# What kind of effect would a long lifespan have on humanity?

Suppose that, after puberty, human beings aged about 15 times more slowly than in our world. Some would still die young (by their standards) due to diseases, wars, accidents, etc., but it would be commonplace to live to be 1000.

What kind of effect would a long lifespan (but not immortality) have on humanity? For example,

• If women didn't reach menopause until their 500s or 600s, would large families be more commonplace?
• How would the institution of monarchy (or other appointed-for-life positions, like US Supreme Court justices) be affected by having the same people in power for centuries?
• How would criminal justice be different if it were possible to actually serve a 600+ year prison sentence?
• How would historiography be different if people who lived through the Crusades, the Renaissance, or the American Revolution were still with us?
• I recommend reading Stephen Baxter's Destiny's Children books if you're interested in some exploration of this issue. The books have more themes than this, but it is one of the important themes. – Almo Oct 28 '14 at 19:11
• I like the questions you're asking here, but I wonder if having them all be in one question makes this too broad? You're asking about physical, legal, historical, and societal changes here; does it make sense to break this up? (On the other hand, there are some well-developed answers here already...) – Monica Cellio Oct 29 '14 at 1:23
• In the movie Star Trek: Insurrection, the focus was on a group of people who settled on a planet that turned out to be a fountain of youth. Might be worth watching, as it does show some of their culture. – cimmanon Oct 29 '14 at 19:56
• Since you mention Methuselah, you would want to study Genesis 1 up until 6,8. – MarnixKlooster ReinstateMonica Oct 30 '14 at 5:52
• Funnily, people were 20% smaller 2 centuries ago. Newborns would be surrounded by dwarves. :-) – Pierre Arlaud Oct 30 '14 at 9:00

Quick observations:

1. If the people from history were still around, history would move more slowly. The idea that Racism is acceptable in the Western world is decreasing/dead because younger people don't think racism is okay (brought up that way with media and legal influence to ensure it) and the people who thought racism is okay are dying out. The morals/beliefs/stigmas of the past would still be present today even more than they currently are. I don't believe that religion is BS but water nymphs and mermaids are. Likely some people who claimed to have seen them in the 1500's would still be making that claims today.
2. We would have more spread out children. We would still on average have roughly (+50 to 200% likely due to increased unnatural death rates) same number of children to maintain the population. Raising them would however take only 1.8% of our lives compared to 18% now. Our childhood would also be less large the same way. This would mean there would be about 10% the number of children in the world. This by itself is worth of a very long study. Easier to note, however, is that you will have fewer close age siblings. Unless you are twins or your parents are bad with birth control, you will not have siblings within 5 years of your current age.
3. War would be worse. The horrible effects of war including the population decrease would last for 100s of years. Grudges would last longer. America would still hate Japan and everyone would hate Germany. That was less than the equivalent of less than 10 years ago.
4. War would be less. "While I still remember the horrible things you did, I am still wounded from the last war. Our ideologies aren't really that different from the last time we fought."
5. The rate of technological increase would seem larger. This would mean that people who thought the cotton gin was innovative would be trying to learn how to use an Iphone. That would be the norm! Our greatest minds would have 100s of years more to study the universe and (assumed) the memory to support it. If anything the actual rate of technological increase would be faster. Nevertheless, this means that a large portion of the population would be left behind to only do manual labor unless continuing education becomes more significant. Expect to return to school for a decade every 100 years to stay on the cutting edge of whatever exremely nuianced area you are actually an expert in.
6. We would actually make things right! We wouldn't build houses meant to last 100 years... we would construct them of stone.
7. The Rule for Life people would actually be the people who did something. The monarchys of our world have been the children of the children of conquerors. Most monarchs, would be the son of the conqueror who fought by his side.
8. Increase unnatural death rates and death via disease would be observed for several reasons. If every time i go to the store i have some chance of dieing in an car accident, living to 1000 would give me alot more car rides. The same is true for fights with wild animals and older farmer brothers, floods, and extradimensional abductions. If we don't have kids till 200 then more people will die before having kids. More people will die of accidents and disease than old age. This also means more disabled people who survive the accidents living longer.
9. With respect to punishment, if we became able today to live to 1000, I would demand loudly and aggressively for the death sentence for any convicted murderer. Currently a life sentence costs the amount to keep them alive for roughly 60 years. Death sentence costs legal fees plus the amount of time needed for due process (say 20 years). Life sentence is more economical is most cases. If you bump that up to 500 years+ of upkeep...
• It's possible that progress would stagnate rather than go faster. A lot of progress needs new fresh minds willing to look past the old dogma before they can really move forwards. – Tim B Oct 29 '14 at 10:08
• Grudges would last longer. We currently tend not to place as much importance on things that happened before we became adults. E.g., few of the western world's population today think of the Israelis as "terrorists", but many of the actions in the fight to create the modern Israel qualify. It happened "before me", so it didn't happen. Good point. It would have an interesting effect. – user2338816 Oct 29 '14 at 11:07
• I would tend to agree with TimB. If only because the leaders (compagny directors and head scientists) would be in place for 100s of years. Another possibility is that, in researsh at least, those titles would move faster than others. Let's say that a head scientiat who can't keep up would keep his post only 300 years out of his 500 years of active life. They could then be kept for their knowledge, but less so than for their innovation. – 3C273 Oct 29 '14 at 12:47
• OP didn't specify the time period/level of technology. Without effective birth control, point #2 is going to look very different. Birth control had a massive impact on our actual world -- but would have exponentially more of an impact on this fictional world – Clyde Oct 29 '14 at 12:58
• @TimB In retrospect, you likely right. Patents would also last longer which could potentially slow down innovation (imagine if the radio were still patented). Nevertheless, I think the rate of innovation would still greatly outpace our relative to lifespan. If it take 64 years to go from NES to N64 rather than 14, we would still go from the first steam locamotive to the first iphone in one lifetime. I also consider that to be VERY pessimistic. I think I also hold more faith that experience with innovation fosters more innovation and helps formalize it among in a developed scientific mind. – kaine Oct 29 '14 at 13:01

Death by old age would be rare.

According to the CDC, the annual rate of accidental death in the presence of modern medical care is around 40 per 100,000, or about a .04% chance of dying from accidental injury in a given year. That means that even with the best medical care available, you have only a 64% chance of living out your potential 1100-year lifespan.

Now, project that back into historic times (say, the Roman Republic), with little effective medical care. The concept of a maximum lifespan would be nonexistent: you grow up, and if you avoided dying of childhood disease, you live until something (fall from a horse, disease, infected wound, etc.) "gets you". Almost nobody would die of the diseases of old age (cancer, stroke, heart failure).

The impact of this on society is hard to predict. Maybe you get a very risk-averse society where people act to minimize their chance of dying, or maybe you get a fatalistic society on the grounds that "you never know when you'll die, so live for the moment", or maybe something in between.

The other major change would be the shape of the demographic curve. In a stable society where the main cause of death is old age, you see roughly equal numbers of people in each age group, until old age kicks in and the numbers drop rapidly. On the other hand, a society where the main cause of death is chance, you get something that looks like an exponential decay curve: many (relatively) young people, and a few very, very old people.

It would certainly be an interesting place to live! I'll take each of your questions in turn.

If women didn't reach menopause until their 500s or 600s, would large families be more commonplace?

Yes, the key reason for this is because children continue to mature at the same rate. I believe parents would raise a family for twenty years or so and then settle back to being a couple. After a few decades/centuries they may decide to have another family (one or more children).

I suspect it's extremely unlikely that parents would continue to have children every 5/10/20 years, most parents today like to have their children together so they can grow up together. By having age gaps of 20 or 50 years between siblings they would lose this opportunity.

How would the institution of monarchy (or other appointed-for-life positions, like US Supreme Court justices) be affected by having the same people in power for centuries?

Appointed-for-life positions would continue to be "for life", however recently the number of for life roles have decreased. After all with people living longer they would expect to be working longer!

How would criminal justice be different if it were possible to actually serve a 600+ year prison sentence?

This is similar to above, punishments will be given as a proportion of lifespan. After all a 5 year prison term is nothing to someone who will live for a thousand years, it's a minor inconvenience and there's no real fear of the punishments.

I expect most punishments will be scaled up as a percentage. For example a 5 year term to us (assuming we live 100 years for the sake of easy maths) would last for 50 years. For more serious crimes you could be imprisoned for 600 years or indeed even longer.

Life terms of 500 years would scale too, if someone is too dangerous to be released then they wouldn't be.

How would historiography be different if people who lived through the Crusades, the Renaissance, or the American Revolution were still with us?

History would be longer!

History is divided into various types

• Living memory
• Photographed/reliably written history
• Ancient history
• Pre-history

These eras would still apply, they would simply be longer. You would be able to ask your parents about incidents in the 1600s, your grandparents about the 1200s. If you want to go back much further than this you would need to consult written records where they exist.

Other Considerations

Work and finance would be interesting, people would work for far longer and therefore accumulate more wealth over their lives however everyone would have the same amount of time to do it in. The end result of this would be the rich getting richer and the poor getting poorer (as they're on higher/lower incomes for longer). Expect a more class driven society as people get more embedded in their peer groups.

Time would generally slow down, people are raised with a set of views/values in their formative years which are very hard to shake. With longer lifespans these views would last longer. Wars, insults and discrimination would last a lot longer and (as parents have more children) are passed onto more children. Change would come, but it would be slow.

Technological advancement would depend on a number of factors. Assuming the human mind didn't slow down or suffer from the effects of old age education would be stretched out and provide far more insight. Students although physically mature would likely study for 200-300 years before starting junior roles. The experts, industry leaders would have had centuries of experience to draw upon. Depending on biology/culture/personality this could hamper advancement (we've done it this way for the last 500 years) or boost it (people know more and have a wider range of knowledge to draw upon). I wouldn't be surprised if there were more career changes throughout people's lives - would you want to work in the same industry for 500 years!?

Pets and animals would hold less importance to us, very long lived animals (such as tortoises) would be far more popular.

Investment would be made in long term solutions, that line of code you wrote which will only work for the next hundred years? You could still be working there - approaches to quality and resilience to time would be far more robust.

TLDR

In short not a lot would be different, time would simply scale up. Where things would change would be the family structure. Because people would still mature in the same timeframe I'd expect parents to have several generations of children raised together. As a result it would not be uncommon for parents to have 10-20 children over their livespan split into groups of 2-3 over their 200s-500s.

Assuming that life passes at an experientially similar rate ( so days are perceived much as we experience them ) then these long-lived folk are an interesting proposition.

With centuries to live and experience, one might expect that people would have multiple occupations over their lives- if it takes ten thousand hours to gain expertise ( not entirely accurate but a passable guideline ) then the Methuseloids have the opportunity to gain expertise in many activities over their lives- possibly even all the activities. Consequently one might expect them to be generally erudite, having had plenty of time to master many arts, crafts or skills they desired to. A Methuseloid who had dedicated themselves to a single craft over a lifetime could be expected to be one of the greatest practitioners of that craft that had ever lived.

In the long range many things that seem important to us are likely to be irrelevant to them- there would be far less need to hurry anywhere ever - but longer term concerns such as environmental change would present a direct problem to individuals rather than a generational concern, so they may be addressed more intensively.

Institutions would probably tend towards conservatism as everyone has a clear recollection of the past and experienced a long stretch of it, there would be time to experiment with different forms of government and to choose one that offered comfort and stability. Probably changes would be slower, so leaders might be chosen every twenty or fifty years- in a thousand year life, one would experience 250 american presidential terms. These people can afford to contemplate and think through decisions before they make them. This also gives interesting narrative possibilities in terms of how they might react to rapidly changing events, although they would probably have an equal amount of time to plan for contingencies so they might be notoriously well prepared.

I suspect that the idea of a monogamous marriage would be an exception rather than a rule over this type of duration- to us thirty or forty years may be a long time to be with a single partner, to them it is nothing. You might also find this was a fairly sexually liberal society - a "seen it all before" attitude might also mean that they tended to be somewhat jaded about matters of the body and relationships. The dark side of this could be a search for novelty or the risk of a descent into ennui.

Looking at human populations, long life expectancies tend to result in lower birth rates and one might expect the same here. In fact with this type of duration it might even be that to enable a shared childhood ( which would perhaps be socially beneficial ) there was some long fertility cycle of - say - fifty years or a century, where the Methuseloids are able to give birth and they are otherwise infertile.

In terms of justice, imprisonment seems improbable. Given the long duration of life and the limited population, it is more likely that exclusion or banishment would be a punishment for smaller crimes, perhaps for a few decades or centuries. Execution might also be held in place for more serious transgressions.

They may not keep pets unless they could find ones that were very long lived.

Death is the great equalizer. With death so rare, unequality in the world would increase dramatically.

People in power would have lot of time to establish legacy for their own children, and they will have very few children. People out of power might have more children - close relatives would be like a tribe, and a tribe with many members would be the only way to oppose people in power.

Those in power would feel few restriction to exterminate huge amount of their enemies "working bees", because they know that in few decades they can breed the population back. This new population will be properly scared and obedient.

Democracy would be impossible, because it would be against the interest of powerful few, and they will have lots of time to establish caste society. And in democracy, it would be possible for dedicated subgroup to 'outbreed' subgroup with different religious principals, so again it would not work. Google "full quiver", it is happening even now.

Technological progress would be much slower, because it requires new generation to accept new ideas - and new generations would be much rarer. And for growing-up person, the indoctrination period (when s/he is expected to listen up and follow orders of elders/authority) would be substantially longer, again slowing progress.

Population growth would increase (many women would have different child with different man every few years - they do even now) and so also environmental pressures of the living population on available resources. Possibly most common cause of death would be death as result of war operations. Genocide would be more common, to make sure to get rid of competing population. And likely more acceptable.

Is more risk for a woman to have child - so powerful would have polygamy to create tribes of kin. To denying chance to breed a tribe of own kin to other men, castration would be common, especially as punishment to oppose authority.

This will lead to very strict caste system and strict paternalistic society.

Low worker caste would be bred for low intelligence and obedience. Another caste of warriors would be bred for obedience and bravery. Whole military units would be from close kins, increasing unit cohesion (and potential chance of revolt), so disobedience will be punished in extreme brutal ways (eliminating hundreds of close relatives of any traitor warrior).

Arts and crafts would mostly ignored, because most important skill would be plotting your way to the top of the pyramid of power and accounting for centuries old grudges which influence other players (and teaching your own kin about those old grudges, which will reinforce them).

• I like a lot of this but I'm not sure I agree with your views on war... I don't know how you explain that a long lived race would value life less? – Liath Oct 29 '14 at 11:31
• @Liath If you have overpopulation, war is alot more likely. This is because many people are fighting for limited resources/power/land. This is a very pessemistic answer while mine is optimistic. I assumed people would not have "a different child...every few years" but if they did, many more people would die from war than in our world. – kaine Oct 29 '14 at 13:22
• Democracy is not a factor of wealth distribution, it is a factor of the distribution of military power within a society. Athens, Rome, the Swiss Cantons, Dutch Republic, England etc all were forced into Democracy by the need to marshal a large percentage of the population for military service. – TechZen Oct 29 '14 at 15:35

The top-voted answers are great and cover many aspects of what is possible if this is the reality.

However, I'm surprised nobody has mentioned population control yet. Assuming that this world is still living in the same Earth we are living in now, it would be a problem if the life expectancy grew by 1000% or so, but the rate at which we are able to produce new offspring would still be the same.

# Science and Engineering

Since the need for more housing will increase, the rate at which research on other forms of housing (aquatic?) would hasten. We can no longer rely on just land if our population would multiply tenfold (since people die slower).

Researches and studies on sustainable living would also be prioritized.

# Law

I would expect that governments would use their power to control this, and might have a maximum child count per partner. 2 children per 100 years? The law has to take the issue of population control in its own hands if everyone wishes to make the Earth a livable place.

Earth’s 29.6 billion acres of biologically productive land and water could sustainably support only about 1.5 billion people at an 'American standard of living and consumption.'

• Population control doesn't have to involve children in any way; if some fictional place has an overpopulation problem, then increasing deaths works as well (or better/faster) as reducing births. Obvious solutions would involve sending people off to slaughter your neighbours and take their scarce resources (such as housing, as you say) and die in the process, or a liberal application of death penalty for thinking in ways not liked by your 1000-year-old monarch. – Peteris Oct 29 '14 at 11:30
• @Peteris I agree, however, in a humane society like ours (assuming their culture is more or less similar with us), it is much easier to control the number of births rather than increase deaths. Imagine the number of protests regarding unnecessary killing. Haha. But then again, the same goes for controlling birth coughreligiouspeoplecough – Zaenille Oct 29 '14 at 15:55
• Actually, it is very difficult to control the number of births. First, it can't happen at all before effective contraception unless you're willing to slaughter infants en masse - so the formation of all the traditions, culture and religion would involve population control w/o contraception - either no population control (the natural pressures will lead to a 'balance' by increasing deaths) or deliberate control by killing. – Peteris Oct 29 '14 at 16:51
• Second, even in modern times it's very difficult to enforce population control against the will of the individuals and their natural instincts. It requires the efforts of a strong centralized state with strong control of it's citizens, and it can't be democratic. Furthermore, as in classic 'tragedy of the commons' scenario, the desired solution for each country is to breed as much as you can but have everyone else restrict births - noone wants to be the first or the only place to start doing so, become weaker compared to neighbours and risk becoming 'Lebensraum' for their overpopulation. – Peteris Oct 29 '14 at 16:55
• Overpopulation is a myth. Humans have controlled their population since hunter-gatherer times. Apparent harms of overpopulation in the modern world, like famines, are all linked to state policies that cripple food production. Overpopulation is an elitist and often racist concept, a rebranded from of cute and fuzzy "white man's" burden that give white first world's the pretext to manipulate the lives of non-whites in the 3rd world. Had we acted in the 70s as urged by advocates link Paul Erlich, we would have murdered at least tens of millions needlessly. – TechZen Oct 30 '14 at 1:54

I go back and forth, I think having long life expectancy would make people more like Tolkien elves, then I think about if everyone was rich, no one would be rich. Meaning if everyone could expect to live on average 700 years, it might not be terribly different than now.

Things that would make a difference, having a 5-600 year fertility period for women would likely mean no reason to have more than one at a time at home, maybe have one every 50 years or so, make sure each one has a good strong start in life.

Homes would likely to be very different, the average home in the US I think is expected to last about 100 years. So having to rebuild your home 5-8 times over your life could be problematic. Likely stone, brick, and steel will be much more common for structures.

That is also a very long time to 'collect' junk.

Having a life expectancy that much longer would also slow down changes by evolution, likely having about 1/5 - 1/10 the number of generations over the same time period.

That is also a very long time to remember things, so either larger brains would need to be grown, or very large parts of ones life would just be forgotten.

• It is not about everybody would live to 1000 years. It is about me and my kin live long - and we need resources of YOUR tribe to do that. – Peter M. - stands for Monica Oct 29 '14 at 14:50
• @PeterMasiar Um, I'm not sure what you are getting at. – bowlturner Oct 29 '14 at 14:56

Birth control is going to be a major event in the history of this world.

I don't have any hard numbers on the mortality rate of pregnancy in pre-modern times, or how different that rate might be between, let's say medieval europe and china, but I suspect it's not good.

Now multiply that over a lifetime with 50 pregnancies, or a 100 pregnancies, or maybe even 200 -- a woman is overwhelmingly likely to die from pregnancy complications or childbirth at some point.

Now maybe social norms and behavior would change in accomodation for this -- maybe less frequent intercourse or something like that. But that didn't happen in our actual world and pregnancy was pretty risky even for us.

Another point to consider is what else about our physiology would have to be different in order for long life spans to evolve. In the real world, there's no selection pressure for longer life once you've lived long enough to push out a few offspring. So maybe people are much less fertile in this world? You've ruled out a longer development time for juveniles.

• Humans live roughly twice as long as other mammals of the same body mass. We're curve busters in that regard. Likely, we did face selection pressure for long life owing to the human need to preserve knowledge in human brains before literacy. – TechZen Oct 30 '14 at 1:45

This went way long but I have some apparently counter intuitive conclusions so I fleshed them out. At the top is the summery and and answers to specific question of the OP. Below are detailed arguments if you wish to read them. (Anyone who does so gets a cookie.)

My core conclusions are:

• Methuselah's would have a society based on flexibility, adaptability and change.
• Methuselahs would develop technology more quickly.
• Methuselahs would have a less hierarchal more egalitarian and merit driven society.
• The idea that youth promotes change and adoption of good new ideas is not historically supported. A society of Methuselahs would be not be inherently more static.
• Societies don't change because old people die, they change to adapt.
• Elites cannot control society to prevent change.

If women didn't reach menopause until their 500s or 600s, would large families be more commonplace?

Simply having one woman fertile over a few centuries instead of a series of women over the same span, would not change the overall birthrate. Humans have regulated birth rates since hunter-gatherer times. People have the children they can support in a given environment with the already extant population. That would be true regardless of how long we lived.

A long lived species of humans would not have much turn over so they would have to limit replacement births. Their populations growth in absolute size would mirror our own, expanding gradually up during the agricultural era when children are important for labor, then a slight uptick at the beginning of industrialization, then a sharp drop off as children began to absorb more resources.

How would the institution of monarchy (or other appointed-for-life positions, like US Supreme Court justices) be affected by having the same people in power for centuries?

Not much. The practice is largely followed in countries that still have substantial adherence to common law i.e. historical defined law. Judge's power was checked by the precedents set by previous generations so no other mechanism was needed. The major function of life time appointments was to limit the power of outside actors to influence judges, by influencing their reappointment. That dynamic would not disappear.

If people pursued multiple careers in their lives, they would likely switch to a system we use with US Presidents, a fixed term coupled with an ban against serving again. So, you could be a judge for 50-100 years but then you'd be out of judiciary forever. Judges would be independent while sitting and then have to switch careers.

How would criminal justice be different if it were possible to actually serve a 600+ year prison sentence?

Bizarrely long but fixed prison sentences are the result of the very strange accounting system used in the criminal justice system. It got really baroque in the 1960s. They are intended to serve as life sentences for accumulations of crimes that individually, for whatever reason, cannot individually warrant a life sentence. Not all societies use them and they used to be rare in American.

The prison is only partially deterrence from loss of freedom. The experience of the last 40 years has shown that the primary good performed by prison lays in simply isolating transgressive individuals from the general populations. That need wouldn't go away in a society of Methuselahs.

If I had to guess, I would say that the Methuselah's awareness of change (see below) would likely lead them to promote capital punishment as a means of avoiding shifting conditions or chance from freeing a dangerous individual centuries down the road.

That happened for real in the 1960s when radical and unanticipated shifts in culture, law and criminal justice theories released large numbers of people who had years or decades before been sentenced life or even death. In some case, individuals sentenced originally to death either killed again in prison or were freed by corruption or accident e.g. Kenneth McDuff, and went on to kill again.

After a few centuries of experience, such an outcome would likely seem more likely than not so executions would seem a more certain form of both justice and prevention.

How would historiography be different if people who lived through the Crusades, the Renaissance, or the American Revolution were still with us?

I think the biggest change would be the ability to think of or ask question not on anyone's radar at the time. For example, prior to the 1600s, technology was almost entirely undocumented because no one of the age thought it particularly important. Most of what was documented concerned weapons. We detailed plans and models of on warships from the 1600s but rely on archeology to tell us about merchant ship construction as late as late 1700s.

While providing insight, long lives could also make historical studies more difficult.

Firstly, we have trouble discussing "living history". If the actors of events are still around, especially, if they are still prominent, things get hairy. I spent a big chunk of my life watchings Baby Boomers bob and weave around the Vietnam war even after the end of the Cold War.

Secondly, lot of recollection would be fouled by hindsight bias. Nobody is right all the time or even most of the time. When you read great works of philosophy and science from the past, what you see is 90% flat wrong with a few perils of pretty-close. On social and political matters, everybody would be seriously wrong to point of disgust about something e.g.Lincoln would be considered a hard core racist by contemporary standards.

People writing about their conduct in the distant past would constantly try to reinterpret their actions in modern terms e.g. I'm old enough to remember when leftist declared the idea that being gay was somehow physiological intrinsic was impossible and fascistic and who mocked the the idea that gay people would ever get to marry as right wing hysterical fear mongering. You won't find any advocates for gay rights from the 60s-late 80s, owning up to those then universal stances anywhere today.

Thirdly, people write contemporary they expect to be read in their lives differently than they write accounts they expect to surface only after they are gone. Diaries are different than newspaper editorials. People who lived centuries would likely write with biases assuming that they would be around when all their writing became public.

## Details

Methuselah's would have a society based on flexibility, adaptability and change.

Each individual would experience and remember more change and thus be more aware of the need for individuals and societies to be willing to change and adapt.

If nothing else, their view of the natural world would be one of extremely fast and constant change. River courses would whip about like snakes. The sea would visibly eat into the land. Mighty oaks would grow and die like shrubs. They could breed plants and animals over centuries or even millennia which would make life itself seem plastic and shifting. (Someone 500 years old today would remember when most fruits, vegetables, strains of grains breeds of dogs, cattle, sheep and horses etc did not exist.)Every middle-age adult would remember large numbers of superstorms, earthquakes, volcanos, plagues etc.

The cyclic motions of astronomical objects would be readily apparent, as would the cyclic decadal shifts in climate that occur in every region of the earth.

Natural resource bases like game lands, potable water,arable lands, navigable water ways or veins of ore would seem constantly shifting and ephemeral. Likely, they would never develop the concept of a "natural" resource at all since every individual would see many changes in how resources came into being from human effort and how resource use shifted and changed constantly.

In human interaction, they would see more examples of fluke and chance, more lost horseshoe nails loosing battles for example, and would be less likely to see current social structure as something fixed and eternal.

Certainly, the rise of literacy and historical research of all kinds has given us today long artificial memories and made us more aware of the constancy of change and our need to always adapt. Imagine how much more we'd believe this if we personally remembered those changes.

Methuselahs would develop technology more quickly.

Longer memories of individuals would mean greater and faster accumulation of knowledge in pre-literacy times. Until well after the 1600s most technological knowledge was passed directly person to person. A break in the chain caused the loss of the knowledge. People with 1,000 year old memories would not have that loss.

Long life means lots of time to learn new skills explore many avenues of thought. Each individual would have a wide range of skills of all kinds which they could bring to bear on science and invention.

There awareness of the need to change and adapt would create a powerful incentive to look for more new technologies and adapt them.

Methuselahs would have a less hierarchal more egalitarian and merit driven society.

Thinking long term, and much aware of change and chance, when on top, they would value the potential for long term cooperation centuries hence from those currently on bottom when the shoe might well be on the other foot.

Just like the rise of long distance sea trade cause people to worry more about a captain's seamanship than who his daddy was, long term planning for inevtiable change would make them value skill and merit more than the alliance du jure.

More time to learn skills would mean more time to acquire military skills which would make it more difficult for a minority warrior elite, trained since birth, to dominate a large population of craftsmen and farmers. In all known human societies, greater equality of military skill and service has lead to greater social equality while greater inequality leads to the opposite.

The inability to block individuals from rising on merit by force would also contribute positively.

With each individual having the time to learn many skills, society would be less interdependent and more robust against of disorder and disruption. In a pinch, you do without a blacksmith because everyone would know a little blacksmithing. As such, political changes and fragmentations would not present as much as problem as in societies with a high degree of specialization of labor, and a high degree of interdependence.

The idea that youth promotes change and adoption of good new ideas is not historically supported. So, a society of Methuselahs would be not be inherently more static.

Historically, it has no basis. Most science and technology development is done by people 25-35. Most business innovation by people 30-50, and most political innovation by people 45-60. E.g. the Civil Rights movement was carried out by the Greatest Generation and the Great Depression generation who where in their late 40s to early 60s in the 1960s, not the then snot nosed Baby boomers.

Basically, all the heavy lifting or organizing and getting things don is done by people around 50. People who are older wear out and can't keep up more than growing mentally inflexible.

Societies change when their internal or external environments change and they must adapt. When that happens, those with the most existing power and skill implement most of the changes.

Young people play the same role in significant and enduring political and social change as they do in wars i.e. foot soldiers.

To the extent that youth does promote change, its often random as to whether it turns out good or bad. Fascism and Communism were considered youth movements in their heyday of the 20s and 30s. Older people are much better at filtering bad ideas, the majority, and focusing on those that will produce lasting improvements. The effect is even more profound because important changes tend to be rather boring at the time and only people with discipline, experience and an eye for detail can carry them out.

Having longer lifespans would improve this skill as well as reinforcing the need to change and adapt, a relativel lack of young people would have little effect.

** Societies don't change because old people die, they change to adapt.**

By our standards, most historical societies had a higher ratio of young to old yet they remained static for far longer. If young people drove change and old ideas died because the people who held them die off, societies with higher death rates at younger ages should change faster. They didn't and don't.

Every core change in every society occurred because older, wealthier and more powerful changed their behaviors even if they didn't change their stated ideals. From religious reformation to political "revolutions" (really lateral shifts) to Civil Rights, the people that had to change to make the change stick were older, more experience, skilled, and overall effective people i.e. the people who get most of everything important either done or coordinate getting it done.

Methuselahs would be no different. Their long lives would see many changes in nature, technology and society. If they keep trying to act like it was 1300 in Germany the medieval warming period 1777 Massachusetts during the little ice age, they wouldn't last long.

** Elites cannot control society to prevent change.**

Another myth, largely perpetuated by those trying to explain why their particular really, really great and obviously true and perfect idea didn't succeed in radically restructuring society in a weekend.

Far from being inerrant puppet masters or engineers arbitrarily structuring society to their own benefit or whim, elites are historically dullards constantly blindsided by change. This happens because changes usually start small and by the time they appear to be of consequence, it's to late. Social and political change usually occurring owing to changes in the environment or in technology, neither of which elites control.

This is particularly true in the case of technology. New technologies start out about as distinctive as individual tadpoles. Only in hindsight is their rise obvious. Nobody has ever succeeded in suppressing a useful technology despite the fact that every single new technology ever, has threatened some established interest.

So, not only would Methuselahs be more positive towards change, have an less elitist dominated society, they wouldn't be able to stop change even if they wanted to.

Methuselahs probably would have hit the industrial age within a few thousands of years after the end of the last ice age, say around BCE 5000. At our stage of development, they'd probably be planning on nipping on sublight starships. What's a five hundred year stellar voyage to someone who will live to be 1,000?

• Counterintuitive, but most of it seems true, so +1. Where I see a potential weak point is that experienced people are better at avoiding problems, so there would be much less stress on the society and so much less reasons to adapt. This would accelerate some changes (we have copper for only 200 years => let's develop iron metallurgy), but slow others (most social tenses would never grow enough to cause revolutions, because we are all sensible people and mitigating the drawbacks of our government system for thousands of years is possible and safer than any revolution). – Pavel V. Dec 9 '14 at 10:42

The main cause by which History advances is that people keeping old ideas alive die. If the tribe has a hunter that keeps hunting mammoths (or elephants) for 1000 years, you can not expect that very person to lead the tribe to technological progress.

We will simply still be at stone age. New inventions would have been forbidden, since them make the bosses unease.

• Ummm, no. The mean age of people in society has been rising since the start of civilization and has accelerated in the last 200 years and change has accelerated, not slowed. The idea that people at some age freeze solid mentally and stay that way is just the fantasy of people marketing flattery to young people. People change and adapt constantly, not just as children. Your mammoth hunter would change, when he ran out of mammoths if at no other time. – TechZen Oct 30 '14 at 1:43
• @TechZen I do not agree. Just check how technological advances are produced almost always by young people (as opposed to basic science advances), and how resistent our gransparents (most of them, there are exceptions) are to innovations. Gay marriage? Smartphones? Abortion? Just make a survey in any retirement castle and see how different their POV is from the same in a High School. – Envite Oct 30 '14 at 9:31