In 1858, a British epidemiologist named William Farr set out to study what he called the “conjugal condition” of the people of France. He divided the adult population into three distinct categories: the “married,” consisting of husbands and wives; the “celibate,” defined as the bachelors and spinsters who had never married; and finally the “widowed,” those who had experienced the death of a spouse. Using birth, death and marriage records, Farr analyzed the relative mortality rates of the three groups at various ages. The work, a groundbreaking study that helped establish the field of medical statistics, showed that the unmarried died from disease “in undue proportion” to their married counterparts. And the widowed, Farr found, fared worst of all.