It is not uncommon to hear talk about how lucky we are to live in this age of scientific and medical advancement where antibiotics and vaccinations keep us living longer, while our poor ancient ancestors were lucky to live past the age of 35. Well, this is not quite true. At best, it (a) oversimplifies a complex issue, and at worst, it is an obvious misrepresentation of statistics. Did ancient humans really just drop dead as they were entering their prime, or did some live long enough to see a wrinkle on their face? It would appear that as time went on, conditions (b) improved and so did the length of people’s lives. But it is not so simple.
What is commonly known as “average life expectancy” is technically “life expectancy at birth.” But life expectancy at birth is an (c) unhelpful statistic if the goal is to compare the health and longevity of adults. That is because a major determinant of life expectancy at birth is the child mortality rate which, in our ancient past, was extremely high, and this skews the life expectancy rate dramatically (d) upward. If we look again at the estimated maximum life expectancy for prehistoric humans, which is 35 years, we can see that this does not mean that the average person living at this time died at the age of 35. Rather, it means that for every child that died in (e) infancy, another person might have lived to be 70. The life expectancy statistic is, therefore, a deeply flawed way to think about the quality of life of our ancient ancestors.
* skew: 왜곡하다