Worldwide, 250 million children under five (43 percent) are not meeting their developmental potential because they lack adequate nutrition and cognitive stimulation in early childhood. Several parent support programs have shown significant benefits for children's development, but the programs...

We present results two years after the end of a group-based parenting intervention tested in a cluster randomized control trial in rural Kenya. The original program consisted of 16 fortnightly village-based sessions over 8 months and had large positive impacts on children's cognition and...