new study shows, the reality is much more complicated. Describing oxytocin as the “hormone of love” is like describing a computer as a “writing tool” – it does other things too, some of which aren’t pleasant.


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Newborn babies have a preference for the way living things move

Running_rabbitThis is an old article, reposted from the original WordPress incarnation of Not Exactly Rocket Science. I’m travelling around at the moment so the next few weeks will have some classic pieces and a few new ones I prepared earlier.

From an animal’s point of view, the most important things in the world around it are arguably other animals. They provide mates, food, danger and companionship, so as an animal gazes upon its surroundings, it needs to be able to accurately discern the movements of other animals. Humans are no exception and new research shows that we are so attuned to biological motion that babies just two days old are drawn to extremely simple abstract animations of walking animals.

Animals move with a restrained fluidity that makes them stand out from inanimate objects. Compared to a speeding train or a falling pencil, animals show far greater flexibility of movement but most are nonetheless constrained by some form of rigid skeleton. That gives our visual system something to latch on to.


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You are what you eat – how your diet defines you in trillions of ways


We depend on a special organ to digest the food we eat and you won’t find it in any anatomy textbook. It’s the ‘microbiome’ – a set of trillions of bacteria living inside your intestines that outnumber your own cells by ten to one. We depend on them. They wield genes that allow them to break down molecules in our food that we can’t digest ourselves. And we’re starting to realise that this secret society within our bowels has a membership roster that changes depending on what we eat.

These changes take place across both space and time. Different cultures around the world have starkly contrasting diets and their gut bacteria are different too. As we grow older, we eat increasingly diverse foods, from the milk of infancy to the complex menus of adulthood. As our palate changes, so do our gut bacteria.


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Baby’s first bacteria depend on route of delivery


They are mum’s first gift to her newborn baby on the day of its zeroeth birthday – bacteria, fresh from her vagina. Vaginal bacteria are among the trillions of microscopic hitchhikers that share our bodies with us. Collectively known as the ‘microbiota’, these passengers outnumber our own cells by ten to one. Children partly inherit their microbiota from their mothers. During birth, they pass from the largely bacteria-free conditions of the womb through the microbe-laden vagina into the equally bacterial outside world.

Being slathered in vaginal microbes might not seem like much of a treat from our adult perspective, but to a newborn, it’s a key event. The microbiota are important partners, influencing our physiology and our risk of disease. Now, Maria Dominguez-Bello from the University of Puerto Rico found that the way we enter the world determines the identities of our first bacterial colonisers. Babies delivered by Caesarean section end up with a very different portfolio to those who are born naturally.


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New Nicaraguan sign language shows how language affects thought

NicaraguaOne of the signs for “Nicaragua”. Photo by Ann Serghas

In the 1970s, a group of deaf Nicaraguan schoolchildren invented a new language. The kids were the first to enrol in Nicaragua’s new wave of special education schools. At first, they struggled with the schools’ focus on Spanish and lip-reading, but they found companionship in each other. It was the first time that deaf people from all over the country could gather in large numbers and through their interactions – in the schoolyard and the bus – Nicaraguan Sign Language (NSL) spontaneously came into being.

NSL is not a direct translation of Spanish – it is a language in its own right, complete with its own grammar and vocabulary. Its child inventors created it naturally by combining and adding to gestures that they had used at home. Gradually, the language became more regular, more complex and faster. Ever since, NSL has been a goldmine for scientists, providing an unparalleled opportunity to study the emergence of a new language. And in a new study led by Jennie Pyers from Wellesley College, it even tells us how language shapes our thought.

By studying children who learned NSL at various stages of its development, Pyers has shown that the vocabulary they pick up affects the way they think. Specifically, those who learned NSL before it developed specific gestures for left and right perform more poorly on a spatial awareness test than children who grew up knowing how to sign those terms.


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The development of fairness – egalitarian children grow into meritocratic teens

Children_fairnessTwo children, Anne and Carla, have worked together to make a cake and they have to split it between them. Anne says that she’s the bigger cake aficionado and deserves the lion’s share. But Carla demands the bigger slice since she did most of the cooking. A nosy third party, Brenda, argues that the only fair call would be for the two girls to split the cake equally. Which is the right path?

There’s no obvious right answer and different people will probably side with different viewpoints. Dilemmas like this have been the subject of much philosophical debate, and they’re a common part of everyday life. How do you allocate pay rises between your staff? How should the UK’s new government split its budget among its various departments?

According to Norwegian scientist Ingvild Almås, our attitudes to such questions change during our childhood and adolescence, as we start changing our opinions on what counts as ‘fair’. Children tend to shun any form of inequality – they’d agree with Brenda. But as they enter the turmoil of adolescence, they become more meritocratic and are happier to divide wealth according to individual achievements, as Carla suggested. As their teens draw to a close, they (like Anne) pay greater heed to efficiency, making choices of maximum benefit to the group.


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Williams syndrome children show no racial stereotypes or social fear

People with Williams syndrome are some of the friendliest people you’ll ever meet. They are incredibly sociable, almost unnervingly so, and they approach strangers with the openness that most people reserve for close friends.

Their sociable streak is the result of a genetic disorder caused by the loss of around 26 genes. This missing chunk of chromosome leaves people with a distinctive elfin face, a risk of heart problems, and a characteristic lack of social fear. They don’t experience the same worries or concerns that most of us face when meeting new people. And now, Andreia Santos from the University of Heidelberg has suggested that they have an even more unique trait – they seem to lack racial bias.

Typically, children start overtly gravitating towards their own ethnic groups from the tender age of three. Groups of people from all over the globe and all sorts of cultures show these biases. Even autistic children, who can have severe difficulties with social relationships, show signs of racial stereotypes. But Santos says that the Williams syndrome kids are the first group of humans devoid of such racial bias, although, as we’ll see, not everyone agrees.

Santos compared the behaviour of 20 white children with Williams syndrome, aged 7 to 16, and 20 typical white children of similar backgrounds and mental ages. To do so, she used a test called the Preschool Racial Attitude Measure (PRAM-II), which is designed to tease out traces of gender or racial biases in young children.