Possible factors in the health decline

A cooling trend began around 1200 and by the fourteenth century, weather related events began to cause havoc in northern Europe (Fagan 2000). By the late fourteenth century, the Vikings had abandoned Greenland and in the next century, England no longer cultivated wine.

Important for agricultural production and health, the climate change was irregular. Imbedded within the general cooling period of 500—600 years were numerous seesaws of 15—40 years' duration. The changing weather patterns made it difficult for individuals alive at the time to identify true long-term trends, which were noticeable only with intergenerational perspective. The lack of knowledge about actual trends postponed adaptations to the cooling climate, and during temporary reversals of cooling, encouraged investments in ways of farming and living that later proved unsuccessful.

Urbanization and growth of trade that began in the late Middle Ages gathered steam in the sixteenth and seventeenth centuries. In northern Europe, there was only one city of 100,000 or more people in 1500 (de Vries 1976). By 1600, the number of people living in such places had quadrupled, and within another century it had tripled again. As height studies for the late eighteenth and early nineteenth centuries show, large cities were particularly hazardous for health, acting as reservoirs for the spread of communicable diseases (Steckel and Floud 1997: ch.

The spread of disease that began with revival of trade and urbanization was reinforced by another source of pathogens that began in the late 1400s, and later intensified: global exploration and trade. The voyages of Columbus and Vasco da Gama were merely the first of thousands by which Europeans acquired global information that was used to build and maintain colonial empires. Within 300 years, Europeans had mapped most of the globe and established numerous colonies or trading centres on all continents or islands significant for producing saleable products. Syphilis is only one of numerous diseases that spread during this era. It is well known that the early stages of globalization began in the late 1400s and eventually led to the worldwide diffusion of many diseases into previously isolated regions or continents (Crosby 1972, 1986).

As a measure of net nutrition, average height is adept at measuring a population's consumption of basic necessities such as food, clothing, shelter, and medical care. In countries with high levels of per capita GDP, most people have enough of these to satisfy basic needs. But in poor countries or among the poor in moderate-income countries, large numbers of people are biologically stressed or deprived, which leads to stunting. In addition to income, average height is therefore sensitive to the degree of inequality (Steckel 1983, 1995). It is difficult to acquire information about income or wealth inequality in the distant past, but Hoffman et al. (2002) have been ingenious in assembling related information by using information on the prices of products heavily consumed by the rich or by the poor. In their study of price patterns for staple foods and fuels relative to the prices of luxury goods, such as servants, they find that real inequality rose considerably during the sixteenth century and remained high until the twentieth century.

Since the poor comprised a large segment of the population, it is plausible to believe that growing inequality could have increased biological stress in ways that reduced average heights in the centuries immediately following the Middle Ages.

Although state building could be credited, in many cases, with eventually improving economic efficiency, the early stages of the process also absorbed resources, cost human lives in conflict, and may have increased inequality. Someone might be able to argue that religious wars and conflicts improved health when or shortly after they occurred, but I find it difficult to imagine a mechanism. From the War of the Roses in the late fifteenth century and the Reformation in the early sixteenth century, many parts of Europe were in sporadic and sometimes protracted conflict or turmoil until the conclusion of the Napoleonic wars in 1815.

Economists and historians have long discussed Malthusian processes affecting population health and growth. Positive checks on growth, in the form of higher mortality rates created by growing pressure of population on resources, would have led likely to diminished stature. John Komlos (2000) has argued that industrialization was an adaptive response to such pressures, but presumably they existed (without or with less adaptive success) in earlier centuries. The course of population over the past millennium is reasonably well chronicled (see McEvedy and Jones 1978) and plausibly periods of rapid growth that pressed on available resources and given technologies could have been a factor in height trends. The rapid growth of population from the eleventh through the early fourteenth centuries, for example, might have been a factor contributing to height declines of the late Middle Ages.

It would be premature to attempt to identify an era that was the worst in the last millennium for European health and nutrition, but historical evidence suggests that the seventeenth century is a leading candidate (de Vries 1976). Contributors to The General Crisis of the Seventeenth Century (Parker and Smith (eds.) 1997), focus on Europe but argue that the hardship probably spread well beyond this region. During this century numerous adverse forces acted together. It was part of the coldest period of the Little Ice Age, and subsistence crises were numerous. Religious turmoil was raging as signified by the Thirty Years War, and political instability was marked by the English Civil War and by numerous peasant uprisings. Economic inequality was intense as indicated by the rise in the price of necessities relative to luxuries. Global colonization and the associated spread of diseases were in full swing, as was a rapid increase in the number of large cities. It remains, however, to connect these events to changes in average stature.

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