A View of Early Modern Trends in Longevity Derived from Data on European Scholars

Upward trends in longevity started as least as early as the 16th century in some parts of the world, and earlier elsewhere. In England, it is thought that an intertwined slow growth in life expectancy and economic productivity over hundreds of years laid the foundations for the Industrial Revolution. People who expect to live longer are better stewards of long-term capital investment, and even small gains year over year compound over time to become large. Greater wealth in turn gives rise to the byproduct of technological progress, including that relating to medicine and public health. This results in a virtuous cycle of accelerating gains in wealth, health, technological prowess, and longevity.

Today's research materials are a novel view of the earlier trends in life expectancy over the last few hundred years, based on data for European scholars. One interesting observation is that groups of higher socioeconomic status exhibited the slow historical gains in life expectancy earlier than was the case for the broader population. Control of infectious disease has been a major driver of improved life expectancy. Prior to the advent of 20th century medical technologies such as antibiotics, that control largely involved public health measures such as improved sanitation, as well as personal health measures deriving from cultural practices. We might argue that the deployment and adoption of these measures was uneven, explaining the observed data. That medical scholars exhibited a shorter life expectancy than scholars of other disciplines, at least until the development of germ theory, might also reflect the importance of infectious disease on early trends in human longevity.

Leaders and Laggards in Life Expectancy Among European Scholars From the Sixteenth to the Early Twentieth Century

In this article, we focus on the European scientific elite: scholars active at universities or academies of sciences. Observing each scholar's first appointment or nomination to a scientific institution helps to overcome common methodological issues in historical populations given that the appointment can be used to define the entry into the population at risk. More importantly, taking into account each scholar's scientific field and potential membership in an academy of sciences provides new insights into the role of medicine and social status in the process of mortality improvements. Finally, in a world where face-to-face communication was essential for both knowledge transmission and enhancement, the length of productive life among the elite was an important determinant of the extent to which members of the elite were able to influence their cultural and economic environments.

Drawing on local evidence and data on specific social groups, historians and demographers have already shown that mortality gains were made in the seventeenth and eighteenth centuries. Longevity started rising as early as 1400 and continued to increase over the fifteenth century. However, this first phase has been observed in Ireland and the United Kingdom only and these findings are subject to considerable uncertainty. Even though the total sample size is large, when stretched over several centuries, the uncertainty regarding any specific time point becomes large. This phase of longevity improvements was followed by another after 1650 that has been observed throughout Europe in other studies as well. Building a database drawn from the Index Bio-bibliographicus Notorum Hominum, which contains entries on famous people from about 3,000 dictionaries and encyclopedias, researchers found no trend in adult longevity among individuals born before the second half of the seventeenth century. Their findings also suggest that permanent improvements in longevity preceded the Industrial Revolution by at least a century. The longevity of famous people increased steadily starting with the generations born in the 1640-1649 period and grew by a total of roughly nine years in the following two centuries.

Although these studies are important, they are not without weaknesses. In the populations they studied, who belonged to the sample and when people entered the population at risk could not be precisely defined. Some of the individuals in these populations, such as famous martyrs, might have entered at death; others, such as artists, may have entered post mortem; and still others, such as members of royal families, entered at birth. In this study, we present data that overcome such weaknesses and use these data to reanalyze the timing of mortality improvements among the European elite. Furthermore, using information about relative status within the elite, we investigate whether differences in socioeconomic position were already influencing mortality when secular changes in mortality first started, or whether this pattern is more recent. Finally, we exploit information about the scientific fields in which the scholars in our database were working to examine whether there were leaders or laggards by discipline. A particular focus of our analysis is on medicine, which may have had both positive and negative effects on longevity, depending on whether the benefits of medical knowledge offset the added hazards resulting from exposure to pathogens.

We build a large, new data set with more than 30,000 scholars covering the sixteenth to the early twentieth century to analyze the timing of the mortality decline and the heterogeneity in life expectancy gains among scholars in the Holy Roman Empire. The large sample size, well-defined entry into the risk group, and heterogeneity in social status are among the key advantages of the new database. After recovering from a severe mortality crisis in the seventeenth century, life expectancy among scholars started to increase as early as in the eighteenth century, well before the Industrial Revolution. Our finding that members of scientific academies - an elite group among scholars - were the first to experience mortality improvements suggests that 300 years ago, individuals with higher social status already enjoyed lower mortality. We also show, however, that the onset of mortality improvements among scholars in medicine was delayed, possibly because these scholars were exposed to pathogens and did not have germ theory knowledge that might have protected them. The disadvantage among medical professionals decreased toward the end of the nineteenth century. Our results provide a new perspective on the historical timing of mortality improvements, and the database accompanying our study facilitates replication and extensions.

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