How Preschool Can Make You Smarter and Healthier
Just two years of preschool can stay with a person for decades, making them healthier, more intelligent adults.

There was a sense of idealism in the air in 1971 when Craig Ramey, a psychologist in his late 20s with a newly minted Ph.D., took a job in Chapel Hill, North Carolina, to launch what would become one of the longest-running educational experiments in history. He became a lead researcher at the University of North Carolina’s Frank Porter Graham Child Development Center, named for a former U.S. Senator, university president, and famous advocate for civil rights and the working poor. He and Joseph Sparling, the center’s senior investigator and associate director and a former school principal, wanted to study a sample of Chapel Hill children and test whether it was possible to change the course of a life by stepping in early, from infancy. They named their experiment the Abecedarian Project, from an obscure Latinate word for an alphabetical sequence.

The University of North Carolina had been a hotbed of civil rights activism and liberal social ideas throughout the 1960s, but Chapel Hill had only desegregated its last high school in 1966. The racial and economic divide had left an imprint on the education system—children from the poorest households, many of them African-American, struggled with the most basic lessons in school. Conventional wisdom said you were either born smart or you weren’t (a misconception that lingers in the public’s imagination even today). But in the 1960s, evidence mounted from a few small parenting and education projects for young children—combined with laboratory tests on rats, cats and monkeys—that the first years of life could shape your intelligence.
“In the 1960s, there was talk about the ‘cycle of poverty’ and how generation after generation had problems in school and life,” Sparling recalled, more than three decades later, in a report from the center, now called the FPG Child Development Institute. “There was an optimistic feeling at the time that we could solve this social problem.”
It was a seminal moment—the first chapter in whole line of research that is still changing how we think about intelligence, poverty, and the child brain. Since the 1990s, enthusiasm over the science behind early childhood has mobilized an enormous and motley group of interests to support investment in preschool—from Georgia conservatives to film star and director Rob Reiner to President Obama. But in the 1960s and 1970s, this research was brand new. No one had seen the intimate workings of a live human brain—the MRI scan wouldn’t be tested on humans until 1977. Yet scientists believed early childhood was a crucial time for learning, and they started a handful of small preschool experiments with children from poor families all over the country. In Ypsilanti, Michigan, one of the most enduring of these studies, the Perry Preschool Project, tested roughly 120 children, ages three and four, half of whom received two years of preschool between 1962 and 1967.
“There was an optimistic feeling at the time that we could solve this social problem.”
Ramey and Sparling wanted to start earlier in children’s lives, with babies. Sparling, who took the lead on writing the curriculum used in the study, borrowed ideas from Freidrich Fröbel, who invented kindergarten in 19 th -century Germany. But he and Ramey used modern experimental design, including a controlled, randomized sample, to test the learning games that they wrote over the five years of the program.
They hired more than a dozen child care workers and teachers and recruited mothers who were about to give birth. The families had to score high on a range of risk factors, such as whether the parents were high-school dropouts, had a four-figure annual household income (which was low, even in those days), or relied on unstable or unskilled jobs. These were among the markers of poverty in Chapel Hill. Between 1972 and 1977, the researchers enrolled 111 babies in the experiment when they were less than 12 weeks old. Fifty-four of them were offered diapers and 15 months worth of infant formula and sent home.
The other 57 received the Abecedarian curriculum. Five days a week, ten hours each day, 50 weeks per year for five years, a group of trained child-care professionals and teachers taught, played with, cuddled, diapered, and fed them. “What in the world are you going to teach a baby that little? You’re going to talk to it. Talk, talk, talk,” says Frances Campbell, a clinical psychologist hired to evaluate the children’s progress. Infants and toddlers learn about language, social interaction, and emotion by gazing into the faces of adults and exchanging gestures and expressions back and forth, a process researchers now call “serve and return.” In the beginning, the curriculum included peekaboo, learning the meaning of new words, or playing with an adult in front of a mirror.

Campbell told Ramey openly that she was skeptical that the program would make any difference. “I believe in genetics”—nature over nurture—she recalled telling him in an interview 40 years later with the University of North Carolina’s campus magazine. But even in infancy, the kids in child care were more responsive than the ones in the control group. By age three, the group enrolled in the Abecedarian preschool had an 18-point higher average IQ score.
Campbell kept tracking the children through school. At age eight, the kids in the preschool group were less likely to have failed a grade in school than the control group. At ages 12 and 15, they had better reading, math, and writing scores. By 21, they were more likely to attend college and less likely to be teenage parents, marijuana users, or cigarette smokers.
Last year, Campbell, who is now in her early 80s, co-published a follow-up study on Abecedarian in the journal Science with a group of researchers, including Nobel Prize-winning economist James Heckman, one of the country’s leading advocates for preschool education. This time they examined not external measures of success, risk, or failure, but the health of the Abecedarian alumni. More than four decades after the project started, the graduates of the preschool group were still healthier. They had lower blood pressure than the control group. Moreover, several of the men from the control group suffered from metabolic syndrome—a combination of obesity, high cholesterol, and hypertension that put them at risk for heart attack and stroke—but none of men from the preschool program did.
“This tells us that adversity matters and it does affect adult health,” Heckman told the New York Times when the study was released. “But it also shows us that we can do something about it, that poverty is not just a hopeless condition.”
The long-lasting results also dispel a common notion that kids bounce back easily from troubles in early childhood—that it’s a “developmental delay [and] they’ll just catch up,” says Pat Levitt, a neuroscientist at the University of Southern California. “Unless you do the long-term studies, how are you going to argue with that?”
Signs of Stress
Though we’re now better at explaining how the young mind develops, the findings of Abecedarian and the Perry Preschool Project—which followed its preschoolers into their 40s and found that they earned more and relied less on government assistance—have never gotten stale. Even a number of recent White House reports mention both Abecedarian and Perry.
The results of Abecedarian have been so enduring that the study has become a kind of cause célèbre. How you interpret the Abecedarian experience is directly related to what you think about the role of parents versus government in shaping children’s behavior. Universal preschool advocate Timothy Bartik believes Abecedarian’s curriculum is powerful enough and similar enough to programs offered today (one example, Educare, is run in several states with money from big foundations) that it should be offered to all disadvantaged kids across the United States.
But there are also naysayers. Grover “Russ” Whitehurst, a Brookings Institution senior fellow and former education policy advisor to Mitt Romney’s presidential campaign, calls Abecedarian a “very small hothouse program” that one should view “with a great deal of caution.” Whitehurst is dubious about universal preschool and thinks early education funding should be targeted only to the poorest families who need it most.
Still, among experts, including those most cynical about government-funded education, almost no one argues today that intelligence can’t change or that early life experiences don’t matter. The legacy of Abecedarian, the evidence gathered over 40 years, has become undeniable—so undeniable that New York University child psychologist Clancy Blair now calls it a theory, a well-honed framework about how the stress of poverty batters child brains.
Blair was a graduate student of Craig Ramey’s in the 1990s. By then, Ramey had moved to the University of Alabama, Birmingham, and was poring over the results of a larger set of field trials of the Abecedarian method, called the Infant Health and Development Program, run from 1985 to 1988 with nearly 1,000 babies in eight locations, including Miami, Dallas, Seattle, and the Bronx. Many of the families involved were poor, and 40% of the mothers hadn’t finished high school. In addition, all of the babies in this study were born underweight—less than five and a half pounds—putting them at higher risk for cognitive problems later in life.
The early results looked promising. Although the Abecedarian-style curriculum didn’t seem to provide as much help to the children who were smallest at birth, it did give a boost to the children whose birth-weights were more than four and a half pounds. From the latter group, the kids who were offered preschool scored higher on IQ tests at ages five and eight.
As he worked with Ramey to analyze the study results, Blair began to wonder, “What was going on? What is it about these programs that’s the active ingredient?” Though he was a psychologist by training, he started digging into new research in neuroscience.

The 1990s were an explosive time for brain science. In 1997, when Hillary Clinton held a conference at the White House on early childhood development, there was a flurry of media coverage about impressionable young brains. At the conference, a neuroscientist reportedly described a famous experiment which showed that cats would go blind when their eyes are deprived of light as kittens, demonstrating that the brain needs certain kinds of stimulus early to develop properly. Around the same time, a few parenting fads—including Baby Einstein, a line of videos and toys whose effectiveness has since been called into question by experts—claimed to offer some kind of alchemy that could make children smarter at a young age.
Mass-marketing may have distorted the basic brain science, but experts agreed that the research needed to become more precise to be useful. Blair and other scientists wanted to pinpoint what might be happening in the brains of the poor children that Abecedarian and other similar programs were trying to reach. In 2002, Blair published a paper that suggested that emotion and stress in young children might interfere with developing parts of the brain that regulate decision-making skills that are important to success in school—and later to holding down a job and managing an adult life. These abilities are referred to as “self-regulation” and are controlled by part of the brain called the prefrontal cortex, which develops rapidly in infant and toddler years.
“The effects of Perry and Abecedarian were through self-regulation—the ability to regulate stress.”
Around the same time, Blair started taking saliva samples from four-year-olds in central Pennsylvania who were enrolled in the federally-funded Head Start program. Then he gave them a test of cognitive skills: a simple task that asked children to tap wooden pegs. The children who had sustained high levels of cortisol, a stress hormone, did worse on the peg test. He followed the kids into kindergarten, where he found higher cortisol connected to poorer math abilities.
He and his research team started tracking more than 1,200 children in Appalachia and the Deep South. They kept taking saliva samples, this time correlating them to parenting styles in a paper they ultimately published in 2008. Children from families whose parenting styles looked a bit like Abecedarian—involving play and exploration—had lower levels of cortisol. But the more impoverished the family, the less likely they were to be able to produce this kind of parenting.

Blair’s work lines up with volumes of other studies produced over the last decade—head scans of neglected orphans in Romania and of Texas teenagers with histories of mistreatment early in life show disruptions in brain functions. Still other studies demonstrate that low-income children and children of mothers who have suffered from depression have higher levels of stress hormones. Models of brain development from research on both rats and children suggest that too much stress early in life can forever make the brain overly reactive to threats and crisis. Stress in childhood begets a lifetime of stress.
Blair was unsurprised when he heard the results of the most recent study on Abecedarian children. Why do the adults who never experienced Abecedarian’s preschool curriculum have high blood pressure? “That’s stress,” he says. “Stress is bad for health…The effects of Perry and Abecedarian were through self-regulation—the ability to regulate stress.” The children in the control group went back home, where they had little help from adults to counterbalance the difficulty of living in poverty-stricken households.
Around the World
Joseph Sparling, now 79 years old, is surprised by where Abecedarian has led his career. “To think that you might have gotten an idea back in the 1970s that turns out to have real usefulness in 2015,” Sparling says. “That’s very gratifying and very humbling.” He has been traveling the world promoting the Abecedarian curriculum in places as far afield as Romania, Winnipeg, Manitoba, and Australia. Recently, the Australian government has sent him to some of the remotest parts of the Northern Territory, reachable only by small plane or rugged back roads, to teach Abecedarian methods in tiny Aboriginal communities. In early March, he flew to Brisbane to train nearly three dozen state employees including seven educators who are promoting Abecedarian across Queensland.
He has had a lot of conversations with neuroscientists in the last few years, but hasn’t changed his methods much over the years. The science seems to suggest that Sparling and Ramey got it right the first time. “We made some lucky but well-informed choices,” he says. “So far nobody has come up with a more proven approach.”
Photo credits: Shanna Trim/Flickr (CC BY) , University of North Carolina/NIH