Early Stimulation and Enhanced Preschool: A Randomized Trial

OBJECTIVES: To estimate the impacts of 2 interventions, early stimulation (ES) for children aged <3 years and enhanced preschool (EP) for children aged 3+ years, and their interactions. METHODS: In Odisha, India, 192 villages were randomly assigned to ES or to no ES. Within each village, about 8 mothers with children initially aged 7 to 16 months were enrolled, receiving ES or no ES accordingly (n = 1449). Subsequently, when children were aged similar to 3 years, the villages were rerandomized to either EP at Anganwadi centers or no EP. This yielded 4 groups: (1) ES and EP, (2) only ES, (3) only EP, and (4) no intervention. Trained Anganwadi workers ran the EP. Primary outcomes, measured at baseline and follow-up after similar to 1 year, were children's IQ (summarizing cognition, language, and executive functioning) and school readiness (SR). Secondary outcomes were home environments, caregivers' child-development knowledge. and preschool quality. RESULTS: Fifteen months after ES ended, onlyES had a sustained benefit on IQ (0.18 SD, P <.04) and on SR (0.13 SD, P <.08). Only EP improved IQ (0.17 SD, P <.04) and SR (0.24 SD, P <.01). Receiving both interventions improved IQ (0.24 SD, P <.01) and SR (0.21 SD, P <.01). No statistically significant interactions between the 2 interventions were observed. CONCLUSIONS: Both ES and EP increased IQ and SR. Only ES impacts were sustained for 15 months. Only EP resulted in considerable catch-up for children who did not receive only ES. The absence of significant complementarities should be investigated further because of its profound policy implications.

Automated summary

Both early stimulation (ES) and enhanced preschool (EP) interventions have positive impacts on children's IQ and school readiness (SR). Only ES effects are sustained for 15 months, while only EP results in significant catch-up for children who did not receive ES. There are no significant interactions between the two interventions.