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 occuring 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. …