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Some scary life extension dilemmas

2 Ghatanathoah 01 January 2013 06:41PM

Let's imagine a life extension drug has been discovered.  One dose of this drug extends one's life by 49.99 years.  This drug also has a mild cumulative effect, if it has been given to someone who has been dosed with it before it will extend their life by 50 years.

Under these constraints the most efficient way to maximize the amount of life extension this drug can produce is to give every dose to one individual.  If there was one dose available for all seven-billion people alive on Earth then giving every person one dose would result in a total of 349,930,000,000 years of life gained.  If one person was given all the doses a total of 349,999,999,999.99 years of life would be gained.  Sharing the life extension drug equally would result in a net loss of almost 70 million years of life.  If you're concerned about people's reaction to this policy then we could make it a big lottery, where every person on Earth gets a chance to gamble their dose for a chance at all of them.

Now, one could make certain moral arguments in favor of sharing the drug.  I'll get to those later.  However, it seems to me that gambling your dose for a chance at all of them isn't rational from a purely self-interested point of view either.  You will not win the lottery.  Your chances of winning this particular lottery are almost 7,000 times worse than your chances of winning the powerball jackpot.  If someone gave me a dose of the drug, and then offered me a chance to gamble in this lottery, I'd accuse them of Pascal's mugging.

Here's an even scarier thought experiment.  Imagine we invent the technology for whole brain emulation.  Let "x" equal the amount of resources it takes to sustain a WBE through 100 years of life.  Let's imagine that with this particular type of technology, it costs 10x to convert a human into a WBE and it costs 100x to sustain a biological human through the course of their natural life.  Let's have the cost of making multiple copies of a WBE once they have been converted be close to 0.

Again, under these constraints it seems like the most effective way to maximize the amount of life extension done is to convert one person into a WBE, then kill everyone else and use the resources that were sustaining them to make more WBEs, or extend the life of more WBEs.  Again, if we are concerned about people's reaction to this policy we could make it a lottery.  And again, if I was given a chance to play in this lottery I would turn it down and consider it a form of Pascal's mugging.

I'm sure that most readers, like myself, would find these policies very objectionable.  However, I have trouble finding objections to them from the perspective of classical utilitarianism.  Indeed, most people have probably noticed that these scenarios are very similar to Nozick's "utility monster" thought experiment.  I have made a list of possible objections to these scenarios that I have been considering:

1. First, let's deal with the unsatisfying practical objections.  In the case of the drug example, it seems likely that a more efficient form of life extension will likely be developed in the future.  In that case it would be better to give everyone the drug to sustain them until that time.  However, this objection, like most practical ones, seems unsatisfying.  It seems like there are strong moral objections to not sharing the drug.

Another pragmatic objection is that, in the case of the drug scenario, the lucky winner of the lottery might miss their friends and relatives who have died.  And in the WBE scenario it seems like the lottery winner might get lonely being the only person on Earth.  But again, this is unsatisfying.  If the lottery winner were allowed to share their winnings with their immediate social circle, or if they were a sociopathic loner who cared nothing for others, it still seems bad that they end up killing everyone else on Earth.   

2. One could use the classic utilitarian argument in favor of equality: diminishing marginal utility.  However, I don't think this works.  Humans don't seem to experience diminishing returns from lifespan in the same way they do from wealth.  It's absurd to argue that a person who lives to the ripe old age of 60 generates less utility than two people who die at age 30 (all other things being equal).  The reason the DMI argument works when arguing for equality of wealth is that people are limited in their ability to get utility from their wealth, because there is only so much time in the day to spend enjoying it.  Extended lifespan removes this restriction, making a longer-lived person essentially a utility monster.

3. My intuitions about the lottery could be mistaken.  It seems to me that if I was offered the possibility of gambling my dose of life extension drug with just one other person, I still wouldn't do it.  If I understand probabilities correctly, then gambling for a chance at living either 0 or 99.99 additional years is equivalent to having a certainty of an additional 49.995  years of life, which is better than the certainty of 49.99 years of life I'd have if I didn't make the gamble.  But I still wouldn't do it, partly because I'd be afraid I'd lose and partly because I wouldn't want to kill the person I was gambling with. 

So maybe my horror at these scenarios is driven by that same hesitancy.  Maybe I just don't understand the probabilities right.  But even if that is the case, even if it is rational for me to gamble my dose with just one other person, it doesn't seem like the gambling would scale.  I will not win the "lifetime lottery."

4. Finally, we have those moral objections I mentioned earlier.  Utilitarianism is a pretty awesome moral theory under most circumstances.  However, when it is applied to scenarios involving population growth and scenarios where one individual is vastly better at converting resources into utility than their fellows, it tends to produce very scary results.  If we accept the complexity of value thesis (and I think we should), this suggests that there are other moral values that are not salient in the "special case" of scenarios with no population growth or utility monsters, but become relevant in scenarios where there are.

For instance, it may be that prioritarianism is better than pure utilitarianism, and in this case sharing the life extension method might be best because of the benefits it accords the least off.  Or it may be (in the case of the WBE example) that having a large number of unique, worthwhile lives in the world is valuable because it produces experiences like love, friendship, and diversity. 

My tentative guess at the moment is that there probably are some other moral values that make the scenarios I described morally suboptimal, even though they seem to make sense from a utilitarian perspective.  However, I'm interested in what other people think.  Maybe I'm missing something really obvious.

 

EDIT:  To make it clear, when I refer to "amount of years added" I am assuming for simplicity's sake that all the years added are years that the person whose life is being extended wants to live and contain a large amount of positive experiences. I'm not saying that lifespan is exactly equivalent to utility. The problem I am trying to resolve is that it seems like the scenarios I've described seem to maximize the number of positive events it is possible for the people in the scenario to experience, even though they involve killing the majority of people involved.  I'm not sure "positive experiences" is exactly equivalent to "utility" either, but it's likely a much closer match than lifespan.

Living Forever is Hard, part 3: the state of life extension research

11 gwern 23 April 2012 06:17PM

Previous:

  1. "Living Forever is Hard, or, the Gompertz Curve"
  2. "Living Forever is Hard, part 2: Adult Longevity"

From the excellent Fight Aging! blog comes a pointer to "A Histogram of Results from Life Span Studies", a graph of thousands of animal studies by Kingsley G. Morse Jr. (updated version from mailing list):

 

(This is not the same as a funnel plot, as the y-axis is # of studies finding that percentage gain and nothing to do with the n of studies.)


On the closed GRG mailing list, the compiler says:

Many test the same intervention on a different strain of the same species, or with a different dose.

I asked some questions, and Steven B. Harris replied:

“I was gratified to be able to answer promptly, and I did. I said I didn't know.”  (Twain)

Though I can observe that the center of that distribution isn't very far from no-effect, and one would expect that there's a publication bias toward reporting positive effects vs. null effects. I would think that could account for it entirely.

There's also the problem we've discussed before, that feeling animals stuff they don't like the taste off, amounts to calorie restriction. So this clouds the issues terribly in non-CR studies, unless you're very, VERY careful to control them somehow.

The relevance of this summary graph to news like the C60 rodent life extension experiment is obvious. Reading GRG has been interesting and educational about that experiment; a rough summary of points made by various people including myself:

  • contradictory median/lifespan figures
  • duplicate image
  • small sample
  • doses of C60 small enough that the direct antioxidant activity can't be responsible
  • justifying cites not published when experiment started
  • the C60 was administered for brief period (think the analogy given was 'imagine taking a supplement only during your 40s and doubling your lifespan')
  • the massive life extension observed in the olive-oil-only rats - not doubling, but still really implausible

[link]s Recent developments in life-extension

10 JoshuaZ 02 November 2011 08:54PM

Progeria is a very rare disease which causes children to undergo symptoms extremely similar to rapid aging, and generally dying before the age of 20. Recent results suggest that a fairly cheap drug may help reduce the aging systems, and it is possible it may have similar effects on normal humans. Lay summary by BBC and actual article

On a related note, in a strain of mice which age unusually quickly, there's been success delaying many symptoms of aging by removing senescent cells. Here is the relevant article in Nature.

Curiosity, Adam Savage, and Life-Extension

8 JoshuaZ 17 October 2011 03:17AM

Tonight the Discovery Channel had on their Curiosity series  a program hosted by Adam Savage (of Mythbusters) on whether or not we could live indefinitely. The program probably did have some substantial impact on some people who have not been exposed to that sort of idea before, and may have been especially good at letting people understand that there's a definite possibility that the relevant discoveries might occur in their lifetimes.

However the piece was as a whole decidedly lacking in actual information.  First, the entire program was built around the conceit of Savage looking back from his thousandth birthday and talking about all the technologies that had allowed it to happen. In their hypothetical world, due to a severe car accident in 2022, Savage becomes the first person to benefit from a host of different technologies. There were zero actual interviews with scientists and although actual technological proposals were mentioned such as organ cloning and a brief segment on the SENS work of filtering blood cells, the vast majority was high-budget special effects segements of the new technologies. Also, cryonics was not mentioned at all, since in their hypothetical world, Savage had never needed that particular technology. Similarly, no mention is made of uploading, although Savage does gain cybernetic enhancements to his brain.

At a level of evaluation of narrative rather than  information, the entire piece was a bit incoherent and inconsistent. For example, Savage declares at one point that at age 130, he is then the oldest person in the world. This makes no sense in context since presumably after the basic technologies have been tested out on him they could then be applied to other people, some of whom will be older than he is. In the same section of the narrative, Savage has apparently become the head-engineer of the world's first space elevator construction project. A few centuries later, Savage then has to deal with an asteroid impact obliterating much of North America. My girlfriend remarked that the program came across almost as fanfic about Savage.

Overall, I can't recommend this much but it might do a good job getting people aware of these issues who don't currently know anything.  

Did anyone else see this? What did they think? 

Living Forever is Hard, part 2: Adult Longevity

13 gwern 09 September 2011 06:52PM

Following Fight Aging's "A Primer on Compression of Morbidity" today to Fries's 2011 review article "Compression of Morbidity 1980–2011: A Focused Review of Paradigms and Progress" (Fries, incidentally, introduced the concept of "compression of morbidity" in 1980), I found some interesting details in it.

continue reading »

Living Forever is Hard, or, The Gompertz Curve

46 gwern 17 May 2011 09:08PM

I recently recalled, apropos of the intermittent fasting/caloric restriction discussion, a very good blog post on mortality curves and models of aging:

For me, a 25-year-old American, the probability of dying during the next year is a fairly miniscule 0.03% — about 1 in 3,000.  When I’m 33 it will be about 1 in 1,500, when I’m 42 it will be about 1 in 750, and so on.  By the time I reach age 100 (and I do plan on it) the probability of living to 101 will only be about 50%.  This is seriously fast growth — my mortality rate is increasing exponentially with age.

...This data fits the Gompertz law almost perfectly, with death rates doubling every 8 years.  The graph on the right also agrees with the Gompertz law, and you can see the precipitous fall in survival rates starting at age 80 or so.  That decline is no joke; the sharp fall in survival rates can be expressed mathematically as an exponential within an exponential:

P(t) \approx e^{-0.003 e^{(t-25)/10}}

Exponential decay is sharp, but an exponential within an exponential is so sharp that I can say with 99.999999% certainty that no human will ever live to the age of 130.  (Ignoring, of course, the upward shift in the lifetime distribution that will result from future medical advances)

...There is one important lesson, however, to be learned from Benjamin Gompertz’s mysterious observation.  By looking at theories of human mortality that are clearly wrong, we can deduce that our fast-rising mortality is not the result of a dangerous environment, but of a body that has a built-in expiration date.

gravityandlevity then discusses some simple models of aging and the statistical characters they have which do not match Gompertz's law:

  1. 'lightning' model: risk of mortality each period is constant; Poisson distribution:

    What a crazy world!  The average lifespan would be the same, but out of every 100 people 31 would die before age 30 and 2 of them would live to be more than 300 years old.  Clearly we do not live in a world where mortality is governed by “lightning bolts”.

  2. 'accumulated lightning'; like in a video game, one has a healthbar which may take a hit each period; similar to above:

    Shown above are the results from a simulated world where “lightning bolts” of misfortune hit people on average every 16 years, and death occurs at the fifth hit.  This world also has an average lifespan of 80 years (16*5 = 80), and its distribution is a little less ridiculous than the previous case.  Still, it’s no Gompertz Law: look at all those 160-year-olds!  You can try playing around with different “lightning strike rates” and different number of hits required for death, but nothing will reproduce the Gompertz Law.  No explanation based on careless gods, no matter how plentiful or how strong their blows are, will reproduce the strong upper limit to human lifespan that we actually observe.

What models do yield a Gompertz curve? gravityandlevity describes a simple 'cops and robbers' model (which I like to think of as 'antibodies and cancers'):

...in general, the cops are winning.  They patrol randomly through your body, and when they happen to come across a criminal he is promptly removed.  The cops can always defeat a criminal they come across, unless the criminal has been allowed to sit in the same spot for a long time.  A criminal that remains in one place for long enough (say, one day) can build a “fortress” which is too strong to be assailed by the police.  If this happens, you die.

Lucky for you, the cops are plentiful, and on average they pass by every spot 14 times a day.  The likelihood of them missing a particular spot for an entire day is given (as you’ve learned by now) by the Poisson distribution: it is a mere e^{-14} \approx 8 \times 10^{-7}.

But what happens if your internal police force starts to dwindle?  Suppose that as you age the police force suffers a slight reduction, so that they can only cover every spot 12 times a day.  Then the probability of them missing a criminal for an entire day decreases to e^{-12} \approx 6 \times 10^{-6}.  The difference between 14 and 12 doesn’t seem like a big deal, but the result was that your chance of dying during a given day jumped by more than 10 times.  And if the strength of your police force drops linearly in time, your mortality rate will rise exponentially.

... The language of “cops and criminals” lends itself very easily to a discussion of the immune system fighting infection and random mutation.  Particularly heartening is the fact that rates of cancer incidence also follow the Gompertz law, doubling every 8 years or so.  Maybe something in the immune system is degrading over time, becoming worse at finding and destroying mutated and potentially dangerous cells.

...Who are the criminals and who are the cops that kill them?  What is the “incubation time” for a criminal, and why does it give “him” enough strength to fight off the immune response?  Why is the police force dwindling over time?  For that matter, what kind of “clock” does your body have that measures time at all? There have been attempts to describe DNA degradation (through the shortening of your telomeres or through methylation) as an increase in “criminals” that slowly overwhelm the body’s DNA-repair mechanisms, but nothing has come of it so far.

This offers food for thought about various anti-aging strategies. For example, given the superexponential growth in mortality, if we had a magic medical treatment that could cut your mortality risk in half but didn't affect the growth of said risk, then that would buy you very little late in life, but might extend life by decades if administered at a very young age.

Life Extension through Diet Modification

17 Caerbannog 16 May 2011 06:36PM

Life extension is a relevant topic here, and I was wondering if people are aware of the apparently life-extending effects of calorie restriction (CR) and intermittent fasting (IF). To the extent of my knowledge, this is the best method using currently realized technology that has shown repeated and significant life-extension benefits.

Studies show that reducing calories by 20% to 40% from ad libitum feeding (but maintaining the supply of required protein and micro-nutrients) gives improvements in markers related to aging, and extends life span in rodents and other organisms.

Other rodent studies have also shown similar results in subjects which were kept on various intermittent fasting schedules. Rats that were fed only on alternating days gained up to 25% lifespan (see Table 2).

The benefits of IF are seen even if the total calorie intake is the same as in ad libitum subjects.

There are ongoing full-lifespan studies in rhesus macaques to test the effects in primates, but none of these studies have completed. This abstract of the interim results appears promising, though.

Studies of CR and IF on humans have shown effects consistent with reduced mortality, including:
- Improved triglyceride profiles (a marker for heart disease)
- Increased insulin sensitivity
- Reduced cell proliferation (a marker for cancer)

Generally, these diet modifications appear to not just extend life span, but improve the quality of life too. In aged subjects they improve things like: muscle mass, cognition, energy, appearance, and activity level.

Have people heard about this or tried it? If you are trying to maximize your chance of surviving to the point that technology can lengthen lifespan indefinitely, it seems like something worth exploring.

I tried an IF schedule for about 6 months during 2010. I followed a schedule of 3 x ~thirty hour fasts every 7 days and found it somewhat tolerable. I exercise regularly and found that exercising on the non-fasting days was not a problem. I'm thinking of starting up such a schedule again.

Resveratrol continues to be useless

6 gwern 10 October 2010 12:19AM

From the more-bad-news-for-those-who-want-to-live-forever department: http://pipeline.corante.com/archives/2010/10/08/does_resveratrol_really_work_and_does_srt1720.php

The current study dials that back to levels that could be reached in human dosing. What they saw was no effect on lifespan at 0.5 micromolar, which would be a realistic blood level for humans. When they turned up the concentration to 5 micromolar, there was a slight but apparently real effect of just under 4%. Now, 5 micromolar is a pretty heroic level of resveratrol - I think you could hit that as a peak concentration, but surely not hold it.

Nor is the bad news just for resveratrol:

Oh, and there's another interesting part to this paper. The authors also looked at SRT1720, the resveratrol follow-up from Sirtris that has been the subject of all kinds of arguing in the recent literature. This compound is supposed to be several hundred times more potent than resveratrol itself at SIRT1, although if you've been following the story, you'll know that those numbers are widely believed to be artifacts of the assay conditions. And sure enough, the authors saw no effect on C. elegans lifespan when dosing with physiological concentrations of SRT1720.