Abstract:
Mpeta et al. recently published a paper in which they used secular trends in stature of South Africans to make
inferences about living standards. The use of documentation of living standards and the fluctuations thereof as a
result of economic growth to explain the secular changes observed in height is a viable approach. The authors gave
an excellent review of the history of South Africa and the differences in living conditions that existed between the
population groups. However, we believe the biological data were incorrectly used, in order to support inferences
regarding the socio-economic situation. The average stature of a population group indeed has a direct relationship
with the living conditions and the per capita income of the individuals. For example, decreased stature may be
an indicator of nutritional deprivation as a result of a lower income. However, it is important to note that there
are many other factors that can influence stature. The size and shape of human bodies vary considerably among
population groups across the world and body size is not fixed. Changes in height are continually taking place. In
this study the authors repeatedly imply that the living standards can be explained by differences and changes in
height, e.g. ‘by analysing the mean height…, we shed light on the standard of living’ (p. 1); ‘black living standards
as measured by height’ (p. 1). Height should not be used simplistically to indicate the standard of living or socioeconomic
status as it is influenced by too many other variables such as climate, diet, genetics/gene flow, family
size and urbanisation. Rather, standard of living should be used, as one of many possible factors, to explain
the observed differences in height.
