Why We Live 40 Years Longer Today Than We Did in 1880

Infant mortality plays a huge role. It has dropped significantly in the past century.[1]

"It is true that life expectancy in the Middle Ages and earlier was low; however, one should not infer that people usually died around the age of 30. In fact, the low life expectancy is an average very strongly influenced by high infant mortality, and the life expectancy of people who lived to adulthood was much higher. A 21-year-old man in medieval England, for example, could by one estimate expect to live to the age of 64" [2]

[1] http://www.hrsa.gov/healthit/images/mchb_infantmortality_pub... [PDF]

[2] http://en.wikipedia.org/wiki/List_of_common_misconceptions