Isidore of Seville wrote in the seventh century that “there are six stages in a lifetime: infancy, childhood, adolescence, youth, maturity, and old age.” He defined old age as beginning at 70.
In the thirteenth century, Phillipe de Novare wrote The Four Ages of Men, in which he chose old age as sixty. He subdivided old age into two stages, senectus (Latin for old), elderly but still active, and senium (senile), refers to the final stage of the human lifespan, specifically associated with the physical and mental declines of old age .
In our society, old people are spoken of as seniors. Seniors can be someone fifty-five plus, 60, or 65, depending on who makes the decision to put people into categories. And then, there is the unkind definition of old people as “units,’ enshrined into the Affordable Care Act.
If you are sixty-five or older, you are in the eighteen percent population group in America today. People live longer due to better medical care, better food, better housing, vitamins, medicines, vaccines, better education, more schooling, and overall information which humans across the centuries have lacked. Some live longer thanks to genetics and having children with a person who also has a healthier genetic code. Other groups interbreed which causes their heirs to have severe health issues which shortens their lifespan with or without proper medical care.
Most people believe that life expectancy before modern medicine was quite low for everybody, yet there are records of many people who lived to a ripe old age.
It is true that a lot of women died giving birth and many children did not live past a certain age due to unsanitary conditions, lack of proper nutrition, healthy food, water, and good shelters. Thirty to fifty percent of all births ended in the death of the newborn. Mothers and their newborn often died during birth or shortly after. If babies survived infancy and turned seven, their odds of survival increased considerably.