Psychomotor performance of chilean infants from low socio-economic level during their second year of life

The psychomotor development of 1,406 low socioeconomic infants from Santiago, Chile, was examined. Four groups of infants were assessed: 12, 15, 18 and 21 months of age. Results indicated that as chronological age increased, the number of infants who fell into at-risk or delay categories increased.