In today's excerpt-as many as half of the people in classical Rome and medieval Europe did not know their age:
"The average numeracy and literacy of even rich people in the classical and medieval eras in Europe was surprisingly poor. Aurelius Isidorus, a prosperous landowner in Roman Egypt in the third century AD, gave five known age declarations. No two of the declarations are consistent. Clearly Isidorus had no clear idea of his own age. Within two years' time he gives ages that differ by eight years. Other sources show that Isidorus was illiterate.
"Isidorus's age declarations show a common pattern for those who are 'innumerate.' That is a tendency to round the age to one ending in a 0 or a 5. In populations in which ages are recorded accurately, 20 percent of the recorded ages will end in 5 or 0. We can thus construct a score variable H-which measures the degree of "age heaping," where H = 5/4(X-20), and X is the percentage of age declarations ending in 5 or 0-to measure the percentage of the population whose real age is unknown. ...
"A lack of knowledge of their true age was widespread among the Roman upper classes as evidenced by age declarations made by their survivors on tombstones, which show a high degree of age heaping. Typically half had ages unknown to their survivors. Age awareness did correlate with social class. More than 80 percent of officeholders' ages were known to relatives. When we compare this with death records for modern Europe we find that by the eve of the Industrial Revolution age awareness in the general population had increased markedly. In the eighteenth century in Paris only 15 percent of the general population had unknown ages at the time of death, in Geneva 23 percent, and in Liege 26 percent.
"We can also look at the development of age awareness by examining censuses of the living. Some of the earliest of these are for medieval Italy, including the famous Florentine catasto of 1427, a wide-ranging survey of wealth for tax purposes. Even though Florence was then one of the richest cities of the world and the center of the Renaissance, 32 percent of the city's population did not know their ages. In comparison a census in 1790 of the small English town of Corfe Castle, with a mere 1,239 inhabitants, most of them laborers, shows that all but 8 percent knew their age. The poor in England around 1800 had more age awareness than office holders in the Roman Empire.
"Another feature of the Roman tombstone age declarations is that many ages were greatly overstated. We know that life expectancy in ancient Rome was perhaps as low as 20-25 at birth. Yet the tombstones record people as dying at ages as high as 120. In North Africa, 3 percent allegedly died at 100 or more. Almost all these great ages must be complete fantasy. In comparison, a set of 250 relatively prosperous testators in England circa 1600, whose ages can be established from parish records, had a highest age at death of 88. Yet the children and grandchildren who memorialized richer Romans did not detect any implausibility in recording these fabulous ages."
Gregory Clark, A Farewell to Alms: A Brief Economic History of the World, Princeton, Copyright 2007 by Princeton University Press, Loc. 3246-85