The groundbreaking Abecedarian Project launched in 1972 at the UNC Frank Porter Graham Child Development Institute (FPG.) This pioneering randomized control trial (RCT) demonstrated that early care and education (ECE) experiences can lead to long-term positive impacts on educational, social-emotional, and health outcomes for children from low-income families that last into adulthood.

While the Abecedarian Project has been critically important in supporting the value of ECE programs, there has been a lack of implementation data to highlight which elements of the program were most impactful. This information can help inform how current ECE programs shape their classroom practices to provide long-lasting benefits similar to those afforded by the Abecedarian program. Current ECE programs show short-term impacts, but most studies show that, over time, these effects become diminished.

FPG Research Scientist Kylie Garber, PhD, and former FPG Senior Research Scientist, Peg Burchinal, PhD, led a team to address this deficit. The team’s findings, “Piecing together the puzzle: A mixed methods study of the Abecedarian Intervention,” were published online on October 1, 2025, in Early Childhood Research Quarterly. The team posits that the Abecedarian program’s emphasis on providing language-rich interactions in child-centered environments is likely the primary mechanism by which program participants improved their verbal skills, resulting in higher levels of education and higher household incomes later in life.

Abecedarian Project Background

In the Abecedarian study, four cohorts of individuals, born between 1972 and 1977, were randomly assigned as infants to either an early educational intervention group or control group. Children in the intervention group received a full-time, high-quality educational program in a childcare setting from infancy through age five while the control group received access to free diapers, formula, and child care. 

The Abecedarian interventions were designed around two organizing principles. Very young children thrive when they experience warm and supportive stable relationships with caregivers, and language is the most important skill for children growing up in poverty. FPG researchers followed participating children into adulthood, assessing them at ages 5, 8, 12, 15, 21, and 30, and in their mid-30s. Participants in the program have shown higher scores on measures of intelligence, more years of total education, and a greater likelihood of attending a four-year-college. In addition, these participants had higher-skilled jobs, fewer teen pregnancies, and more positive health outcomes.

Current Study

To familiarize themselves with the documented Abecedarian intervention components, the team conducted a literature review of peer-reviewed articles and published books about the study as well as FPG annual reports and progress reports. The team collected and reviewed study and center documents from UNC and FPG as well as grant proposals and project budgets. These documents helped the team develop interview questions about teaching practices, early childhood learning philosophies, and program design that were used when the team conducted oral history interviews. 

The research team interviewed 15 Abecedarian infant caregivers, lead and assistant teachers, child care program directors, and researchers and curriculum developers who worked at FPG between 1972 and 1982, the years when the Abecedarian intervention was conducted. These staff members who participated in this part of the qualitative study helped researchers corroborate which components of the Abecedarian program cited in the research literature were actually used in the classrooms.

The team then conducted a data analysis of the oral histories to identify which elements appeared to be integral to the Abecedarian program implementation from the staff’s perspective. The researchers identified four major themes: 

• a focus on language development; 
• child-centered environments; 
• no structured curriculum use in preschool; and
• one-on-one coaching for program staff. 

The interviews also revealed that the Abecedarian study implemented seven elements: 
stable and stimulating adult-child interactions; 

• full-time care; 
• free transportation to and from the child care center; 
• low adult-child ratios; 
• lead teachers with a minimum of a bachelor’s degree; 
• individualized instruction; and
• high-quality health and safety practices. 

A key component of the intervention was the use of complex conversations between teachers and children. This served to foster language development and scaffold learning. Teachers used routines, particularly at meals, as intentional time to engage with the children. 

Another important element of the Abecedarian intervention was the child-centered environments, which ensured that classrooms offered a wide range of learning materials arranged in predictable ways, enabling children to find and put away activities.  Structure was also key to the curriculum in the infant and toddler classrooms which helped these young children develop their cognitive and motor skills through activities geared to each developmental stage.

Program directors and research staff provided one-on-one coaching to staff members to help them learn new teaching practices and approaches to help children learn. By having knowledgeable and skilled mentors available in the building to provide informal coaching, the teaching staff felt supported and engaged.

After conducting the qualitative study, the researchers undertook a quantitative study whose sample included the participants in the original Abecedarian intervention. The results showed that Abecedarian led to increases in children’s verbal skills, which in turn facilitated higher educational attainment in adulthood. The current study suggests that the Abecedarian program also had an indirect effect on income for all participants in the treatment group due to the improvements in verbal ability in childhood and higher educational attainment in adulthood.

While researching the Abecedarian program, Garber and her colleagues also examined the Perry Preschool Project (PPP), another child care RCT launched 10 years before Abecedarian began. The Abecedarian program offered services to children in infancy while PPP participants began that program in preschool.  While Abecedarian was full time and year-round, PPP was just 2.5 hours a day, five days a week, during the school year. Although the programs differed in their design and mechanisms, they had similar impacts on the participants’ functioning as adults. Garber and her team found evidence that there are multiple pathways though which these ECE programs reduce intergenerational poverty. 

While it is unclear how the results from early intervention programs, such as Abecedarian and PPP, apply to current ECE efforts—since today’s programs are different with regard to size, funding, and standards—there are still lessons to be learned. One difference is the current focus on “constrained” skills, which require rote memorization and are absorbed relatively quickly, such as learning the alphabet. The researchers posit that unconstrained skills, such as verbal skills requiring more knowledge and experiences, may be necessary to maintain longer-terms gains from ECE programs.

“It was an honor to work with data from the Abecedarian Project because it has had such a huge impact on early care and education programs as we know them today,” said Garber. “Although our societal context has changed so much from that of the original study, this current study gave us the opportunity to understand what made the Abecedarian classrooms special and how we can bring that forward in today’s classrooms.” 

“It was an honor to work with data from the Abecedarian Project because it has had such a huge impact on early care and education programs as we know them today,” said Garber. “Although our societal context has changed so much from that of the original study, this current study gave us the opportunity to understand what made the Abecedarian classrooms special and how we can bring that forward in today’s classrooms.”