Secular change: Somatic comparisons of urban and rural black male children and youths living in central South Carolina.

Somatic data were collected during 1988-1989 on 260 black males, ages 6, 9, and 15 years, living in Calhoun County in rural central South Carolina. Eight measures of body size, four estimates of body form, two skinfold thicknesses, and body mass index (BMI) were analyzed for central tendency and variability. Comparisons were made with earlier samples of black boys measured in Columbia City, South Carolina, during 1974-1977. At ages 9 and 15 years, the Calhoun County boys exceed Columbia City boys in standing height, sitting height, lower limb height, arm girth, and body weight. Measures of body form were similar for both groups. Among worldwide comparisons, Calhoun County boys exceed all groups in standing height and body weight. Comparisons with earlier means indicate secular gains and estimates of their magnitude. © 1993 Wiley-Liss, Inc.