On a recent visit with family to an amusement park, a sign welcoming customers to one of the gyrating rides announced a vetting criterion for proceeding and partaking of the thrills: ‘Riders Must Be At Least This Tall.’ The sign pictured a monkey pointing to an elongated horizontal banana about 120 cm from the ground. I wondered at the time about the actual scientific rationale for such a height requirement, inter alia, estimating body weight for mechanical counterbalance, estimating age for appropriate behaviour, estimating sitting height for reaching the head rest, estimating minimum waist girth for the safety belt. In any case, this rather pedestrian application of child growth data, probably for some human engineering or safety purpose, is an example of the widely divergent applications of data pertaining to growth and maturation of children.
Even though the actual rationales and applications of growth data vary tremendously, to some degree, they all are grounded in and emanate from auxological studies. Careful measurement, development of relevant theory and statistical analysis are required to answer the myriad research questions related to particular applications. It is, then, the collective scientific, biomedical and practical importance of the many applications that provides the justification for studying child growth and maturation.
In this chapter, I shall briefly present some important types of postnatal growth studies and their chief contributions. At selected junctures I shall elaborate on issues pertaining to the nature of growth and maturation, with particular emphasis on underlying principles and applications related to child health.