Adult Outcomes as a Function of an Early Childhood Educational Program: An Abecedarian Project Follow-Up
Campbell, F. A., Pungello, E. P., Miller-Johnson, S., Burchinal, M., et al. · 2012
grade Brctdeveloper-ledmixednumbers spot-checked
Sample
111 (57 T / 54 C); 101 assessed at age 30 (91% retention)
Population
Low-SES African-American children, Chapel Hill NC, entering at mean age 4.4 MONTHS; 8h/day, 5d/wk, 50wk/yr to school entry.
Design
The most intensive early-childhood RCT ever run (~$18,514/participant-year in 2014 USD; ~$92k total). Treatment also included two daily meals plus health care, so it is not a pure 'education' contrast.
Key findings
The most intensive early intervention ever tested moved attainment substantially (BA+ 23% vs 6%) and welfare receipt, but was NULL on income-to-needs and NULL on crime. Its small durable IQ effect sits at, not above, the environmental ceiling seen in adoption studies. Note the absolute numbers: the headline BA result is 12 people versus 3.
Counterfactual
NOT nothing: controls received iron-fortified formula, free diapers and social services; ~75% used lower-quality alternative childcare.
Genetic confound
Spitz's critique: the treatment group already led on the Bayley MDI at SIX MONTHS by roughly the eventual gap, suggesting baseline imbalance rather than a treatment effect on IQ. Ramey's reply is substantially ad hominem.
Replication notes
Abecedarian's ~+4.4 IQ points at 21 is the only durable IQ effect from a preschool RCT — but it is NOT unique in the literature: full adoption produces +4.41 (Kendler 2015) and schooling ~1-5 points/year (Ritchie & Tucker-Drob 2018). ~3-5 points looks like the general ceiling for whole-childhood environmental manipulations.
Cost
~$92,000 per participant total — the most expensive intervention in the database.
DOI / URL
10.1037/a0026644
Effects
| Outcome | Metric | Value | Measure | Timing | Vs | Horizon | Class |
|---|---|---|---|---|---|---|---|
| Years of education completed | years | 13.46 vs 12.31 (significant) | mixed | adult | active-alternative | adulthood | attainment |
| Bachelor's degree or higher by 30 | % | 23.1% vs 6.1% — i.e. roughly 12 people vs 3 people | mixed | adult | active-alternative | adulthood | attainment |
| Criminal conviction by 30 | % ever convicted | 27.5% vs 28.6% — NULL. Directly fails to replicate Perry's crime channel | mixed | adult | active-alternative | adulthood | behaviour |
| Income-to-needs ratio at 30 | ratio | NULL | mixed | adult | active-alternative | adulthood | attainment |
| Public assistance receipt at 30 | % | 3.9% vs 20.4% | mixed | adult | active-alternative | adulthood | attainment |
| IQ trajectory (wider Abecedarian literature) | IQ points T-C | ~1.08 SD at 18mo-4.5yr; shrinks DURING treatment; ~+4.7 at 12; ~+4.4 at 21 | standardized | adult | active-alternative | adulthood | g |
Cited by
- Perry Preschool and Abecedarian — what the famous studies actually establishmixedconf: mediumgc: low