It is often stated that, in the U.S. a century ago or in many primitive societies, the life expectancy was thirty or forty years.
But such claims never say whether this includes infant mortality and death of mothers giving birth
Obviously, this makes a big difference. An infant who dies and someone who dies at eighty give an average of forty, but this is clearly misleading.
What life expectancy suggests to most people is the age to which one can be expected to live once one has reached, say, eighteen and has not succumbed to infant or childhood disease.
It’s not true that “such claims never say whether this includes infant mortality and death of mothers giving birth.” There are lots of statistics and news stories about such things, but you haven’t had a chance to read them. Here’s something to start on. As you can see, a 20-year-old white male in 1850 could expect to live for 40.1 years more, while in 2011 he could expect to live for 57.2 years more. For a 20-year-old white female, in 1850 it would be 40.2 more and in 2011 it would be 61.8 more. For a 20-year-old non-white male, in 1850 it would be 35.11 more and in 2011 it would be 53.6 more. For a 20-year-old non-white female, in 1850 it wold be 36.89 more and in 2011 it would be 59.3 more:
I don’t think that’s what “life expectancy means to most people”. What’s magic about the age of 18, such that deaths before age 18 are irrelevant to the concept of life expectancy?
When you talk about life expectancy, you have to ask “whose life expectancy?” If you’re talking about a newborn, then obviously perinatal and childhood deaths are highly relevant. If you’re talking about a twenty-year-old, then the risk of dying before age 20 is irrelevant. If you’re talking about an eighty-year-old, then the risk if dying before age 80 is irrelevant.
If people talk about life expectancy for a particular society without any express or implied qualification, they usually mean life expectancy at birth. And, even if they don’t mean that, that’s how they are likely to be understood.
Where are you seeing these statistics that don’t mention that? Every time I’ve seen statistics like that, the source has been quick to point out that the difference is mostly from infant mortality. Maximum lifespan hasn’t really changed at all, for as far back as we can determine.
I’m not sure exactly what question this thread is asking, but I would agree with the OP that most people who haven’t spent much time thinking about the subject tend to find life expectancy at birth figures misleading. I have to explain to students on a regular basis that although life expectancy in Shakespeare’s England was around 35, this does not mean that a 30-year-old person was considered old or that 40-year-olds were rare and unusual.
Yes, the maximum lifespan hasn’t really changed, but the expected additional years of life is definitely more at 10 or 20 or 30 or 40 or 50 or 60 or 70 or 80 or 90 or 100 or whatever than it was 100 or 200 or whatever years ago.
Steven Estes, I have contacted you by PM to indicate that you should reduce the number of threads you are starting every day. Since you have chosen to ignore this, I am going to start closing your threads. Please start no more than two threads a day, and wait until some of your questions have fallen off the first page before starting new threads.
It’s not just infant mortality that skewed the numbers, but childhood mortality in general. There’s some interesting notes and analysis at PATTERNS OF CHILDHOOD DEATH IN AMERICA - When Children Die - NCBI Bookshelf The most relevant being “In 1900, 30 percent of all deaths in the United States occurred in children less than 5 years of age compared to just 1.4 percent in 1999 (CDC, 1999a; NCHS, 2001a). Infant mortality dropped from approximately 100 deaths per 1,000 live births in 1915 (the first year for which data to calculate an infant mortality rate were available) to 29.2 deaths per 1,000 births in 1950 and 7.1 per 1,000 in 1999 (CDC, 1999b; NCHS, 2001a).” Basically, kids died more often due to infectious diseases and complications from injuries. Part of this was due to lack of vaccinations/antibiotics and sanitation, as well as the prevalence of child labor in agriculture and industry for somewhat older kids. That said, it seems like making it to one year old was certainly the biggest milestone, but there were still a lot of risk up until about age five. So maybe 18 is a bit high to call someone “safe,” but certainly the additional life expectancy for a two year old wouldn’t be as good as a 10 or 20 year old.
Let me clarify one thing I said above. I said that “the maximum lifespan hasn’t really changed”, but that’s not quite true. It depends on what is meant by the term “maximum lifespan”. There is no such thing as a point at which humans can’t possibly live longer. There’s no internal clock that times out at a given number of days of life. All we can talk about is the longest lived person within the time of modern record-keeping. Consider this table from Wikipedia:
Wikipedia has decided, somewhat arbitrarily, to start the period of modern record-keeping at 1955. In 1955, there was someone who died at 113 years and 65 days old. Until 1959, that was the limit, but then someone died at 113 years and 206 days old. Until 1978, that was the limit, but then someone died at 113 years and 283 days old. Until 1983, that was the limit, but then someone died at 114 years and 222 days old. Until 1985, that was the limit, but then someone died at 115 years and 79 days old. Until 1988, that was the limit, but then someone died at 122 years and 164 days old. There has been no one older since 1988, but take a look at this table:
Since 1988, although no one has passed the oldest person ever, as you can see there have been at least nine more people who have lived at least 116 years and 311 days. Each of them would be at least three years older than anyone else in 1955. So in a sense the maximum lifespan has increased. It hasn’t increased by much, but it has increased.
Yes, it’s true that the improvements made by modern medicine (and some other things) have mostly been on the health of younger people. Not all of them have been about younger people though. Yes, someone who’s 0 years old can expect to live more years than formerly. So can someone who’s 10 years old. So can someone who’s 20 or 30 or 40 or 50 or 60 or 70 or 80 or 90 or 100 or 110 years old. Improving the expected number of years to continue to live is much harder scientifically for very old people than improving the expected number of years to continue to live for very young people, but advances have been made in medical science even for things that mostly apply to the extremely old.
From what’s been presented already, going back 100 years or more, with an average life expectancy of 30-40 years, it seems like you could reasonably expect to live to about 60 if you made it to adulthood (whatever exact age that may be). So a graph of the mortality rate for a particular person would be something of an inverse bell curve. Infant and childhood diseases and complications were devastating, and the ability to treat geriatric conditions was limited.
Today, life expectancy is about 80 years right from birth. That graph would be pretty flat from the beginning (with a bit of a spike right at 0-1 years) then starting to climb around age 50-60. Most of those childhood diseases and such have been eliminated, and we’re better at treating the conditions of the aged, but there’s only so far we can go with it currently.
Here are some survival curves from modern times vs historical times.
As can be seen, in primitive societies (both pre-agriculture and post-agriculture but pre-industrial) about 30-50% of people die in childhood. But even after that, people are still dying constantly and very few are left by what we now consider middle age. Things like disease, accidents, warfare, predators, starvation, etc. kill off the adults pretty consistently. Its weird to think that in historical terms, there were societies where most adults were in their 20s and 30s. To us in modern times, people like that are essentially just kids.
I don’t have stats for these other claims, but I’ve debated them before so I’ve looked into them.
About 100 years ago, only about 60% of men who were 18 would survive to 65. In modern times it is closer to 80-90%. So even in the last century the % of men who were 18 who would make it to retirement years skyrocketed.
Around 1940, life expectancy at age 60 has grown by about 5 years for both genders. So yes a lot of the life expectancy gains have come from drops in childhood deaths.
But there are still a lot of gains compared to historical societies in life expectancy in adulthood. In the hunter gatherer tribes or Roman era, lots of people still died in their 30s and 40s. That is rare in modern society. Plus even within this century, the % of 18 y.o. men who survive to 65 or the life expectancy at 65 has gone up.
But overall, most of the gains in life expectancy are from preventing deaths from causes unrelated to old age. Disease, malnutrition, accidents, violence, etc. The life expectancy gains from delaying death from old age are probably under 5 years.
The very fact that the very oldest people cluster around the same general age when they die seems to contradict your first paragraph. Whether you want to admit it or not, it seems quite clear that, at the very least, there is a practical limit to how long it’s possible to live.
Absolutely agree. Infant mortality is virtually always mentioned. Mortality before 5 years (“early childhood mortality”) is also very brought up. One or the other anyway. Even mortality before 16 years isn’t that uncommon to see given.
The notion of a “practical limit” to how long people live has no clear definition. It’s true that there probably have been only two people to live beyond the age of 117 in all the existence of mankind (and there have been something like 108 billion people during that period). However, two people have passed that age. One very lucky person lived to 119. One incredibly lucky person lived to 122. 122 is not in any sense a limit, nor is 117. 117 is just the greatest age we can expect that anyone (other than a tiny proportion of all mankind) will live given the present state of medical science. As medical science continues to improve, more and more people will live to 117. Eventually someone will live beyond 122. Those ages will certainly (for the next few decades at least) be rare, but they won’t be quite as rare as they are now. There’s no practical limit to human ages, whatever you mean by that the term “practical limit”.
I think this point is layered in some of the earlier comments, but I wanted to pull it out. In earlier centuries there are 3 big factors that indicate broadly someone’s chances at longevity.
-Gender - Women died in childbirth (estimates range 15% or higher)
-Age - Infants died in their first year at a higher rate (12% or higher), 33% of children estimated to die before age 15
-Access to resources - medicine wasn’t what it is now, but leaving town ahead of disease, access to food (towns could turn into deathtraps)
Once you get past the age of 15, you had a decent chance of living a long life. Not 116 years, but not 40.
Longevity may have actually declined. If longevity is defined (as I do arbitrarily) as the expected age the average person would be expected to live to if not interrupted by trauma or contagious disease. I suspect that even millennia ago, a person not felled by injury or diseases very typically lived to ages comparable to today. But many, many more could not be saved from an external cause of death , which would only skew a definition of actuarial longevity.
But, that would be tempered by our modern inclination to keep babies alive until reproductive age, even if they are likely to carry genetic tendencies to die very early. So many people today inherit life-shortening genes, and we keep them alive until they can reproduce more issue with life-shortening genes.
No. I thought I already made it clear that it was based on my supposition, tendered only for the expansion of the discussion. But if true, it would be one of those things that political correctness suppresses.
Do you doubt that people inherit their longevity, including conditions that contribute to the shortness of it? What do you suppose happens to those genes, if their carriers are artificially kept alive until they reproduce?