Research on Head Start
The National Head Start Association summarizes and links to the key research on Head Start.
http://www.nhsa.org/research/research_re_bites.htm

Relationships Between Poverty and Psychopathology
An income intervention -- the opening of a casino -- that moved families out of poverty for reasons that cannot be ascribed to family characteristics reduced the incidence of conduct and oppositional defiant disorders among the once-poor children to levels comparable to never-poor children. Anxiety and depression symptoms were unaffected.
http://jama.ama-assn.org/cgi/content/abstract/290/15/2023

Family and Child Experiences Survey
FACES is a national longitudinal study of Head Start -- the cognitive, social, emotional, and physical development of Head Start children, the characteristics, well-being, and accomplishments of families, the observed quality of Head Start classrooms and the characteristics, needs, and opinions of Head Start teachers and other program staff.
http://www.acf.hhs.gov/programs/opre/hs/faces/index.html

High Scope Research
High Scope is best known for the Perry School Project, a longitudinal study begun in the 1960's on the impact of quality preschool experiences on the subsequent development of children into their adulthood. This research is available on the High Scope Web site.
http://www.highscope.org/Content.asp?ContentId=3

The Abecedarian Project
The Abecedarian Project was a carefully controlled study of low-income infants with similar initial infant motor and mental test scores, half of whom were randomly assigned to receive early intervention in a high quality child care setting. Children in the intervention group had significantly higher scores on mental tests than children in the control group at 18 months and into adulthood.
http://www.fpg.unc.edu/~abc/

The NICHD Study of Early Child Care and Youth Development
The NICHD Study of Early Child Care is the most comprehensive child care study conducted to date in the United States. Ongoing updates about the study and results are available at http://public.rti.org/secc

Selected Research Abstracts:

Analyses that adjusted for maternal vocabulary score, family income, child gender, observed quality of the home environment, and observed maternal cognitive stimulation indicated that the overall quality of child care, and language stimulation in particular, was consistently but modestly related to cognitive and language outcomes at ages 15, 24, and 36 months. http://secc.rti.org/abstracts.cfm?abstract=18

Quality of maternal caregiving was the strongest predictor of cognitive competence, as well as caregivers' ratings of social competence. The quality of non-maternal caregiving was associated with cognitive competence and caregivers' ratings of social competence. These findings provide empirical support for policies that improve state regulations for caregiver training and child-staff ratios. http://secc.rti.org/abstracts.cfm?abstract=25

Research on child care reveals significant associations between quality of care and children's developing skills and well-being. But are these associations causal? Three propositions received support, principally in the cognitive domain: (a) associations between quality and outcomes remained even with child and family factors controlled; (b) associations between care and outcomes were domain-specific; (c) outcomes were predicted by the quality of earlier care with concurrent care controlled. The fourth proposition, that associations between quality and outcomes would be significant when the child's earlier abilities were controlled, received limited support. There was no support for the fifth proposition, that quality and outcomes would exhibit dose-response relations. Thus, the argument that child-care quality affects child outcomes was only partially supported by this investigation.
http://secc.rti.org/abstracts.cfm?abstract=40

Investing in Our Children: What We Know and Don't Know About the Costs and Benefits of Early Childhood Interventions
This RAND review of the research finds that greater investments in early childhood would not only benefit children but also save the government money in the form of lower welfare payments, higher tax revenues, and lower criminal justice system costs.
http://www.rand.org/publications/MR/MR898/

Child Care Quality: Does It Matter and Does It Need to Be Improved?
This comprehensive analysis of the research for the U.S. Department of Health and Human Services reviews in detail the findings regarding the impact of quality child care.
http://aspe.hhs.gov/hsp/ccquality00/ccqual.htm

Sample Findings:

Children who attended centers that met more recommended quality guidelines had fewer behavior problems at 24 and 36 months, and higher school readiness and language comprehension scores at 36 months. There were significant linear trends between the number of recommended standards that were met and children's concurrent adjustment.
http://aspe.hhs.gov/hsp/ccquality00/ccqual.htm#outcomes

At 24 months, children displayed fewer behavior problems and more positive social behaviors when centers met the recommended child:adult ratio. At 36 months, children whose caregivers had specialized training or who had more formal education exhibited fewer behavior problems and obtained higher school readiness and language comprehension scores.
http://aspe.hhs.gov/hsp/ccquality00/ccqual.htm#outcomes

The quality of child care during the first 3 years was related to children's school readiness, expressive language, and receptive language at 3 years. Comparisons of children in high-quality and low-quality child care were significant for measures of school readiness, expressive language, and receptive language at 36 months.
http://aspe.hhs.gov/hsp/ccquality00/ccqual.htm#outcomes

From Neurons to Neighborhoods: The Science of Early Childhood Development This 2000 National Research Council report reviews the research on early development in detail, and offers recommendations for addressing the implications of the research that experiences early in childhood matter for children's cognitive, emotional, physical and social development.

Full Report:
http://www.nap.edu/books/0309069882/html/

Quotes:

The scientific evidence ranging from behavioral genetics and neuroscience to policy analysis and intervention research on the significant developmental impacts of early experiences, caregiving relationships, and environmental threats is incontrovertible. Virtually every aspect of early human development, from the brain's evolving circuitry to the child's capacity for empathy, is affected by the environments and experiences that are encountered in a cumulative fashion, beginning early in the prenatal period and extending throughout the early childhood years. The question today is not whether early experience matters, but rather how early experiences shape individual development and contribute to children's continued movement along positive pathways. P. 388
http://books.nap.edu/books/0309069882/html/388.html

The long-standing debate about the importance of nature versus nurture, considered as independent influences, is overly simplistic and scientifically obsolete. Scientists have shifted their focus to take account of the fact that genetic and environmental influences work together in dynamic ways over the course of development. Both genetically determined characteristics and those that are highly affected by experience are open to intervention. The most important questions now concern how environments influence the expression of genes and how genetic makeup, combined with children's previous experiences, affects their ongoing interactions with their environments during the early years and beyond. P. 388-389
http://books.nap.edu/books/0309069882/html/388.html

A great deal of attention is now being paid to research indicating that the amount of talk mothers direct to their children is strongly associated with the children's vocabulary growth (Hart and Risley, 1995; Huttenlocher et. Al., 1991), as well as with the children's performance on measures of emergent literacy and print-related skills (De Temple and Snow, 1992). P. 137
http://books.nap.edu/books/0309069882/html/137.html

Although differences in mother's talk are associated with their social class, it is critical to recognize that other characteristics that can be more easily targeted by early interventions are as strongly related to children's accomplishments as the advantages conferred by socioeconomic status. A composite of parental behaviors that included "just talking," "trying to be nice," "telling children about things," "giving children choices," and "listening" accounted for over 60 percent of the variance in the rate of children's vocabulary growth and vocabulary use and almost 60 percent of the variance in their IQ scores at age 3 (Hart and Risley, 1995). P. 137
http://books.nap.edu/books/0309069882/html/137.html

Evidence of the importance of verbal input during the years when verbal development is proceeding rapidly has also emerged from research on child care. Children whose teachers talk with them a lot (and many don't!) have higher scores on tests of both verbal and general ability. This is especially the case when the talking consists of the teacher encouraging, questioning, and guiding the children's exploration and learning. Positive inputs are positive inputs, whether they happen at home or in child care. P. 138
://books.nap.edu/books/0309069882/html/138.html#pagetop

Eager to Learn: Educating Our Preschoolers
This 2001 National Research Council report reviews the research on early childhood learning and program effectiveness. http://www.nap.edu/books/0309068363/html/

Selected Findings:

Development is dependent on and responsive to experience, allowing children to grow far more quickly in domains in which a rich experiential base and guided exposure to complex thinking are available than in those where they receive no such support. Environment—including cultural context—exerts a large influence on both cognitive and emotional development. Genetic endowment is far more responsive to experience than was once thought. Rapid growth of the brain in the early years provides an opportunity for the environment to influence the physiology of development. P. 306
http://books.nap.edu/books/0309068363/html/306.html

Data on Children and Poverty

The National Center on Children and Poverty says that the United States' child poverty rate is substantially higher--often two-to-three times higher--than that of most other major Western industrialized nations. While the child poverty rate has been reduced by more than one quarter since it peaked in 1993, the decline stalled in 2001.
http://www.nccp.org/publications/pub_762.html

Kids Count
The Annie E. Casey Foundation Kids Count project has state-by-state data on child poverty rates and other indicators of child well-being, as well as key reports on disadvantaged children in the U.S. http://www.aecf.org/kidscount/

Child Trends DataBank
Child Trends' interactive DataBank includes national trends and research on over 80 key indicators of child and youth well-being in an easily searchable format.
http://www.childtrendsdatabank.org

Sample Findings:

Three- to five-year old children living in poverty are much less likely to have the three or four cognitive/linguistic school readiness skills than are children living above the poverty threshold. Young children growing up in poverty are more likely to have lower cognitive abilities and school achievement and impaired health and development. The problems associated with being raised in severe poverty (less than 50 percent of the poverty threshold) are correspondingly worse.
http://www.childtrendsdatabank.org/indicators/7EarlySchoolReadiness.cfm

Black children are far more likely than other children to experience long-term poverty. A third of black children ages 0-5 in 1987 experienced at least six of the next 10 years in poverty, compared with less than five percent of other children.
http://www.childtrendsdatabank.org/indicators/61LongTermPoverty.cfm