You're currently dying of the "being human" cancer. Are you working on or donating to anti-aging research, or do you prefer to do other things with your time? It just comes down to your discount factor. Based on inflation, it's typically about 0.95/year, so you would expect to care about ~10% as much for things 50 years in the future. This means if you had a ~10% better quality of life not working on anti-aging, you're guaranteed to be better off. In reality, you should hedge your bets; if everyone spent just a little time on the disease, we could cure "being human". The same applies to dying fighting cancer. You should be willing to do some experimental procedures, but not if it eliminates your happiness for the rest of your life.
One assumption people making such arguments implicitly assume is that such things are possible, which is not a given. It could well be that you could have infinite money, a billion scientists, and make no progress whatsoever. And I'm only referring to cancer there. Anti-aging seems even less likely.
I think there's a lot of cognitive dissonance on this topic from people like Ray Kurzweil. The overwhelming majority of increases in life expectancy over the past millennia have come from reductions in childhood mortality. It's not like people in the past just hit 40 years old and randomly keeled over. But rather people were quite unlikely to make it out of childhood. If one person dies in childhood and the other at 80, you have a life expectancy of 40 years old but it's rather misleading! In reality the average life expectancy (for those that made it out of childhood) has remained pretty similar for millennia - around 70 years. [1]
So for instance the Founding Fathers died at an average age of 72. John Adams lived to 90, and Sam Adams/Jay/Franklin/Madison died in their 80s. The only two who died before their 60s were Hamilton, who was killed in a duel, and Hancock, who'd had poor health throughout most of his life. This is a nice sample because you had Founding Fathers as young as 18 (Monroe) when the Declaration of Independence was signed, so we're certainly not seeing a surviorship bias. They were certainly wealthier than average, but all the wealth in the world doesn't matter when state of the art healthcare was doing things like treating infections by bloodletting (including by leeches) to get rid of 'bad blood' or 'balance the 4 humors.'
I seem to be much more confident that technology could solve the aging problem. Two routes come to mind:
1. We can already splice up DNA with decent accuracy, so it's just a matter of finding what DNA to splice in/out to have the desired effects, and then a method to apply this to every cell.
2. We're close to being able to disassemble someone's nerves and simulate them with a very high accuracy. So, at the very least we could give people new robot bodies.
Now, it's true that even the wealthiest people in the world several hundred years ago had no hope to get either of these done. But it seems entirely plausible that if everyone came together to work on this now, it could be solved in a few decades. I think it isn't happening because (1) people's discount factors aren't high enough to throw everything to their future; (2) the wealthiest people are older, and have the least chance of success; (3) it's a coordination problem that most people aren't even aware they can coordinate on; (4) a significant number of people don't even think it's a problem (because of the stories their ancestors told about death maybe not being the end). The last two are solvable, but the first are just mismatched preferences that you can't really get around.
I'm rather late here so I'll keep this short since I'm probably just talking to myself, but hey it's fun to organize one's thoughts anyhow. I could argue that CRISPR is more like a chainsaw than a scalpel, but I think things like this are tangential.
In general a lot of the research around aging is more motivated by a desired outcome than a the evidence in question. Telomeres, for instance, are clearly correlational rather than causal with contrary evidence in numerous species such as mice most obviously. In general there seems to be practically a rule that any observation of biological immortality is later met with a refutation. For instance lobsters are observed to eventually stop even trying to moult as they age, which inevitably leads to their death. Senescence manifesting differently in different species obviously does not imply immortality.
People, even very smart people, have a habit of lying to themselves when they want something to be true. Obviously religion is a good example of this in the past. And in the present I think we're largely just replacing religion with pseudo-scientific hypotheses to the same end. For instance I personally am a strong believer in the simulation hypothesis, at least I think I am. I don't know whether I "really" believe it's as sound as it seems, or if it's a coping mechanism to balance a secular worldview and the desire to not die. I mean it's not really even a theory since if it turns out to be true, and one day I simply 'wake up' - is that new reality "real" or just another simulation? But I'm at least aware of the fact I may well be lying to myself with a highly debatable theory.
Not arguing against your general point that post-childhood life expectancy has always been fairly high, but I don't think rich aristocrats make for a "nice sample" when talking about longevity.
Most of the logic about endless life expectancy take improvement in healthcare as the fundamental driving factor. And in the past, the wealthy were no better off than the impoverished here because you couldn't buy that which didn't exist. Germ theory didn't exist, let alone antibiotics, even hand washing as a thing before surgery didn't yet exist. And what I was alluding to in my comment was what happened to George Washington. He died at a relatively early age of 67 of a throat infection, or of the 5 pints of blood that was taken from him to 'cure' that infection leaving portraits of him on his death bed as being white as a ghost.
Yeah for sure they were also less likely to end up eating unclean food, involuntarily fall victim to the consequences of war, unable to escape famines (oft related to the former), and countless other such things.
But in many ways I think this is a desirable bias. Because when we look at past vs present life expectancy, what we're mostly interested in, as far as these topics go, is how medical technology is improving things. The implied question is 'What would ones life expectancy be without modern medicine?' And the upper classes of times past basically answer this for us.
The one thing we need to ensure is that we're not picking a literal survivorship bias. So for instance when looking all the way back to Ancient Greece one again finds an average age of death of about 70 years old. But many people point out that if Plato died when he was 20 instead of when he was 80, then we might never have heard of him. So the sample is somewhat biased. This is kind of true, but it's also true that nearly all of these people we would have known about if they died when 40, but anyhow this is all a really annoying and subjective debate - so things like the Founding Fathers are much nicer because there there's 0 argument of survivorship bias.
That's why I always think that the _mean_ life expectancy is a much more useful metric than _average_. Not sure why everybody reports the average everywhere. I have the same exact thought when it comes to salaries. Governments and the like always publish the _average_, which tells very little to the regular person. If anything, it would tell the regular person that they must really be very badly off if most make more than them, having a negative effect. Perhaps that's the desired outcome?
> Not sure why everybody reports the average everywhere.
Because that's the modern definition of life expectancy: the average (mean). Probably because the primary driver behind the production of actuarial tables has always been for insurance, annuities, and similar purposes. For calculating costs and valuations the mean is often a better measure because the distribution of deaths isn't normal. Though in modern actuarial tables you'll often find both.
I would assume popular literature quotes expectancy figures from birth because that's the easiest thing to do when you're just trying to give a single simple figure. But actuarial tables have always been just that--tables. Given a person at age X, what's their life expectancy. The first row will be from birth, but people with money on the line have always understood that number is mostly irrelevant. Here's an actuarial table from the 3rd century which was built for calculating annuities: https://en.wikipedia.org/wiki/Ulpian%27s_life_table Interestingly that table seems to use median life expectancy.
Actuarial science was a significant driver in the development of modern statistics and mathematics, especially as the market for financial products exploded over the past several centuries. The tables and models for life expectancy from 150 years ago were startlingly accurate, even in their forecasts of changing life expectancies. When Social Security was passed in the 1930s the models for how life expectancies would change, both from infancy and across all the age brackets, were spot on with actual changes up to the 1990s.
Even then though, in e.g. Victorian times, the median (50th percentile) gets skewed by horrendously high infant mortality.
Looking at the 75th or 80th percentile, or the life expectancy for an 18 year old, is a better measure. High scores for the 75th can mask deaths due to inequality to some extent, but because wealth distributions are _so_ skewed at the top, the 75th percentile typically looks more like an average/poor person than a rich person.
Yeah, even the median life expectancy in the past would be getting awful close to something like 2 years old. [1] Again running with the Founding Fathers as an interesting example, Sam Adams lived until he was 82 and was one of 12 children. Yet of all those brothers/sisters, only 3 lived past the age of 3.
It's this context that I think explains things like infant 'exposure' in various cultures over time that we can't even imagine today - parents simply leaving their child out to the wilds, essentially to die - while retaining that cognitive dissonance that perhaps he might be found and raised by somebody, as was a frequent component in the hero legends, such as with Theseus and Perseus.
