Children tend to resemble their parents in stature, body proportions, body composition, and rate of development. It may be assumed that barring the action of obvious environmental influences on growth (such as chronic illness or long-term malnutrition) these resemblances reflect the influence of genes that parents contribute to their biological offspring. A study published by Prokopec and Lhotska (1989), based on a sample of 81 boys and 78 girls, is an example of this view. The subjects, all from Prague, were measured annually from birth to age 20 years. The PreeceBaines growth curve was fit to the longitudinal data of each subject. From these fitted curves for all the boys and girls, the three tallest, the three shortest, the three slowest maturing, and the three fastest maturing of each sex were selected. None of these extreme cases was known to have any major chronic or acute diseases. Neither the subject’s history of common childhood diseases, nor the occupation of the fathers had an effect, positive or negative, on growth and development. In contrast, the midparent height did predict the adult stature of offspring. Mid-parent height is the average of the stature of the mother and the father. Inspection of the Preece-Baines curves showed that tall or short stature at age 20 could be predicted from stature at age four years. The positive impact of mid-parent stature on offspring growth and the predictability of adult height from stature at age four are prima facia evidence for the role of heredity. Moreover, these findings attest to the early establishment of individual patterns of growth and their stability over time.Facultad de Ciencias Naturales y Museo