Following the decision of the International Union of Biological Sciences in 1982 to embark on a new research programme, “The Decade of the Tropics”, the importance of including some themes relating to human biology was immediately apparent. There are so many human problems that are outstanding among tropical populations, and for a significant contribution to be made by the programme it would be necessary to concentrate effort on a few of the more important topics. Canvassing human biologists throughout the world on those investigations currently in progress and those thought important to develop, brought a list of some fifty projects. From these, two areas emerged as requiring urgent attention: one concerned the study of genetic variability, whilst the other concerned variations in working capacity and factors affecting it in tropical populations. To provide a critical review of present knowledge on work performance in the tropics, which would help to identify areas for further research, a meeting of scientists of high international standing was held at the CIBA Foundation in London on December 13th and 14th, 1984. The papers discussed then are published in the present volume.

For the purpose of the scientific meeting, the topics were arranged under six general headings: measurement of working capacity in populations; functional consequences of malnutrition; growth, stature and muscular efficiency; ethnic differences in working capacity; energy expenditure and endemic disease; and research models in tropical ecosystems. The present volume retains this framework, and all the studies reported contain new research carried out during the last ten years.