An analysis of longitudinal data shows that there are marked changes in the variability of stature and stature velocity during growth in stature, as measured by the coefficient of variation. Variability in stature velocity tends to rise after birth but from age 2 years it gradually declines until the end of adolescence, once variation in the timing of adolescence is taken into account. Comparison of velocity variation in an affluent western society (UK) with velocity variation in two poorer societies (India and Thailand) shows the former to be systematically smaller.