Adaptive significance of small body size: strength and motor performance of school children in Mexico and Papua New Guinea.
The postulated superior functional efficiency in association with reduced body size under conditions of chronic protein-energy undernutrition was considered in school children from rural Mexico and coastal Papua New Guinea. Grip strength and three measures of motor performance were measured in cross-sectional samples of children 6-16 years of age from a rural agricultural community in Oaxaca, Mexico, and from the coastal community Pere on Manus Island, Papua New Guinea. The strength and performance of a mixed-longitudinal sample of well nourished children from Philadelphia was used as a reference. The Oaxaca and Pere children are significantly shorter and lighter and are not as strong as the well nourished children. Motor performances of Pere children compare favorably to those of the better-nourished Philadelphia children, whereas those of the Oaxaca children are poorer. Throwing performance is more variable. When expressed relative to body size, strength is similar in the three samples, but the running and jumping performances of Pere children per unit body size are better than the relative performances of Oaxaca and Philadelphia children. Throwing performance per unit body size is better in the undernourished children. The influence of age, stature, and weight on the performance of Oaxaca and Pere children is generally similar to that for well nourished children. These results suggest that the hypothesized adaptive significance of small body size for the functional efficiency of populations living under conditions of chronic undernutrition varies between populations and with performance tasks.
Malina
R M
RM
Department of Anthropology, University of Texas at Austin 78712.
Little
B B
BB
Shoup
R F
RF
Buschang
P H
PH
D000293:Adolescent; D001824:Body Constitution; D001835:Body Weight; D002648:Child; D002664:Child Nutritional Physiological Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D009048:Motor Skills / Q000502:physiology*; D010219:Papua New Guinea; D010414:Pennsylvania; D010809:Physical Fitness