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Early ChildhoodHuman capitalPositive

Jamaica Stunting Study — Stimulation + Nutrition

University of the West Indies / World Bank · Kingston, Jamaica · 1986

Summary

The Jamaica study is remarkable for its long follow-up and the specificity of its finding: psychosocial stimulation (play, reading, structured interaction with caregivers) completely closed the 20-year earnings gap between stunted and non-stunted children, while nutritional supplementation alone did not. The study demonstrated that cognitive deprivation—not just physical malnutrition—drives the long-term effects of childhood stunting, and that it is reversible through relatively low-cost stimulation programs.

Research question

"Can psychosocial stimulation and nutritional supplementation overcome early childhood stunting's effects on development and adult earnings?"

Methodology

Intervention

Four arms: control, nutritional supplementation, psychosocial stimulation, stimulation + supplementation

Assignment

Randomized controlled trial (child)

Sample size

129 stunted children, followed to adulthood

Primary outcome

Cognitive development, educational attainment, adult earnings

Effect estimate

Stimulation arm: +42% adult earnings compared to control; fully closed the earnings gap with non-stunted peers after 20 years; supplementation alone had no significant long-term effect

Decision

Results shaped UNICEF and World Bank early childhood development policy globally; stimulation programs integrated into nutrition interventions worldwide

Result

Positive

Stimulation arm: +42% adult earnings compared to control; fully closed the earnings gap with non-stunted peers after 20 years; supplementation alone had no significant long-term effect

Evidence strength

Strong

Randomized controlled trial with large sample.

Replication status

Partially replicated

Institution

University of the West Indies / World Bank

Location

Kingston, Jamaica

Year

1986

Policy area

Early Childhood

Mechanism

Human capital

More from these institutions

Other trials of this mechanism

Cite this entry

University of the West Indies / World Bank. (1986). Jamaica Stunting Study — Stimulation + Nutrition. The Experiment Society Registry. Retrieved from https://www.experimentsociety.org/registry/jamaica-stunting-stimulation (primary report: https://www.sciencemag.org/doi/10.1126/science.1251178)

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