Programs that Work
The Abecedarian Project
Healthy and Safe Children
Children Ready for School
Children Succeeding in School
Youths not using alcohol, tobacco, or illegal drugs
Students performing at grade level or meeting state curriculum standards
Children ages 0 to 5 exhibiting age-appropriate mental and physical development
Children experiencing good physical health
Age of Child
Early Childhood (0-8)
Type of Setting
Child Care / Preschool
Type of Service
Health Care Services
Type of Outcome Addressed
Cognitive Development / School Performance
Substance Use and Dependence
Evidence Level (What does this mean?)
The Abecedarian Project was a comprehensive early education program for young children at risk for developmental delays and school failure. The program operated at a single site between 1972 and 1985, in North Carolina, and underwent numerous assessments of its long-term effects on participants.
The Abecedarian Project involved two components: a preschool intervention and a school-age intervention. The preschool program was offered in a day care center setting, the main goal of which was to create an educational, stimulating, and structured environment to promote growth and learning and to enhance school readiness. The curriculum was designed to enhance cognitive and linguistic development and to provide an enriched language environment that was responsive to children's needs and interests. In addition, children received nutritional supplements and disposable diapers, along with pediatric care and supportive social work services. Infants began attending the preschool program between six weeks and three months of age, and continued until entry into kindergarten. Children attended the day care center six to eight hours per day, five days per week, 50 weeks per year. After the children turned three years old, they received a more structured set of educational curricula, which became increasingly similar to programs in the local public kindergartens as the children grew older.
The school-age intervention began at kindergarten entry and continued through the first three years of elementary school. A resource teacher was assigned to each child and family for the length of the program. The resource teacher prepared an individualized set of home activities to supplement the school's basic curriculum in reading and math, taught parents how to use these activities with their children, tutored children directly, met regularly with classroom teachers to ensure that home activities aligned with the skills being taught in the classroom, served as a consultant for the classroom teacher when problems arose, and advocated for the child and family within the school and community. Resource teachers made approximately 17 school visits and approximately 15 home visits per year for each child. In addition, they offered children a variety of summertime supports, including summer activity packets, help in arranging summer camp experiences, trips to the public library, and tutoring in reading skills.
The Abecedarian Project focused its enrollment efforts on at-risk families with infants up to six months of age. At-risk families were referred to the project through local hospitals, clinics, the Department of Social Services, and other referral sources. These families were visited at home by a staff member, who explained the program to them and determined whether or not they met certain selection criteria. If so, mothers were invited to the Frank Porter Graham Center at the University of North Carolina at Chapel Hill for an interview and psychological assessment. They were screened using the High Risk Index, which included 13 socio-demographic factors associated with poor intellectual and scholastic progress. The scores on these factors were weighted and combined to arrive at a total for each family. If a family scored 11 or more points, that family was judged to be at elevated risk and eligible for inclusion in the study.
The families taking part in the evaluated program were low-income and predominantly African-American (98 percent). The majority of the families were headed by a single mother (83 percent) with an average age of 20 years, an average IQ of 85 (15th percentile), and a low level of education. Target children were predominantly firstborns and included slightly more females (53 percent) than males.
The Abecedarian project was a two-part intervention, consisting of a preschool intervention and a primary school-aged intervention.
Admission to the original preschool intervention took place over a five-year period, from 1972 to 1977, with four groups of approximately 28 children each being admitted during that time span. Children and families were matched on the basis of High Risk Index scores and were then randomized to preschool intervention or control groups from birth to five years. The final sample included 111 infants from 109 families at baseline, 57 of whom were randomly assigned to the intervention group and 54 to the control group. Four children withdrew early in the study, leaving 107 children in the initial analysis sample (Ramey and Campbell, 1984).
In the intervention for primary school-age children, children in the preschool intervention and control groups were further randomized into primary school intervention and control groups. Prior to kindergarten entry, pairs of children within the preschool intervention and control groups were equated on the basis of their 48-month IQ scores, with one of each pair randomly assigned to the school-age intervention group for the first three years of school and the other to the control group. This research design resulted in four separate groups for comparison. On admission to kindergarten, 96 children remained in the study, and, by the end of the follow-up study period, data on 92 children were available (Horacek et al., 1987).
Therefore, the participants consisted of children who had undergone one of the following:
- eight years of intervention—five in preschool and three in primary school (the experimental/experimental [or EE] group with 25 children)
- five years of intervention in preschool only (the experimental/control [or EC] group with 24 children)
- three years of primary school intervention only (the control/experimental [or CE] group with 21 children)
- no educational intervention at all (the control/control [or CC] group with 22 children).
Studies assessing outcomes for children after primary school were analyzed in one of two (or both) ways. Outcomes were analyzed either among all four groups of children, or by collapsing the preschool experimental groups (EE and EC) together to form a single preschool intervention group and collapsing the preschool control groups (CE and CC) together to form a single preschool control group.
Subsequent to both the original set of studies, which collected data in preschool and at the end of the kindergarten year, data have been obtained and analyzed for the participants at ages 8, 12, 15, 18, and 21 years. Outcomes assessed included the following:
- Early childhood outcomes were assessed at six-month intervals from six months of age through 54 months (4.5 years old) (Ramey et al., 1984; Burchinal, Lee, and Ramey, 1989; Martin, Ramey, and Ramey, 1990):
- Bayley Scales of Infant Development
- Stanford-Binet Intelligence Scale (IQ)
- McCarthy Scales of Children's Abilities (to test the development of specific skills at specific ages)
- Wechsler Preschool and Primary Scale of Intelligence (WPPSI).
- Primary school-age outcomes were assessed at ages 5, 6, 7, and 8 (Horacek et al., 1987; Ramey and Campbell, 1994):
- grade retention
- Woodcock-Johnson achievement test scores in reading, math, written language, and knowledge
- Wechsler Preschool and Primary Intelligence Scale for Children (WPPSI)
- Middle school- and high school-age outcomes were assessed at ages 12, 15, and 18 (Campbell and Ramey, 1994; Campbell and Ramey, 1995; Clarke and Campbell, 1998):
- grade retention
- Wechsler Intelligence Scale for Children (WISC-R)
- Delinquency (including number of convictions for misdemeanors or felonies and amount of time incarcerated or on probation)
- Adult outcomes were assessed at age 21 (Campbell et al., 2002; Muennig et al., 2011):
- Wechsler Adult Intelligence Scale (WAIS-R)
- use of alcohol, tobacco, marijuana, cocaine, or other illegal drugs
- education levels, including attendance at a four-year college
- teen pregnancy
- conviction and incarceration rates
- health composite scale, including
- Brief Symptom Inventory depression scale
- number of hospitalizations in previous year
- self-reported health problems since age 15
- behavioral risk factor composite scale, including 11 measures concerning traffic safety, drug use, and access to primary care.
Key Evaluation Findings
Early Childhood Outcomes
The initial study of the Abecedarian Project (Ramey and Campbell, 1984) found that the preschool intervention group scored significantly higher than the control group on the following measures:
- the Bayley Mental Development Index at 18 months (but not at 6 or 12 months)
- IQ at 24, 36, and 48 months
- the McCarthy General Cognitive Index at 42 and 54 months
- the McCarthy Verbal Scale Index at 30, 42, and 54 months
- the McCarthy Perceptual-Performance Scale Index at 42 and 54 months
- the McCarthy Quantitative Scale Index at 42 and 54 months
- the McCarthy Memory Scale Index at 54 months (but not at 42 months).
No significant differences were found for motor skill development at any of the measurement intervals.
A second study analyzing data from the first 54 months of the study (Martin, Ramey, and Ramey, 1990), found that
- The intervention groups had higher IQ scores than the control groups even when the effects of maternal IQ and home environment were controlled for.
- The positive impact of educational day care was especially pronounced for the children whose mothers scored lowest on maternal IQ.
The third preschool study (Burchinal, Lee, and Ramey, 1989) used three groups for analysis purposes, comparing the Abecedarian intervention group with both a no-day-care control group and a community day care control group. The researchers found that the intervention group children scored significantly higher than both the community group and the no-day-care group children over time on the following measures:
- the Bayley Mental Development Index at 6, 12, and 18 months
- IQ tests at 24, 36, and 48 months
- the McCarthy General Cognitive Index at 42 and 54 months.
In addition, the differences between the intervention group and no-day-care group were larger than the differences between the intervention group and the community day care group. The community day care group outscored the no-day-care group on all measures at all time intervals.
Primary School Findings
The first study following the children to age 8 (Horacek et al., 1987) found that by the end of their third year in school,
- Both the preschool intervention and the primary school intervention were associated with lower grade retention. Specifically,
- 50 percent of the children who had received no intervention at either level (the CC children) and 38 percent of the children who had received no preschool intervention but had received the primary school intervention (the CE children) had failed at least one grade in school.
- In comparison, 29 percent of the children who had received the preschool intervention but not the primary school intervention (the EC children) and 16 percent of the children who had received intervention at both levels (the EE children) had failed a grade.
- When achievement test results in reading were compared, scores were shown to have improved with increasing length of time spent in the Abecedarian program intervention. That is, the group with no intervention (CC) exhibited the poorest scores (75 percent of the group was in the bottom quartile of reading scores), while the group with eight years of intervention (EE) demonstrated the best performance (44 percent of the group was in the bottom quartile of reading scores).
- Similarly for math scores, 50 percent of the CC group children scored in the lowest quartile, compared with 28 percent of the children in the EE group, while the EC and CE groups fell somewhere in between.
Another study assessing outcomes up to age 8 (Ramey and Campbell, 1994) found that
- The preschool intervention groups (EE and EC) scored significantly higher, on average, on the Wechsler Intelligence Scale, relative to with the preschool control groups (CE and CC), across time, i.e., at measurements taken at 60, 78, and 96 months.
- Educational intervention that began during the primary school grades (i.e., without the preschool intervention) was not associated with positive effects on Wechsler Intelligence Scale performance.
Middle School- and High School-Age Outcomes
A follow-up study to age 12 (Campbell and Ramey, 1994) found a significant effect for
- The preschool intervention, but not the school-age intervention, on children's overall Wechsler Intelligence score (verbal and performance intelligence combined).
- The preschool intervention on Wechsler verbal intelligence (e.g., vocabulary, comprehension, arithmetic) but not on Wechsler performance intelligence (e.g., picture completion, object assembly, mazes)
- The school-age intervention on performance intelligence but not on verbal intelligence.
- The preschool intervention on reading, math, knowledge, and written language scores. There were no significant effects found for the school-age intervention on these measures.
- Grade retention, with children from the preschool intervention group retained in grade less often. During the first seven years of school, 32 percent of EE students and 38 percent of EC students were retained in grade, compared with 52 percent of CE students and 57 percent of CC students.
A follow-up at age 15 (Campbell and Ramey, 1995) found the following:
- Higher Wechsler Intelligence Scale scores over time were positively related to the preschool intervention. EE and EC students had overall average intelligence scores of 99.4 and 100.2, respectively, while CE and CC students had average scores of 88.9 and 93.1, respectively.
- The preschool intervention group earned significantly higher scores on Woodcock-Johnson measures of reading and mathematics than did the control group.
- Significantly fewer preschool intervention group students were retained in grade during the first ten years of school, compared with the control group students (31.2 percent compared with 54.5 percent).
A follow-up at age 18 focusing on criminal activity (Clarke and Campbell, 1998) found no significant differences between the preschool group and no-preschool group on any measures of crime or arrests, including age at first criminal charge.
A follow-up at age 21 (Campbell et al., 2002) found significant differences favoring the preschool intervention group over the control group for
- the full-scale Wechsler intelligence test and verbal intelligence test
- Woodcock-Johnson scales for broad reading, letter-word identification, broad mathematics, calculation, reading-grade equivalent, and math-grade equivalent
- average years of education by age 21 (12.2 versus 11.6 years)
- percentage attending or having attended a four-year college (35.9 percent versus 13.7%)
- percentage having become teenaged parents (26 percent versus 45%)
- percentage self-reporting marijuana use within the past 30 days (18 percent versus 39%)
- percentage indicating they were regular cigarette smokers (39 percent versus 55%).
No significant differences were found between the preschool intervention and control groups on
- the Wechsler performance intelligence test
- percentage graduating high school
- percentage currently employed
- conviction and incarceration rates
- use of illegal drugs (other than marijuana)
- binge drinking or use of alcohol in the past 30 days.
An analysis of the age-21 follow-up data examining the effects of the preschool intervention (Muennig et al., 2011) found the following:
- Health scale
- Scores on the overall health composite scale score (a composite index including depression symptoms, prior year hospitalizations, and self-reported health) were significantly improved in the treatment group relative to the control group.
- None of the three individual elements that comprised the health scale were significantly different when comparing the treatment group with the control group.
- Behavioral risk factor scale
- Scores on the overall behavioral risk composite scale (composed of 11 measures regarding traffic safety, drug use, and access to primary care) were significantly improved in the treatment group compared with the control group.
- When considered individually, three of the 11 measures on the behavioral risk factor scale were higher for the treatment group. All three significantly different measures indicated improvement in the treatment group relative to the control group. These measures included age at which participant first began smoking, age at which participant first tried marijuana, and frequency of marijuana use in the past month.
Finally, an additional analysis of the age-21 data examined the relationship between project participation and mental health outcomes (McLaughlin et al., 2007). This analysis found a significant program effect on depression as measured by the Brief Symptom Inventory (BSI), finding that participation in the Abecedarian project was associated with an average reduction of over 4 points on the BSI as compared to the control group. This finding appears to be contrary to the findings for the same measure reported in Muennig et al. (2011), but it should be noted that the McLaughlin et al. paper considered the interaction between early childhood intervention and the quality of the early home environment as joint predictors of self-reported depressive symptoms in young adults. McLaughlin et al. showed that the early intervention reduced the impact of a high risk home environment on the later depressive feelings of persons from high-risk backgrounds.
Public and private child care programs and elementary schools
Early phases of the research were primarily funded by a series of grants from
- the Mental Retardation and Developmental Disabilities Branch of the National Institutes of Child Health and Human Development
- the Department of Human Resources of the State of North Carolina.
The age-21 follow-up study of the Abecedarian program was funded jointly by
- the Maternal and Child Health Bureau of the Department of Health and Human Services
- the National Institute on Early Childhood Development and Education of the Office of Educational Research and Improvement, Department of Education
- the David and Lucile Packard Foundation
- the Frank Porter Graham Child Development Center.
A cost-benefit analysis of the Abecedarian program (Masse and Barnett, 2002) determined that the average annual cost of the program is about $17,099 per child (in 2011 dollars, adjusted for inflation). The researchers concluded that the long-term benefits of the program, including future earnings and maternal earnings as well as health benefits from a potential decrease in smoking, outweighed costs by a factor of four dollars for every one dollar spent.
- The day care center operated from 7:45 a.m. to 5:30 p.m., five days per week, 50 weeks per year. Free transportation was provided to families if needed.
- Infants up to walking age were cared for in a nursery area, while toddlers and preschoolers were grouped in other areas according to age and developmental levels.
- Families were encouraged to participate in parent group sessions on topics related to parenting and family development.
- Social workers were available to provide assistance to parents with such issues as housing and social services as well as personal counseling.
- Pediatric care was provided by a team of on-site research nurses and pediatricians.
- The curriculum for the first three years of life was developed by Sparling and Lewis (1981). The curriculum consisted of language, motor, social, and cognitive skill development, and these items were individually presented to each child. With increasing age, the curriculum was sometimes presented in small groups.
- After the age of 3, other standard preschool curricula were introduced in the day care center, such as the Peabody Early Experiences Kit (Dunn et al., 1976), Bridge-to-Reading (Greenberg and Epstein, 1973), the GOAL math program (Karnes, 1973), the My Friends and Me social skills program (Davis, 1977), and the Wallach and Wallach (1976) pre-phonics reading program.
- The preschool program focused on the development of communication skills, and each child was conversed with and read to daily. Derived from programs developed by Tough (1976) and Blank (1973), the program emphasized teachers' informative and nondirective verbal interchanges with the children.
Curriculum: Primary School
- No specific curriculum was used for the school-age intervention, as the content depended on the curricula used by the local public schools.
- The resource teachers met with classroom teachers to learn which concepts (in mathematics and reading) were currently being taught in school, after which they designed enjoyable and compatible home activities. The resource teacher discussed these activities with the children's families and encouraged parents to use them with their children on a regular basis.
- In a typical year, approximately 60 different learning activities were designed for each child. The average amount of time parents reported working with their children on the activities was about 15 minutes per day.
- In the Abecedarian Project, the preschool staff included a director, 12 teachers and aides, and an administrative staff. Teacher-child ratios began at one-to-three in the nursery and gradually increased to one-to-six in the last preschool year.
- The teaching staff varied in their professional background from those with graduate degrees in early childhood education to paraprofessionals, but all had had extensive experience in working with young children.
- In-service training and technical assistance were provided to the educational staff through periodic on-site programs by educational, psychological, and pediatric consultants and by teachers' participation in local and national educational conferences and workshops.
- For the school-age intervention, the resource teachers were graduate-level teachers with backgrounds in primary education who worked with approximately 12 children each per year.
The Abecedarian Project is not currently in operation, and there are no available materials to support replication.
Issues to Consider
This program received a "proven" rating. The evaluation of the program used rigorous standards, including a randomized experimental design and longitudinal follow-up, and the participants experienced significant and sizeable gains across most of the cognitive and academic performance outcomes.
Although the Abecedarian Project did not set out to select at-risk families based on race, 98 percent of the resulting group of children was African-American. In addition, 83 percent of the families included in the intervention group were female-headed and were otherwise characterized by extreme poverty, unstable employment, and low educational attainment for mothers and fathers. It is unclear whether similar results would be obtained with other types of families.
In addition, the experiment took place in a small, relatively affluent university town with a wide range of human services agencies, including public hospitals and programs providing housing, fuel subsidies, food supplements, and job training. Thus, a relatively high degree of social, fiscal, and material supports were already available to participants (both intervention and control), and results may not be the same in cities with markedly different features.
Besides the main finding of significant effects for the Abecedarian program as a whole at enhancing long-term IQ and academic achievement, another important conclusion to be drawn from the evaluations is that five years of the Abecedarian preschool intervention is almost equally as effective as five years of the preschool program with a three-year primary school follow-up, and definitely more effective than the three-year Abecedarian primary school intervention alone.
An age-21 follow-up analysis was conducted examining the relationship between depressive symptoms in young adults, the quality of the early home environment, and participation in the intervention. Authors found a significant relationship between the quality of the home environment and depression in the control group, but not in the treatment group, suggesting that the program mitigated any negative effects of a low-quality home environment (McLaughlin et al., 2007).
The Abecedarian Project was implemented at a single site in North Carolina.
Frances Campbell, Ph.D.
Frank Porter Graham Child Development Center
University of North Carolina
Campus Box 8180
105 Smith Level Road
Chapel Hill, NC 27599-8180
Fax: (919) 966-7532
The Abecedarian Project homepage, from the Frank Porter Graham Child Development Institute at the University of North Carolina at Chapel Hill: http://www.fpg.unc.edu/~abc/
Teaching Learning in the Preschool: A Dialogue Approach,
Columbus, Ohio: Merrill, 1973.
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Campbell, Frances A., and Craig T. Ramey, "Effects of Early Intervention on Intellectual and Academic Achievement: A Follow-Up Study of Children from Low-Income Families," Child Development, Vol. 65, 1994, pp. 684-698.
Campbell, Frances A., Craig T. Ramey, Elizabeth Pungello, Joseph Sparling, and Shari Miller-Johnson, "Early Childhood Education: Young Adult Outcomes from the Abecedarian Project," Applied Developmental Science, Vol. 6, No. 1, 2002, pp. 42-57.
Clarke, Stevens H., and Frances A. Campbell, "Can Intervention Early Prevent Crime Later? The Abecedarian Project Compared with Other Programs," Early Childhood Research Quarterly, Vol. 13, No. 2, 1998, pp. 31-343.
Davis, Duane Q., My Friends and Me, Circle Pines, Minn.: American Guidance Service, 1977.
Dunn, Lloyd M., Lillie T. Chun, Doris C. Crowell, Leota M. Dunn, Lynne Grossman Halevi, and Eleanor R. Yackel, Peabody Early Experiences Kit, Circle Pines, Minn.: American Guidance Service, 1976.
Greenberg, Polly, and Bea Epstein, Bridge-to-Reading: Curriculum for Pre-School, Kindergarten, and First Grade, Morristown, N.J.: General Learning Corp, 1973.
Horacek, H. Joseph, Craig T. Ramey, Frances A. Campbell, Kathleen P. Hoffmann, and Robert H. Fletcher, "Predicting School Failure and Assessing Early Intervention with High-Risk Children," American Academy of Child and Adolescent Psychiatry, Vol. 26, No. 5, 1987, pp. 758-763.
Karnes Merle B., GOAL Program: Mathematical Concepts, Springfield, Mass.: Milton-Bradley, 1973.
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McLaughlin, Andrea, Frances A. Campbell, Elizabeth P. Pungello, and Martie Skinner, "Depressive Symptoms in Young Adults: The Influences of the Early Home Environment and Early Educational Child Care," Child Development, Vol. 78, No. 3, May/June 2007, pp. 746-756.
Muennig, Peter, Dylan Robertson, Gretchen Johnson, Frances Campbell, Elizabeth P. Pungello, and Matthew Neidell, "The Effect of an Early Education Program on Adult Health: The Carolina Abecedarian Project Randomized Controlled Trial," American Journal of Public Health, Vol. 101, No. 3, 2011, pp. 512-516.
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Ramey, Craig T., and Frances A. Campbell, "Preventive Education for High-Risk Children: Cognitive Consequences of the Carolina Abecedarian Project," American Journal of Mental Deficiency, Vol. 88, No. 5, 1984, pp. 515-523.
Sparling, Joseph, and Isabelle Lewis, Learning Games for the First Three Years: A Program for Parent/Center Partnership, New York: Walker Educational Book Corp, 1981.
Tough, Joan, Listening to Children Talking, London, UK: Word Lock Educational, 1976.
Wallach, Lisa, and Michael A. Wallach, The Teaching of All Children to Read Kit, Chicago: University of Chicago Press, 1976.