Adult stature in southern African Negroes - further evidence on the absence of a positive secular trend

Abstract

The continuing search for data bearing on secular changes of adult stature in disadvantaged or Third-World communities led to the analysis of two sets of data. One was unpublished but was kindly made available by Professor H.C. Seftel, and was based on a study of 5018 adult and sub-adult male black subjects living in Johannesburg. The other dealt with black miners and the relevant data on adult and sub-adult stature had been published by Dr J.G.D. Laing. Both sets of results were analysed by the method of age-ranking of the cross-sectional data and correcting them, where applicable, for 'personal shrinkage' after 30 years of age. The former results proved suitable for the analysis and the reduced data showed clear evidence that the Johannesburg popUlation concerned had not been subject to a secular trend towards increased adult mean stature over the period c. 1919 c. 1950. This is a further example, over and above those already adduced from studies in Asia, Africa, Meso- and South America. that many of the world's agrarian and pastoral communities have shown an absent or even a negative secular trend, during some of the time that First-World populations have shown a a positive secular trend. The data for black miners proved to be too heterogeneous for this approach to be applied validly to them.

S Afr Med J 1990; 78: 97-101.