Flush.

Were he to update the book to reflect the experience of today’s children, he’d need to call it “All I Really Need to Know I Learned in Preschool,” as kindergarten has changed. The half day devoted to fair play and nice manners officially began its demise in 1983, when the National Commission on Excellence in Education published “A Nation at Risk,” warning that the country faced a “rising tide of mediocrity” unless we increased school achievement and expectations. No Child Left Behind, in 2002, exacerbated the trend, pushing phonics and pattern-recognition worksheets even further down the learning chain. As a result, many parents, legislatures and teachers find the current curriculum too challenging for many older 4- and young 5-year-olds, which makes sense, because it’s largely the same curriculum taught to first graders less than a generation ago. Andersen’s kindergartners are supposed to be able to not just read but also write two sentences by the time they graduate from her classroom. It’s no wonder that nationwide, teachers now report that 48 percent of incoming kindergartners have difficulty handling the demands of school.

Friedrich Froebel, the romantic motherless son who started the first kindergarten in Germany in 1840, would be horrified by what’s called kindergarten today. He conceived the early learning experience as a homage to Jean-Jacques Rousseau, who believed that “reading is the plague of childhood. . . . Books are good only for learning to babble about what one does not know.” Letters and numbers were officially banned from Froebel’s kindergartens; the teaching materials consisted of handmade blocks and games that he referred to as “gifts.” By the late 1800s, kindergarten had jumped to the United States, with Boston transcendentalists like Elizabeth Peabody popularizing the concept. Fairly quickly, letters and numbers appeared on the wooden blocks, yet Peabody cautioned that a “genuine” kindergarten is “a company of children under 7 years old, who do not learn to read, write and cipher” and a “false” kindergarten is one that accommodates parents who want their children studying academics instead of just playing.

That the social skills and exploration of one’s immediate world have been squeezed out of kindergarten is less the result of a pedagogical shift than of the accountability movement and the literal-minded reverse-engineering process it has brought to the schools. Curriculum planners no longer ask, What does a 5-year-old need? Instead they ask, If a student is to pass reading and math tests in third grade, what does that student need to be doing in the prior grades? Whether kindergarten students actually need to be older is a question of readiness, a concept that itself raises the question: Ready for what? The skill set required to succeed in Fulgham’s kindergarten — openness, creativity — is well matched to the capabilities of most 5-year-olds but also substantially different from what Andersen’s students need. In early 2000, the National Center for Education Statistics assessed 22,000 kindergartners individually and found, in general, that yes, the older children are better prepared to start an academic kindergarten than the younger ones. The older kids are four times as likely to be reading, and two to three times as likely to be able to decipher two-digit numerals. Twice as many older kids have the advanced fine motor skills necessary for writing. The older kids also have important noncognitive advantages, like being more persistent and more socially adept. Nonetheless, child advocacy groups say it’s the schools’ responsibility to be ready for the children, no matter their age, not the children’s to be prepared for the advanced curriculum. In a report on kindergarten, the National Association of Early Childhood Specialists in State Departments of Education wrote, “Most of the questionable entry and placement practices that have emerged in recent years have their genesis in concerns over children’s capacities to cope with the increasingly inappropriate curriculum in kindergarten.”

Furthermore, as Elizabeth Graue, a former kindergarten teacher who now studies school-readiness and redshirting at the University of Wisconsin, Madison, points out, “Readiness is a relative issue.” Studies of early-childhood teachers show they always complain about the youngest students, no matter their absolute age. ‘In Illinois it will be the March-April-May kids; in California, it will be October-November-December,” Graue says. “It’s really natural as a teacher to gravitate toward the kids who are easy to teach, especially when there’s academic pressure and the younger kids are rolling around the floor and sticking pencils in their ears.”

But perhaps those kids with the pencils in their ears — at least the less-affluent ones — don’t need “the gift of time” but rather to be brought into the schools. Forty-two years after Lyndon Johnson inaugurated Head Start, access to quality early education still highly correlates with class; and one serious side effect of pushing back the cutoffs is that while well-off kids with delayed enrollment will spend another year in preschool, probably doing what kindergartners did a generation ago, less-well-off children may, as the literacy specialist Katie Eller put it, spend “another year watching TV in the basement with Grandma.” What’s more, given the socioeconomics of redshirting — and the luxury involved in delaying for a year the free day care that is public school — the oldest child in any given class is more likely to be well off and the youngest child is more likely to be poor. “You almost have a double advantage coming to the well-off kids,” says Samuel J. Meisels, president of Erikson Institute, a graduate school in child development in Chicago. “From a public-policy point of view I find this very distressing.”

Nobody has exact numbers on what percentage of the children eligible for publicly financed preschool are actually enrolled — the individual programs are legion, and the eligibility requirements are complicated and varied — but the best guess from the National Institute for Early Education Research puts the proportion at only 25 percent. In California, for instance, 76 percent of publicly financed preschool programs have waiting lists, which include over 30,000 children. In Pennsylvania, 35 percent of children eligible for Head Start are not served. A few states do have universal preschool, and among Hillary Clinton’s first broad domestic policy proposals as a Democratic presidential candidate was to call for universal pre-kindergarten classes. But at the moment, free high-quality preschool for less-well-to-do children is spotty, and what exists often is aimed at extremely low-income parents, leaving out the children of the merely strapped working or lower-middle class. Nor, as a rule, do publicly financed programs take kids who are old enough to be eligible for kindergarten, meaning redshirting is not a realistic option for many.

One morning, when I was sitting in Elizabeth Levett Fortier’s kindergarten classroom in the Peabody School in San Francisco — among a group of students that included some children who had never been to preschool, some who were just learning English and some who were already reading — a father dropped by to discuss whether or not to enroll his fall-birthday daughter or give her one more year at her private preschool. Demographically speaking, any child with a father willing to call on a teacher to discuss if it’s best for that child to spend a third year at a $10,000-a-year preschool is going to be fine. Andersen told me, “I’ve had parents tell me that the preschool did not recommend sending their children on to kindergarten yet, but they had no choice,” as they couldn’t afford not to. In 49 out of 50 states, the average annual cost of day care for a 4-year-old in an urban area is more than the average annual public college tuition. A RAND Corporation position paper suggests policy makers may need to view “entrance-age policies and child-care polices as a package.”