New evidence on brain development during a child's early years makes it clear that early childhood should be a focus of increased policy attention. We now know that the basic architecture of the brain is constructed through an ongoing process that might be compared to the construction of a home: Beginning before birth, the brain's foundation is laid, with the neurological equivalent of the framing of rooms and the installation of the electrical and plumbing systems occurring in a predictable sequence that continues through early adulthood.
The brain's architecture is built over a succession of "sensitive periods," each of which involves the formation of specific circuits associated with particular abilities. Once a circuit is operational, it provides a foundation for the construction of later-developing circuits. A strong foundation in a child's early years helps promote lifelong achievement and positive behavior, while a weak foundation increases the chances of later problems. Nobel-laureate economist James Heckman describes this as "learning begets learning" -- early mastery of a range of cognitive and social competencies improves the ability of children to learn at later ages. Early interventions have the potential to improve life chances.
The early years also appear to be a sensitive period for the development of socio-emotional behaviors such as a child's ability to pay attention and to control emotions. These, too, have connections to the brain, as early emotional experiences become literally embedded in the architecture of infants' brains. Self-regulation can help make children eager learners in school, and may also encourage parents to engage them in learning activities in the home.
The quality of early-learning environments differs profoundly for rich and poor children. For example, kindergarteners at the top of the socioeconomic distribution are four times as likely as those at the bottom to have a computer in their home. They typically have three times as many books, are read to more often, watch far less television, and are more likely to visit museums or libraries. One study found that 3-year-olds in low-income families had half the vocabulary of their more affluent peers, which in turn could be explained by the lower quality and quantity of parental speech.
Differences in learning environments contribute to large gaps in test scores, even among preschoolers. Numerous studies have compared the outcomes of preschool children from different socioeconomic backgrounds and racial or ethnic groups; what they've found are large differences in language and cognitive skills, not just at school entry but at age 3, and perhaps even as early as 1 year of age.
The Promise of Early Education
Rigorous evaluations of very intensive early-childhood programs prove that such programs can produce lasting improvements in the life chances of poor children. Recent research also suggests that even less-expensive Head Start and prekindergarten programs can boost early achievement significantly. (Head Start has been shown to improve children's long-term outcomes as well.) In contrast, the impacts of more typical preschool or day-care settings on achievement and behavior are more modest. Thus, not all early-childhood-education programs produce similar effects.
The well-known Perry Preschool program has demonstrated that intensive programs can indeed improve the life chances of disadvantaged children. In the 1960s, Perry provided one or two years of part-day educational services and home visits to low-income, low-IQ African American children ages 3 and 4 in Ypsilanti, Michigan. Perry's impacts on kindergarten IQ scores at school entry were impressive. Although these IQ effects faded out by third grade, the program produced lasting effects through age 40 on key adult outcomes such as employment, earnings, and arrests. At age 40, one-quarter fewer Perry adults were poor than the adults in the comparison group. Viewed from an economic perspective, the investment in Perry yielded a 17 percent annualized rate of return, most of which accrued to taxpayers in the form of higher tax receipts and lower crime costs, and some of which benefited the recipients directly in higher earnings.
The even more intensive Abecedarian program -- which began in 1972 and served the children of low-income, mostly African American women from Chapel Hill, North Carolina -- produced somewhat different but equally striking long-term impacts. For example, children who participated in Abecedarian were much more likely to attend college and to work in high-skill, better-paid jobs, and much less likely than comparable children to become teen parents. Despite the program's $18,000 annual cost, the total economic value of Abecdarian's benefits far exceeded the program's costs.
PRE-K AND HEAD START ACHIEVEMENTS
Ideally, expensive programs like Perry and Abecedarian could be widely implemented, since their benefits substantially exceed their costs. But existing publicly funded early-childhood programs, though more modest, produce significant benefits as well. Several evaluations of state-initiated prekindergarten programs show impressive short-run impacts on children's academic skills. For example, a study of pre-K programs implemented in five states found that they improved vocabulary, print awareness, and math achievement. An evaluation of Tulsa, Oklahoma's pre-K program found even larger impacts. We do not yet know how long these will last, nor whether effects on behavior will rival those of the Perry and Abecedarian programs, but the initial results are promising.
Much more is known about the impacts of the Head Start program, which has a 40-year history. A recent experimental evaluation conducted for the Administration for Children and Families found positive short-term effects of program participation on pre-reading and -writing skills for 3- and 4-year olds, but not on advanced skills in these two outcome domains. Head Start participation also increased parent-reported literacy skills of children and improved the behavior of 3-year-olds.
How can we explain the somewhat larger short-run effects estimated for recent state prekindergarten programs compared with Head Start? A likely explanation is that pre-K programs hire teachers with higher levels of qualifications, pay them more, and offer a more academically oriented curriculum. For example, only about one-third of Head Start teachers have completed a bachelor's degree, whereas all of the recently evaluated pre-K programs had college-educated teachers.
For policy purposes, the crucial question is whether Head Start impacts persist over time, as this will indicate whether program benefits are likely to outweigh program costs. Studies of children who participated in Head Start several decades ago suggest lasting impacts on schooling attainment and perhaps criminal activity, while test-score impacts appear to fade out over time. Like those of Abecedarian and Perry, these impacts were large enough to generate benefits to society that outweigh the program costs.
Current Priorities and a Proposal The influence of the preschool years on children's later achievement and success is not well reflected in current government budget priorities, which allocate only one-seventh as much money per child for prekindergarten early-education and child-care subsidies for 3- to 5-year-olds as for K-12 schooling. Many social policies are devoted to playing catch-up to counteract children's early disadvantages, but disparities are already apparent among young children, and many disadvantaged children never catch up. There is now hard scientific evidence on the benefits of broad-based, proactive efforts to enroll children in and near poverty in high-quality early-education programs, beginning at age 3. These programs combine:
- teachers who are well-educated or have received extensive training in areas specific to the care and education of young children, and who receive salaries comparable to those of elementary-school teachers;
- a well-implemented curriculum, small class sizes, high adult-to-child ratios, with stimulating materials available in a safe physical setting;
- a language-rich environment; and
- caring, responsive interactions between staff and children.
One proposal would be to provide two years of intensive, half-day, high-quality early-childhood education to all low-income 3- and 4-year-old children in the United States. These classes would be led by a college-educated teacher and limited to six students per instructor. Teachers would devote the remaining half of their workday to parent-outreach efforts, intended to involve parents as partners in their children's learning and help them to access available support and social services. The annual per-child cost of the early-education component of this program might total as much as $8,000 per child, or $16,000 over the entire two-year enrollment period. Providing wraparound child care for working mothers would add $4,000 a year to this total. To preserve the gains from preschool education programs, it is important that public schools align their early-grade curricula with those of the preschool programs.
Although costly, the benefits deriving from a two-year pre-K program for low-income children would almost certainly exceed the costs of such a program, as earlier evaluations have shown. Indeed, it is likely that program benefits would exceed costs several times over, as they would provide a firm and vital foundation for later learning and positive behavior.