Mike came out to the yard, his wineglass in one hand and a piece of cheese in another. His wife, Perla Ni, a lawyer who directs a nonprofit, was working late. Where Mike has a loud, large and boisterous presence (a neighbor once compared him to a Labrador retriever, happily trampling everyone's shrubbery), Perla is quiet, petite, deliberate and self-contained. The only child of Chinese immigrants, she wants her sons to have considerably more fun than she had.

"Uh, can you keep an eye on them?" I asked Mike, reluctantly gathering my stuff to leave. "The society of 5-year-olds is fragile and may fall into savagery!"

"Yeah, yeah," he replied affably. "I'm a believer in that Rousseau theory — what's it called?"

"Something about a Noble Savage?" I said. "I'm more a believer in the truth of 'Lord of the Flies.' " My smile was thin and conveyed, For the love of God, can you please put your drink down and watch the kids?

His smile told me he wanted me to leave already.

In 2006, when their oldest son, Marco, was 2, Mike and Perla began what proved to be a two-year house search in Menlo Park and neighboring Palo Alto. They were yearning for the kind of classic neighborhood that Mike recalled from his childhood on the East Coast in Scott Township, a suburb of Pittsburgh. They were living in San Francisco, but they wanted to move out of the city to a playborhood — a version of American kid life featured in shows like "The Little Rascals" and "Leave It to Beaver," in which kids build forts and ride bikes outside, unsupervised — free, skirting danger, but ultimately always lucky. (The oddness of needing a neologism for what so recently would simply have been considered a "neighborhood" only reinforces his point.) Mike drove around deserted street after street: The kids were off at Lego robotics classes, Kumon learning centers or diving practice or squirreled away with their screens.

Despite having achieved a higher socioeconomic status for his family than he had as a kid, Mike felt his sons were at risk of having a worse childhood. Growing up in a middle-class Italian-American family in the 1960s and '70s, Mike rated school as boring-to-O.K., whereas after-school play time with the gang was awesome.

Like many places, Silicon Valley is sports-crazy, with kids participating in year-round travel clubs and working with private coaches. But Mike feels that organized team sports fail to teach the critical life skills that he and his friends learned in pickup games they had to referee themselves. They were forced to resolve their own disputes, because if they didn't, the game would end. Their focus was not on winning and losing, as when adults are in charge, he says, but simply on keeping the game going.

Mike recalls how his gang was often short of a quorum for games. There were two other boys their age, but one was deaf and the other, he says, was "whatever the P.C. way to describe what used to be called 'mentally retarded.' " Since they didn't want to "stoop all the way to girls," he says, giving me a smile, they found ways to change the rules to accommodate the two boys with special needs in their game — "not because a grown-up forced" them to be inclusive, Mike says, but because they were motivated to be.

Then, when Mike was in seventh grade, his family moved to a better house in an upscale development nearby, and the fun ended. Though the new house wasn't far from the old one — all Mike would have had to do was walk up the hill to play with his old friends — he instead spent his afternoons watching TV, drinking Coke and munching on saltines. He didn't blame his parents; it was bad luck — an unpredictable anomaly — that the new development wasn't a playborhood. But today it would simply be the norm. Playborhoods have all but disappeared.

"Everyone complains about kids not having enough free time, and being addicted to technology," Mike says. "There are a million studies documenting the negative effects of lack of free play in children. Well, we know the harms. I asked myself: What am I going to do about it for my kids?"

He analyzed the problem like an entrepreneur, by thinking of children as consumers and seeing their time as a scarce resource. Playing outside has to compete with screen time. (A typical 2-to-10-year-old child spends at least a couple of hours a day on screens; tweens spend more than four.) Parents who limit screen time, as local families often do, tend to compensate by piling on extracurricular activities and tutors.

Even if a boy wanted to play outside, Mike explains, with whom would he play? At any given hour, there might be a 30 percent chance that some kid was playing outside. But the so-called network effect, in which children influence one another's behavior, means that 30 percent might as well be zero, because it is low enough that no boy can count on it and so will default to his screen — causing the percentage to drop lower. That is, kids don't play outside because other kids don't play outside. Playing outside becomes like Betamax — it's just obsolete. But in the case of a playborhood, the vicious circle transforms into a virtuous one: When there's always another kid to play with, most kids want to play.

As part of Mike's quest for a playborhood, he began doing research and visiting neighborhoods in different parts of the country that he thought might fit his vision. The first place he visited was N Street in Davis, Calif., a cluster of around 20 houses that share land and hold regular dinners together. Children wander around freely, crossing backyards and playing in the collective spaces: Ping-Pong table, pizza oven and community garden. Mike told me the story of Lucy, a toddler adopted from China by a single mom who lived on N Street. When Lucy was 3, her mother died of cancer. But before she died, her mother gave every house a refrigerator magnet with a picture of Lucy on it. While the founders of N Street formally adopted Lucy, the entire community supported her. Mike pointed out that the childhood Lucy was having on N Street may be akin to one she might have enjoyed in a village in rural China, but it was extraordinary in suburban America. Lucy could wander around fearlessly, knowing she had 19 other houses where she could walk right in and expect a snack.

Mike spent some time in the Lyman Place neighborhood in the Bronx, where grandmothers and other residents organized to watch the streets — so dangerous that children were afraid to play outside — and block them off in the summer to create a neighborhood camp, staffed by local teenagers and volunteers. Mike also found his way to Share-It Square in Southeast Portland, Ore., a random intersection that became a community when a local architect mobilized neighbors to convert a condemned house on one corner into a "Kids' Klubhouse": a funky open-air structure that features a couch, a message board, a book-exchange box, a solar-powered tea station and toys.

Mike was aware of limits to the analogies. Those playborhoods were in lower- and middle-class communities; he and Perla had settled on a house in the Allied Arts area of Menlo Park, where the median home price is $2 million. (And the houses in neighboring North Palo Alto and Atherton cost even more.) Mike found himself up against the fact that in America, the ethos of wealth and the ethos of community are often in conflict: Part of what the wealthy feel they are buying is privacy and the ability to be choosy about whom they socialize with. Mike was determined that his kids would not only know their neighbors but would also see them, every day.

In order to achieve this, Mike decided he had to corral his neighbors to sign on to his platform. He designed big neon-yellow plastic signs like those used to warn of wet floors, emblazoned with an icon of children playing and the word Playborhood. He invited kids to parties and gave the signs to their parents, to put in their yards and on the road in front of their houses so their children could "reclaim the streets from cars." (We had the sign in our driveway, but my husband accidentally ran over it, and the shards of yellow plastic remained there for months — a good reminder, he said, of what happens to children who play in the street.)

Mike Lanza and his sons on the roof of their home, as seen from the backyard playhouse.

Mike also made another simple-but-radical move: In a neighborhood in which front yards are for admiration only, Mike installed a picnic table, close to the sidewalk, where he and his family often sat, so that people walking by would have to talk to them. Mike put a white board on the fence and started projecting videos and slide shows onto it, in hope of luring neighborhood children. And it worked: Dogs stop to drink at a fountain made from a large, flat millstone in the shape of a hockey puck, children wander over to the play river and people pause to read the quotes on the mosaics he had an artist design. One is from the children's book "The Big Orange Splot": "Our street is us and we are it. Our street is where we like to be, and it looks like all our dreams."

Mike has influenced our family as well. My kids and I made friends on our block by playing a game from Camp Yale in which we asked neighbors to contribute one ingredient to what turned out to be an apple-pear-blueberry-strawberry cobbler; when it was baked, we brought each​ ​​of them a piece. My daughter liked the game so much, she recently asked to make her birthday cake that way. Then, when our next-door neighbors generously passed along their trampoline, I spread the word that other children were welcome to play in our yard anytime. Sometimes visitors will be surprised when my children aren't home and they hear shrieks of laughter coming from our yard, as neighborhood kids bounce and squirt water guns they filled in our fountain, and I feel grateful to Mike for his vision.

Mike always talks about just wanting his boys to have a normal childhood, while complaining that his idea of normal is no longer normal. His free-time-is-for-goofing-around ethos is particularly anomalous in Silicon Valley. With all due respect to Westchester, Silicon Valley may have the densest concentration in the country of former engineers, executives and other highly educated women who have renounced work in favor of what they call uber-parenting — and they want results. Just as Silicon Valley leads the way in smartphones, Silicon Valley parents think they should be producing model kids, optimized kids, kids with extra capacity and cool features: kids who have start-ups (or at least work at one); do environmental work in the Galápagos; speak multiple languages; demonstrate a repeatable golf swing; or sing arias. To a comical extent, parents here justify the perverted ambition through appeals to research (enlarging the language center of the brain and so forth) while ignoring research on the negative effects on children of being micromanaged.

"What strikes me is that there is this extraordinary level of anxiety," Mike told me. "Parents don't have fundamental faith in their offspring." He dislikes the vast expansion of the role of parenting into every aspect of children's lives, including curating their children's hobbies with excruciating care, and he says he aspires to be "the opposite of a tiger parent." "As a libertarian, one of the biggest problems we have in American society is that children don't have enough freedom" — children thrive on benign neglect. "Look, there is always a power struggle between children and adults," he says. "One way to see the present is that the children have been decimated. It's not good for children that adults have so much control over them."

Local parents often talk about the rash of suicides among Palo Alto high school students in recent years. "It's been pretty clear to me since I moved here eight years ago that kids are just not happy here," Mike says, and "the suicides are just the extreme examples of the broader problem." He believes "the poor quality of children's lives around here" stems from their lack of autonomy. Basic developmental psychology posits that if children develop a fundamental sense that they (not their parents) are masters of their own destiny, they will be successful adults, and that without that belief they will flounder: It's easy to want to rid yourself of a life that doesn't feel truly your own.

Research suggests that students with controlling "helicopter" parents are less flexible and more vulnerable, anxious and self-conscious, as well as more likely to be medicated for anxiety or depression. Similarly, children whose time is highly structured — crammed with lessons and adult-supervised activities — may have more difficulty developing their own "executive function" capabilities, the ability to devise their own plans and carry them out. Conversely, the more time children spend in free play, the better they develop these capabilities.

Mike says he often feels alienated when he's talking to other parents. The common currency of conversation — rather than sports, politics or weather — is the achievements of your children. "I have exactly nothing to say in these conversations," Mike says. "Am I going to brag my kids are jumping on their trampoline, or went to the store by themselves? Parents don't measure themselves according to their kids' independence, as they used to, but according to accomplishments. To me, that's part of how I judge myself."

Reactions to Mike in the neighborhood are mixed. When the Lanzas first moved in, Mike had the idea that the neighbors on both sides should take down the fences between their yards to facilitate play. But unlike on N Street, none of them agreed. Mike complained to me that a neighbor asked Marco to stop climbing into her yard to see her son, even though her son wanted to see Marco. Many neighbors disapprove of boys playing pickup games in the streets and of the younger kids biking alone. Leo was allowed to ride around the neighborhood on his own when he was 5, and two years ago, when Nico was in first grade, he was allowed to bike a mile and a half to school alone.

Mike believes his children have grown by taking risks. "Marco is naturally physically cautious, and now he is working on a back flip onto the trampoline," Mike tells me. "I'm proud of that. He's worked his way up. Other kids learn to take risks at our house."

In the spring of last year, Mike installed 10-foot ladders in each of his sons' bedrooms so they could climb through a hole in their ceilings into the finished attic. Perla was not enthusiastic. ("She's not into the man-cave stuff," Mike says.) She was worried they would fall. And indeed, once, when Leo was playing in the attic, he tumbled down the hatch and hit his head. "To me, it was a bump on the head, which is a normal part of being a kid," Mike said. But Perla saw it as a head injury and took him to the hospital for a scan. "He was fine," Mike said, rolling his eyes.

Mike tells me that people sometimes ask him if he is afraid of lawsuits in the event of an injury on his property. He would never let fear of being sued dictate how he lives his life, he says.

What about second-degree manslaughter, I asked: an accident enabled by negligence, if, say, another child — or even one of his own — broke his neck leaping from the playhouse onto the trampoline. (Unenclosed trampolines are a staple of personal-injury law; an estimated 85,000 children under 14 were hurt on trampolines last year.) Does he ever worry about that?

He flashed me a look, then snorted with laughter.

One day last February, Peter Gray, a professor of psychology at Boston College and a fan of Mike's ideas, spent a day observing the Lanza boys at play. Gray says that when he gives talks on the critical importance of free play in normal development, audience members point out that they are sold on the idea, but that all the kids are on their screens. He always tells them about Mike's playborhood to show how parents can change their local culture.

As part of Gray's research, he accompanied Mike to meet the kids at school. Mike biked home with the younger kids while Gray and I biked after Marco and a friend as they rode their skateboards to the park. They amused themselves en route by doing tricks on strangers' stoops. At the park, they wobbled down steep cement curves with older and more skilled skaters as dusk set in.

"All mammals engage in dangerous play," Gray told me. "Dangerous play is how kids learn how to titrate fear. Not everyone has to learn quadratic equations" — which, he points out, most people forget the minute they leave school anyway — "but at some point in our lives, we will all be in stressful situations and we need to be able to keep our cool. Sometimes there are accidents," he added, "kid goats fall off cliffs while playing, or whatever, but they're rare. If the instinct wasn't of evolutionary benefit, the behavior would have been rooted out."

"Well, mother goats don't die of heartbreak the way we do," I said peevishly.

He conceded that among humans, mothers in many societies have a tendency to worry. "But there were no helicopter hunter-and-gatherer moms!" he said pointedly. "Kids were with their moms until they were 4, and then they were on their own with the other kids, practicing through play the intricate skills they need to survive: finding their way through the jungle, making weapons and identifying food sources."

Continue reading the main story