Height recovery
The forces that led to increasing average heights are difficult to pinpoint without additional evidence on the times and places where increases occurred. It is hard to see how industrialization could have reduced exposure to pathogens.
Growing population congestion, migration, and trade associated with the process were likely to have spread communicable diseases. If correct, one must look to other factors,such as the retreat of the Little Ice Age that could have contributed to higher yields in agriculture. There were also other sources of improving productivity in agriculture that began in the eighteenth century, such as new crops for forage and food, new crop rotations, enclosures, better drainage systems, and mechanical equipment. McKeown (1983) has been the strongest advocate for better diets in improving health in the nineteenth century, and Fogel (1985) has used data on average heights and agricultural production to buttress and quantify this point of view. Razzell (1993) and Livi-Bacci (1983) have downplayed the contribution of nutritional inputs to improving health over the long term, citing factors such as the independence of many diseases from nutrition, human adaptability to food availability, smallpox inoculation, and changing virulence of diseases.
While more research should be done, connections have been made between rising heights and improving diets in specific countries. Weir (1997) argues that growing meat consumption contributed significantly to rising heights in nineteenth-century France. Sandberg and Steckel (1980) suggest that diffusion of potatoes was important to improvements in stature in Sweden in the early nineteenth century. More generally, dietary improvement in nineteenthcentury Europe was made possible by technical improvements, such as light iron ploughs, steam threshers, mechanical harvesters, and commercial fertilizers, as well as by agrarian reforms such as enclosures or emancipation of serfs (Tracy 1964; Trow-Smith 1967; Jones 1968).
In the middle of the nineteenth century, diets also received a boost from the free trade movement. This and greater speed and lower transportation costs on long ocean voyages made it feasible to import foodstuffs from Australia and from the land-rich countries in the western hemisphere, principally the United States, Canada, and Argentina (O'Rourke and Williamson 1999). There is also evidence that public health measures, though based on an inaccurate theory of disease causation, were somewhat effective in reducing mortality rates in cities (Szreter 1988).An increase in average height may have been assisted by gains in consumption per person that followed from reductions in conflicts that absorbed resources. Although there were some revolutions and assorted small wars in Europe during the nineteenth century, the Napoleonic Wars, which ended in 1815, were the last major conflict until the First World War. Some religious strife persisted, but in fewer places and at lower levels than existed during the Reformation.
5.