In this chapter, we shall examine the influences of environment and heredity upon the growth and development of working capacity, considering also problems of methodology, activity patterns and facets of athletic performance peculiar to the child.

Considerations of methodology

Types of survey

There are three potential approaches to the study of growth and development (Shephard & Rode, 1975). The traditional method is well exemplified by the IBP study in Saskatoon (Bailey et al., 1914b) and an analogous study of French Canadian schoolchildren (Shephard et al., 1974b). Cohorts of children are followed in a longitudinal fashion, with observations being repeated at intervals of six to twelve months, for a total period of ten to fifteen years. This technique allows a rather precise definition of growth spurts, but it is expensive and time-consuming, particularly if the tests to be used are more than simple measurements of body dimensions. Further, in primitive societies affected by rapid acculturation, there is a danger that normal processes of growth will be confounded with changes brought about by alterations in habitual physical activity, diet and other environmental variables.

The cross-sectional survey is a much cheaper alternative, used for example in many of the Czechoslovakian and Japanese contributions to the IBP (Seliger, 1970; Hasegawa et al., 1966; Ikai, Shindo & Miyamura, 1970; Matsui et al., 1971). In a relatively stable industrialized society, a useful overall picture of development is obtained.