Most of us died before the age of 30 during that period of time
When we hear about average life expectancies of the days of yore, infant mortality is almost always factored into this calculation. The truth is, if a human made it past infancy, their life expectancy approached 65+.
So, when speaking of cavemen or Ancient Egyptians or whatever, when we hear "average life expectancy of ~30", or "most of us died before 30", it's technically and semantically correct when including all those babes that died in their first year or two of life, but it's misleading and thus not very useful.
I don't know if it's historians and anthropologists trying to be cute or pedantic or what, but I wish this meme would just die, because it paints a deceptive portrait of the past.
Life expectancy has improved a lot in general, but less dramatically at old ages.
I assume this is at least partly deliberate, because it's a major part of what has been termed the "Religion of Progress," in which the history of humanity, when you squint hard enough and ignore most of the actual history, is a "rising line from the caves to the stars." Life in the past must be worse than life today in every reasonable way you can describe it, and life in the future must be better than today, because this is what's demanded by the current myths.
The problem, of course, is that any moderately in depth study of the history of humanity demonstrates that this absolutely hasn't been the case, outside the effects of the industrial revolution from the past 250 years or so - which, as is now becoming rather obvious, has some serious downsides as well as the assorted miracles it's produced. And the focus of some of the (if not brightest, at least best paid) members of society on tricking other people into staring at a bunch of tiny flickering dots for as long as they possibly (while the world is literally burning around them) can doesn't seem like the sort of thing that's going to be considered particularly well in the future. Not that we should be praising it right now.
JM Greer has done some solid writing on the "Religion of Progress" concept, and it's just depressing how often you see life and history crammed into that mold, because it's the way we've been trained to think of the world. It's also going to be responsible (or is being responsible) for a lot of mental anguish when reality refuses to deliver what we think the future ought to be. Humans won't go to the stars. We probably won't ever have flying cars, Jetsons-style. Etc.
So, my favorite distinction is between “life expectancy” (which is a misleading average that includes early mortality) and “longevity”, which is what people often really mean, the typical length of life of someone who doesn’t die early of some kind of accident or disease while young. Longevity is the word to use for living to a ripe old age and to factor out infant mortality.
If you want to be really triggered, take a look at the graph at the bottom of this article by Ray Kurzweil: https://www.kurzweilai.net/the-law-of-accelerating-returns
That is so wrong and so completely and intentionally misleading (note how it leaves out known data points from the mid 1900s and from before 1850, and how the article is intentionally conflating longevity and life expectancy) that it has convinced me that Kurzweil is a charlatan and I can’t trust a single thing he’s written. It’s a bummer because I really enjoyed his keynote on double exponential growth and eventual immortality at Siggraph one year. Fun ideas but now I see he and the other eternal life pseudo scientists are selling snake oil.
>Based on the data from modern hunter-gatherer populations, it is estimated that at 15, life expectancy was an additional 39 years (total 54), with a 60% probability of reaching 15.
Soot and smoke was one of many hazards.