Psychosocial stimulation to stunted toddlers living in poverty has dramatic long-term effects

This study finds large effects on the earnings of participants from a
randomized intervention that gave psychosocial stimulation to stunted
Jamaican toddlers living in poverty. The intervention consisted of
one-hour weekly visits from community Jamaican health workers over a
2-year period that taught parenting skills and encouraged mothers to
interact and play with their children in ways that would develop
their children's cognitive and personality skills.

The authors of this study re-interviewed the study participants 20
years after the intervention.

Stimulation increased the average earnings of participants by 42 percent.
Treatment group earnings caught up to the earnings of a matched
non-stunted comparison group. These findings show that psychosocial
stimulation early in childhood in disadvantaged settings can have
substantial effects on labor market outcomes and reduce later life
inequality.