Children’s growth in an adaptive framework: explaining the growth patterns of American slaves and other historical populations

This article presents a new adaptive framework for understanding children’s growth in the past. Drawing upon the recent work on adaptive responses in relation to growth, it presents prenatal and postnatal adaptive mechanisms that affect the growth patterns of children. The most novel adaptive response to the historical literature is the prenatal predictive adaptive response where the metabolism and growth trajectory of a child is programmed to match predicted conditions later in life. Having discussed the framework in detail, a reinterpretation of the growth pattern of American slaves is then suggested. It seems likely that a mismatch between relatively good conditions in utero and absolutely appalling conditions in infancy and early childhood led slave children to become extremely stunted by the age of three or four. However, after this age, slave children experienced catch-up growth because their immune systems had become more developed and because their diet improved tremendously and hookworm exposure was reduced. Thus, it seems that American slave children may have experienced substantial catch-up growth because they were prenatally programmed for a higher metabolism and growth trajectory. The article concludes by setting out some stylized facts about children’s growth in the past and pointing toward areas of future research.