Life Expectancy Vs. Life Span
Life expectancy is often confused with life span to the point that they are nearly synonyms; when people hear 'life expectancy was 35 years' they often interpret this as meaning that people of that time or place had short life spans. One such example can be seen in the In Search of... episode "The Man Who Would Not Die" (About Count of St. Germain) where it is stated "Evidence recently discovered in the British Museum indicates that St. Germain may have well been the long lost third son of Rákóczi born in Transylvania in 1694. If he died in Germany in 1784, he lived 90 years. The average life expectancy in the 18th century was 35 years. Fifty was a ripe old age. Ninety... was forever."
This ignores the fact that the life expectancy generally quoted is the at birth number which is an average that includes all the babies that die before their first year of life as well as people that die from disease and war. The genetics of humans and rate of aging were no different in preindustrial societies than today, but people frequently died young because of untreatable diseases, accidents, and malnutrition. Many women did not survive childbirth, and individuals who reached old age were likely to succumb quickly to health problems.
It can be argued that it is better to compare life expectancies of the period after adulthood to get a better handle on life span. Even during childhood, life expectancy can take a huge jump as seen in the Roman Life Expectancy table at the University of Texas where at birth the life expectancy was 25 but at the age of 5 it jumped to 48. Studies like Plymouth Plantation; "Dead at Forty" and Life Expectancy by Age, 1850–2004 similarly show a dramatic increase in life expectancy once adulthood was reached.
Read more about this topic: Life Expectancy
Famous quotes containing the words life span, life, expectancy and/or span:
“I’ve seen things you people wouldn’t believe. Attack ships on fire off the shoulder of Orion. I watched seabeams glitter in the dark near the Tennhauser Gate. All those moments will be lost in time like tears in rain. Time to die.”
—David Webb Peoples, U.S. screenwriter, and Ridley Scott. Roy Batty, Blade Runner, final words before dying—as an android he had a built-in life span that expired (1982)
“Worst, when this sensualism intrudes into the education of young women, and withers the hope and affection of human nature, by teaching that marriage signifies nothing but a housewife’s thrift, and that woman’s life has no other aim.”
—Ralph Waldo Emerson (1803–1882)
“O, what a noble mind is here o’erthrown!
The courtier’s, soldier’s, scholar’s,eye, tongue, sword,
Th’ expectancy and rose of the fair state,
The glass of fashion and the mold of form,
Th’ observed of all observers, quite, quite down!”
—William Shakespeare (1564–1616)
“... we’ve allowed a youth-centered culture to leave us so estranged from our future selves that, when asked about the years beyond fifty, sixty, or seventy—all part of the average human life span providing we can escape hunger, violence, and other epidemics—many people can see only a blank screen, or one on which they project fear of disease and democracy.”
—Gloria Steinem (b. 1934)