On a hot Friday in August, neuroscientist Sam Wang is about to flee the ­basement of Princeton’s molecular biology department for a family vacation, after spending most of the morning ­advising graduate students who were studying the brains of mice that run on treadmills. But before he can escape, he must complete one last bit of brain research: hanging out with his 4-year-old daughter, Vita.

This undertaking comes at the request of a reporter. Wang, along with science writer Sandra Aamodt, is the ­co-author of Welcome to Your Child’s Brain: How the Mind Grows from Conception to College, released in September by Bloomsbury USA. The book contains all sorts of ­cocktail-party morsels that will keep parents and expectant parents buzzing, such as: Breastfeeding has little demonstrated influence on a baby’s later intelligence; ­children who practice self-control are more empathetic and show less anger and fear; and babies of depressed pregnant women grow up more vulnerable to stress.

Their new book is a sequel to their 2009 offering, Welcome to Your Brain: Why You Lose Your Car Keys but Never Forget How to Drive and Other Puzzles of Everyday Life, which, by publishing’s standards, was a hit: It has sold more than 170,000 copies worldwide. That book helped catapult Wang (pronounced “Wong”) and Aamodt into The New York Times op-ed pages, where they jointly write occasional essays that tend to go viral. 

In their new book, little Vita pops up as a minor character who likes Mamma Mia show tunes and mimics her dad’s ability to stick his tongue out with the sides curled up. Now it is time to see how a specialist in children’s brains interacts with a child.

His little girl comes rushing in to Wang’s cramped office. He scoops her up for a hug. 

Surrounded by photographs of dog brains and books with titles such as The Axon, Wang sits behind his desk, and she sits in front.

“Vita, could you do something? Will you write me your name?” Wang asks.

Vita scrawls “Ativ” — “Vita” spelled backward. 

Wang’s eyebrows tighten. 

“Vita, what are you doing? You’re writing your name in a crazy way,” he says. 

But just then, Wang’s mind pivots, as if he remembers that he had researched and written about this exact phenomenon in his and Aamodt’s new book: Most children under the age of 5 temporarily experience mirror-image confusion — a state in which the right and left parts of an image are reversed, as if they were reflected in a mirror.

Wang has an idea. He writes Vita’s name spelled backward — “Ativ” — and shows it to his daughter.

“What does that say?” he asks Vita.

She instantly recognizes the word as her own name. “Vita,” she says.

By now, Wang seems comfortable with his daughter’s mistakes. Instead of being concerned as an average parent might have been, Wang is calm and curious. 

To prove his point, Wang does one last experiment. Instead of writing her name backward, he scrambles the letters and writes “Aitv.”

“Is that your name?” he asks, sliding the scrap of paper to her.

Vita laughs. To her, what her father scribbled was a strange word.

“No!” she says. Dad nods and grins. 

Peter Murphy

Wang, 44, an Ohio native and son of Chinese immigrants, has been teaching at Princeton since 2000. He’s an academic wedded to an array of subjects such as synaptic plasticity, the ability of the connections between your brain’s neurons to change strength, appear, or vanish. But Wang also enjoys expanding his wonky material into relatable ideas for mainstream audiences. In June and September, he and Aamodt wrote two popular Times op-eds, based on research from their new book, which explained how children who spend more time outdoors are less likely to be nearsighted and how delaying your child’s entry to kindergarten by a year doesn’t give him or her a leg up with academics in the long term. Three years ago, he penned a controversial USA Today article debunking the comic actress Jenny McCarthy’s argument that vaccines cause autism, a subject revisited in the new book, too. 

While many professors might seem content writing for their peers with niche science-journal articles, Wang, a former college radio disc jockey who speaks with the effusiveness of an actor, likes leveraging his data-driven mind to analyze everyday issues. For the 2004 and 2008 presidential elections, he launched a popular polling blog. He also has given YouTube-viewable lectures at the kind of venues that nowadays certify a person’s intellectual credibility and celebrity: He and Aamodt spoke about their first book at Google’s headquarters; he discussed willpower for a TEDx conference talk in San Francisco; and there he is on the website Big Think, a kind of YouTube for camera-ready intellectuals and professors. 

When he was the chairman of Princeton’s Committee on Public Lectures from 2006 to 2010, Wang took pride in reeling in campus speakers such as Supreme Court Justice Ruth Bader Ginsburg and the pencil-thin-mustachioed filmmaker John Waters, who first gained fame for cult films featuring transvestites like Divine. (Inside Wang’s office, his students can see a poster advertising Waters’ speech on the wall marked with a prominent note from the filmmaker: “To Sam, who made me respectable.”) But most of all, Wang is devoted to neuroscience — and to making neuroscience accessible to the average person. He views his job as a kind of public service: With the latest book, he wants to help parents cast aside the surfeit of myths about child-rearing that have cropped up over the years, including the myths of quickie IQ-boosting tricks. (For starters, playing Mozart to your baby won’t get her or him into the Ivy League.)

Instead, he and Aamodt want Welcome to Your Child’s Brain to serve as a kind of manual for parents that provides understandable and evidence-based facts about child-rearing and brain development. The basic idea: Relax. Your child’s brain “raises itself,” they say in the book, and if you furnish a loving, stable environment, most likely everything will be fine. 

Other ideas in the book, however, are more provocative, such as the breastfeeding tidbit. Wang and Aamodt allow that, yes, children who have been fed exclusively on breast milk during infancy have higher intelligence on average than those who were not. But that’s not necessarily because of the breastfeeding. Parents who breastfeed tend to be richer and more educated, and they are less likely to smoke. 

“Headlines reading ‘Smart Mothers Found to Have Smart Babies’ probably wouldn’t be so memorable,” they say in the book.

This kind of myth-busting makes Wang worry both that he is a sitting duck for parents who think they know better, and that others think he is a parenting oracle with all the answers to raising a Princeton-bound student. 

“I don’t think I have special advice for how someone can get their kid ready to go college,” he says. (Note to readers: Wang and his wife, a doctor, read three stories to Vita each night before she goes to bed.)

“I try to push in my writing that neuroscience is relevant in everyday life, but sometimes I get questions that are very serious, and I recommend that they see a medical specialist,” he says. “One person came to see me last fall after a lecture and said that she was worried about their son on the lacrosse team, who had been checked in the head, and that his mood had changed,” Wang said. “My advice was, ‘Uh, see if he can play tennis?’”

Wang is the grandchild of two men who fought for the Chinese Nationalist Party during the Chinese Civil War in the late 1940s. After the Communists won, his grandparents fled to Taiwan. His parents met in Taiwan and fell in love. In the 1960s, they immigrated separately to the United States to obtain graduate degrees in library science, and got married in Indiana. His father eventually became a librarian at the University of California, Riverside.

Wang, who has two younger siblings, was something of a prodigy. Since his parents were librarians, books surrounded him. His father recognized Wang’s taste for numbers, so he tutored him.

Before he was 8, he was solving advanced math problems. He left Riverside Poly High School without finishing his last two years and enrolled, at 15, at Caltech. Wang wanted to become a scientist, partly to fulfill a dream that his father — who had struggled with English and had to raise three kids — could not attain himself. Wang majored in physics but discovered by his senior year that he loved biology and neuroscience more. After graduating with honors in 1986, Wang immediately began a Ph.D. program in neuroscience at Stanford.

“When I was in fourth grade, someone asked me what I wanted to be, and I said, nuclear physicist. I wanted to figure out the secrets of the universe,” Wang says. “But I found out that in physics, it was taking longer and longer between discoveries. And the selfish reason is that I wanted to be in biology, where I could solve something in my lifetime.”

In the late 1980s, Wang became the news director for Stanford’s radio station KZSU: his first chance to speak and write about science for a general audience — in this case, commuters in their cars. At KZSU, he interviewed Edward Teller, the hydrogen-bomb inventor, then living in the Palo Alto area. Wang remembers asking Teller about J. Robert Oppenheimer, the father of the atomic bomb. The Cold War rivals had a falling out after Teller left to work on the hydrogen bomb and later testified against Oppenheimer during congressional hearings that focused on that scientist’s suspected Communist ties.

“Teller was terrifying. We talked about the Star Wars program and his relationship with it. Then I brought up Robert Oppenheimer, and he got very angry about it. He said, ‘I don’t want to talk about that. This interview is over,’” Wang recalls. “We were live! I spent a few minutes talking him down. Then he was calm.” 

After receiving his Ph.D. in 1994, Wang completed a postdoctoral fellowship at Duke University, where he studied chemical changes in the brain and signals that neurons use to drive learning. Then he landed a job in New Jersey as a postdoctoral technical staff member researching learning and memory mechanisms at Bell Labs, where the transistor and laser, among other innovations, first were developed. But Wang wanted to teach and do research. In 2000, he heard of an opening in Princeton’s molecular biology department and was hired as an assistant professor.

In his academic life, Wang says his most notable accomplishments lie in two areas: brain evolution and synaptic plasticity, in which he has studied the synapses of the cerebellum, the part of the brain that helps you play tennis or dance or do anything that requires coordination. His lab, he explains, has shown that the cerebellum follows rules that are largely distinct and rarely found elsewhere in the brain.

In brain evolution, Wang says, his Princeton lab has found that the shared hallmark of smart birds and mammals is a big forebrain.

“Others work on this, too, but our special insight is that the internal proportions are a key factor,” Wang says. “Parrots, chimps, humans, and crows all have disproportionately big forebrains, more than the minimum needed to communicate with the rest of the brain. This extra brain mass supports complex behavior.”

The research has led Wang to conduct a study in which he and his students are ranking the smartest breeds of dogs. (The Portuguese water dog — like the one owned by President Barack Obama — ranks as No. 1 in their preliminary results. Wang’s dog, Willy, is a pug, a breed that he said ranks low in trainability but high in other factors.)

“Why are pugs attention-seeking? Why are poodles smart? Why do terriers chase everything in sight?” Wang asks. “Nobody has done a good job of connecting these with brain structure. Using veterinary scans, my undergraduates hope to make that connection.”

Canine intelligence has not been Wang’s only nontraditional research topic. By 2008, Wang was earning a national reputation among mainstream audiences for his research into presidential election polling data. For the race between Barack Obama and John McCain, Wang’s presidential poll­ing website, the Princeton Election Consortium, attracted more than 1.3 million visitors, he says. Wang prided himself on looking at several strands of polling data, and chafed at how mainstream news organizations selectively highlighted one data point at a time. 

Despite the potential for fame in political analysis, Wang — who describes himself as a “big, fat Democrat” — is ambivalent about resuming that endeavor for the 2012 election. “It’s become something that’s so mainstream,” he says. “Is it really necessary for me to do this now?”

Wang met his co-author, Aamodt, on election night in 2000 at a party in New Orleans where participants at the Society for Neuroscience were meeting. (If that sounds like a nerdfest, Wang says, he hired a brass band for the event and the party spilled out into the streets.)

Aamodt, at the time the editor of the Nature Neuroscience journal, remembers the meeting well. “One of our mutual friends dragged Sam over to me that night, and said something like, ‘You guys are talking about writing the same book, and instead of competing, you should write together,’” she says. “What were the odds?”

It took a while for them to get free time from their day jobs and research and write Welcome to Your Brain, which they completed in the spring of 2007. Wang came up with the idea for a sequel on how children’s brains work, and Bloomsbury USA bought the book on the title alone, Aamodt said.

They set to work on the new book in the fall of 2009. They read hundreds of neuroscience and psychology papers, plucking out the most interesting stuff and translating it for general readers. To ensure accuracy and a tone palatable for sensitive parents, they gave drafts to several of Vita’s preschool teachers and her pediatrician. They sought suggestions. Wang and Aamodt originally had included an anecdote about a friend of theirs — a neuroscientist — who was pregnant and having a beer. Someone yelled at the pregnant friend for drinking, and, Aamodt says, the expectant mother retorted something like: “The benefit of stress reduction from this one beer greatly outweighed any risk of having a beer.” 

“A number of doctors who read the draft — and I am not sure I agree with it — took the conservative view that it was irresponsible to encourage people to drink while someone was pregnant. I have a little more faith in women myself,” Aamodt says. “We were both like, ‘Ugh. It’s not that critically important. I guess we have to take it out.’ ”

In addition to their takes on breastfeeding and IQ, Welcome to Your Child’s Brain contains other surprising information, such as: A young person’s brain isn’t finished developing until his or her 20s; 20 percent of babies born between 34 and 37 weeks of gestation end up with “clinically significant behavioral problems,” and the risk of attention-deficit hyperactivity disorder is 80 percent higher than in full-term babies; children who hear more words while talking with their parents before age 2 learn language faster than children who hear fewer words; 3-year-olds take gender roles “as seriously as drag queens”; telling lies is an accomplishment for children because it shows that kids know what reality is and isn’t; and finally, Wang’s big bugaboo — that baby videos can be harmful to tots 2 and younger, and those who spend more time in front of a television screen, even if it’s Baby Einstein, know fewer words compared to kids who don’t watch television. 

“Television, in general, is inadvisable for any child under the age of 2,” Wang says. Then, his shoulders slump, and he seems to realize he sounds a bit alarmist. “If you’re a busy parent, and you need 15 minutes of quiet, maybe it’s OK to park your kid in front of the TV,” he says. 

Neuroscientist David Linden, author of The Compass of Pleasure (Viking, 2011), says Wang and Aamodt have managed to distinguish themselves in the crowded marketplace of brain books. “Sam and Sandra said, ‘We’re going to go slightly easier and slightly less technical and capture a wider slice and readership,’ which is just as valid,” says Linden, a professor at Johns Hopkins University.

Over lunch outside Prospect House, Wang’s 4-year-old acts like most others you see at restaurants. (Wang says Vita is careful to point out that she is 4-and-a-quarter years old.) One moment, Vita is spilling her drink; the next, she is rejecting foods she doesn’t want; and soon she is groping for her dad’s iPhone so she can play a game.

And Wang is like other dads, too. He entices her to eat all of her ham sandwich by offering her the reward of delicious, sugary fruit juice. 

But at other times, it’s clear Wang is equipped with parenting knowledge that might be more thoughtful than the average father’s. Wang and his wife, Rebecca, a physician at the Cancer Institute of New Jersey, plan to start teaching Vita a foreign language before she gets much older and it becomes harder for her brain to become fluent. Bilingual children, according to his new book, outperform monolingual children on tests that measure the ability to understand what people are thinking or feeling, or to predict another person’s point of view.

Indeed, one of Wang’s biggest priorities is teaching his daughter empathy. 

“Vita, if I take your sandwich, how does that make you feel?”

Vita makes her face look sad.

Wang explains: “We experience emotions in ourselves and we analyze emotions of others using the same brain structures,” he says. “If I can get her to make a sad face, then she’ll feel that sad feeling more directly, more than if I simply said, ‘Imagine how that would make you feel.’”

But some things are out of Wang’s control. 

When Vita is asked if she ever watches television, Wang interjects and says the family doesn’t own a television set, and only watches videos or movies on a DVD player. 

“When we watch TV, we watch it together,” he says.

Then he gets curious. “Vita, when you go to a friend’s house, what do you do?”

Vita responds: “Play. Only when I go to Miles’ home do I watch TV.”

Wang’s mouth drops. He is not amused, but is curious to hear more. Go on, he says. “What do you watch?”

Vita starts cracking up: “We watch Tom the Train. We always watch Tom the Train. He’s so funny. He goes through the tunnel and he falls over,” she says.

Wang smiles, and leans back with satisfaction. 

“My goodness,” the professor says, watching his latest finding emerge. 

Ian Shapira ’00 is a reporter at The Washington Post.