Growth of the Asai child of the Madang district of New Guinea

Growth rates and life histories in twenty-two small-scale societies

This study investigates variation in body growth (cross-sectional height and weight velocity) among a sample of 22 small-scale societies. Considerable variation in growth exists among hunter-gatherers that overlaps heavily with growth trajectories present in groups focusing more on horticulture. Intergroup variation tends to track environmental conditions, with societies under more favorable conditions displaying faster growth and earlier puberty. In addition, faster/earlier development in females is correlated with higher mortality. For example, African "Pygmies," Philippine "Negritos," and the Hiwi of Venezuela are characterized by relatively fast child-juvenile growth for their adult body size (used as a proxy for energetic availability). In these societies, subadult survival is low, and puberty, menarche, and first reproduction are relatively early (given their adult body size), suggesting selective pressure for accelerated development in the face of higher mortality. In sum, the origin and maintenance of different human ontogenies may require explanations invoking both environmental constraints and selective pressures.

Climatic influences on human body size and proportions: ecological adaptations and secular trends

This study reevaluates the long-standing observation that human morphology varies with climate. Data on body mass, the body mass index [BMI; mass (kg)/stature (m)2], the surface area/body mass ratio, and relative sitting height (RSH; sitting height/stature) were obtained for 223 male samples and 195 female samples derived from studies published since D.F. Roberts' landmark paper "Body weight, race, and climate" in 1953 (Am. J. Phys. Anthropol. 11:533-558). Current analyses indicate that body mass varies inversely with mean annual temperature in males (r=-0.27, P < 0.001) and females (r=-0.28, P < 0.001), as does the BMI (males: r=-0.22, P=0.001; females: r=-0.30, P < 0.001). The surface area/body mass ratio is positively correlated with temperature in both sexes (males: r=0.29, P < 0.001; females: r=0.34, P < 0.001), whereas the relationship between RSH and temperature is negative (males: r=-0.37, P < 0.001; females: r=-0.46, P < 0.001). These results are consistent with previous work showing that humans follow the ecological rules of Bergmann and Allen. However, the slope of the best-fit regressions between measures of body mass (i.e., mass, BMI, and surface area/mass) and temperature are more modest than those presented by Roberts. These differences appear to be attributable to secular trends in mass, particularly among tropical populations. Body mass and the BMI have increased over the last 40 years, whereas the surface area/body mass ratio has decreased. These findings indicate that, although climatic factors continue to be significant correlates of world-wide variation in human body size and morphology, differential changes in nutrition among tropical, developing world populations have moderated their influence.

The Ok Tedi Health and Nutrition Project, Papua New Guinea: physique, growth and nutritional status of the Wopkaimin of the Star Mountains

A survey was carried out to establish baseline anthropometric and health data in the Wopkaimin, a small group of Mountain Ok-speaking hunter-horticulturalists who live in a remote and isolated part of the Highland fringe of Papua New Guinea, where a major gold and copper mine is being developed. Malaria is hyperendemic in the region and infant mortality has been estimated at approximately 230 per thousand. A 79% sample of the population was examined and the results of the anthropometric survey are reported. Wopkaimin childrens' heights and weights are well below the 50th percentile of British standards throughout growth; at maturity boys' weights and girls' heights and weights are at or below the 3rd percentile, and boys' weights are just above the 10th percentile. Wopkaimin children lag far behind British children in percentage of adult height achieved at all ages, and appear to attain maturity at least four years later. This relatively slow growth and short adult stature may represent an adaptive response to chronic nutritional deprivation, for which there is evidence from skinfold thickness and arm circumference measurements. Younger adults are significntly taller, heavier, fatter and more muscular than older adults; possible explanations for this are discussed. Within the sample, individuals living in villages less than a day's walk from the mine town are significantly taller, heavier and fatter than those living further away, and there are also similar significant anthropometric differences between employed and unemployed men. Ready food availability which has come with the mine development appears to be the most likely explanation for these differences. A continuing study of changing patterns of health and nutrition in the area has been initiated.