The relationship of socioeconomic status and sex to body size, skeletal maturation, and cognitive status of Guatemala City schoolchildren.

Longitudinal data from a study of child development in Guatemala City were used to describe the influence of socioeconomic status and sex on physical and cognitive growth status. The correlation between the growth status variables was also analyzed. The sample included 144 Guatemalan children, 46 of low SES, 52 of middle SES, and 46 of high SES. The children were students in 5 urban primary schools. 3 physical variables, height, weight, and skeletal age, were measured annually from first to sixth grade. Two cognitive variables, general intelligence and reading ability, were measured in grades 1, 3, 4, or 5. Significant differences between SES groups existed for all variables. However, the differences in each grade were greater for the cognitive measures than for the physical measures. Compared with high SES children, middle SES boys and low SES boys and girls experienced significantly greater delayed growth in height than in weight or skeletal age. It is possible that these height delays may result in a permanent reduction in stature. The only consistently significant sex-related difference was for skeletal age; girls were more mature than boys in each grade. When SES was statistically controlled, there was no significant correlation between physical and cognitive growth status for girls and only a few moderate but statistically significant correlations for boys.