Research in child development at the Tropical Metabolism Research Unit, Jamaica, has expanded from development of severely malnourished children, to undernourished and other disadvantaged children as well as school-aged children. This extensive work has provided increasing evidence of the importance of early childhood development and informed the work and policies of international agencies.

Aggressive and prosocial boys were studied. Many differences were detected, including neighbourhood and family factors. These should be the focus of interventions to reduce violence among boys.