The Probability that Cryonics will work

This analysis has sometimes been compared with Pascal's Wager...

Estimating the odds

People often ask "What is the probability that cryonics will work?"

The short answer: discounting dystopian futures, assuming a good quality of cryopreservation, and assuming that molecular nanotechnology (or MNT) is developed more or less as expected, the overall probability of success seems quite high - likely exceeding 85%. How we arrived at this answer? The simplest framework is to break down the probability of success into separate independent variables and then analyze each variable. This task is not as easy as it looks.

1. You must avoid Information-theoretic death.

The destruction of the information within a human brain to such an extent that recovery of the original person is theoretically impossible by any physical means

2. Technology to revive you must be developed and applied.

This framework is intended to provide clearly independent probabilities, so that multiplication of the probabilities can be used to draw conclusions about the overall probability of success.

Information Destruction, in the extreme, is that the patent’s memories, personality, hopes, dreams, etc. have been destroyed. Perhaps the most significant risk is caused by deterioration of the brain prior to legal death from neurodegenerative diseases We can reasonably expect that the technology required to revive a cryopreserved patient and restore them to health will also be able to reverse dementia, but The extent of such irreparable memory loss (as opposed to damage to retrieval mechanisms) is not known at this time. We cannot, at the present time, distinguish reliably between these two possibilities in most cases. What is "unacceptable memory loss? The answers are likely to vary widely from person to person.

Future Medical Technology will be no mere incremental or evolutionary advance over today's medicine. The coming ability to arrange and rearrange molecular and cellular structure in almost any way consistent with physical law will let us repair or replace almost any tissue in the human body. Whether it's a new liver, a more vital heart, a restored circulatory system, removing some cancerous cells, or some other treatment -- at some point, nanomedicine should let us revitalize the entire human body and even revive someone who was cryopreserved today. And, also the interesting discussion The Molecular Repair of the Brain:

Those interested in pursuing this subject should read:

Cryo-probability which discusses the chances of success

http://merkle.com/cryo/probability.html The Molecular Repair of the Brain which discusses repair technologies that are clearly feasible in principle


At some future date, we will have direct experimental proof that today's Cryopreserved patients either can or cannot be revived by future medical technology. Unfortunately, most of us must decide today if we wish to pursue this option.

It is worth pointing out that a fairly wide range of simple tissue types have been successfully Cryopreserved and then re-warmed, including very early human embryos, sperm, skin, bone, red and white blood cells, bone marrow and others.

How might we evaluate Cryonics?

Broadly speaking, there are two available courses of action:

(1) Sign up or (2) Do nothing.

Cryonics Payoff Matrix

  It works It doesn't work
Sign up Live Die, lose life insurance
Do nothing Die Die

And there are two possible outcomes:

(1) It works or (2) It doesn't.

This leads to the payoff matrix.

In using such a payoff matrix to evaluate the possible outcomes, we must decide what value the different outcomes have.

What value do we place on a long and healthy life?

What does Cryonics cost and what (presumably negative) value do we place on being dead?

In the absence of direct experimental results in one direction or the other, what estimate do we make of the chances that it will work?

These are all question that the individual must answer for him or herself in making a decision as to whether to commit valuable resources to this end-of-life choice. It is due diligence, pure and simple.

The probability that cryonics will work is X

Both critics and supporters have made specific probability estimates about how likely cryonics is to work. In its worst form such probability assessments convey nothing more than putting a number on overall feelings of pessimism or optimism. More serious attempts have been made to calculate a specific probability that cryonics will work. Such attempts usually go as follows: A number of independent conditions (or events) for cryonics to work are distinguished, these conditions are “assigned” a probability, and the total (or joint) probability is calculated by multiplying them. Although such calculations give the semblance of objectivity, they are equally vulnerable to the fundamental objection that assigning one single number to the probability that cryonics will work is just a lot of hand waving. How many independent events are there and how do we know that they are independent? What is the basis for assigning specific probabilities to these conditions? What are the effects of minor changes in the numbers?

Probability calculations are not completely useless. They can help us in identifying important conditions that need to be satisfied for resuscitation. They can also help identify weak links that can be improved. But probability estimates can be dangerous as well when we take them too seriously and discourage people from making cryonics arrangements. The point here is not that we should refrain from being skeptical but that if we make quantitative estimates we should be able to back up our statements with rigorous arguments or just confine ourselves to more qualitative statements. Another objection to making cryonics probability estimates was made by the cryonics activist and mathematician Thomas Donaldson. He makes the common sense point that many of these conditions are not independent of what we do. We can make a contribution to increasing the probability that cryonics will work.

Last but not least, what does it mean when we talk about “cryonics working?” It is conceivable that cryonics will work for one person but not for another, reflecting improved technologies and protocols. Perhaps asking the question if cryonics patients can be “revived” is the wrong question. As the cryobiologist Brian Wowk has pointed out, the real question is how much original personality would survive the many possible damage/repair scenarios, not revival per se. Survival in medicine is not a simple black-and-white issue, as evidenced by people who recover from stroke or cardiac arrest but with personality and memory alterations. And it is worth mentioning once more that how much of our personality survives depends on what we do to improve the quality and long-term survival of our cryonics organizations.

The expected value of the outcome should exceed the decision cost for your immortality project to be undertaken.

A newly minted Cryonicist (DPR) reviews his decision process in simple but realistic terms:
DPR is now a Full-Fledged Cryonicist

Nov 1, 2012

How much is your life worth to you?

If you suffered from a disease which might strike you down at any time; and a treatment was available, which cost six thousand dollars per year... would you be willing to scrape together that much cash for it? If the best available treatment only had a fifty percent chance of success... would you be willing to pay three thousand a year it? If the best available treatment only had a five percent (5%) chance of success... would you be willing to pay three hundred a year for it?

My own answers to all three questions are 'yes'.

After reading and researching about cryonic preservation, my best estimate of its success - that is, eventual revival - is somewhere in the neighborhood of five percent. I have also learned that arrangements can be made for one's own cryonic preservation for around three hundred dollars per year. I have filled out the forms, signed the paperwork, sent in my first installment. (If you want to know how to sign up yourself, feel free to ask.) Put simply - I'm putting my money where my mouth is.

Medically, the procedure I have signed up for isn't "freezing", which involves ice; instead, it's "vitrification", which lowers the body's temperature in a way that avoids the creation of tissue-damaging ice crystals.

Legally, according to the "Uniform Anatomical Gift Act" of my cryonic provider's location, and the "Trillium Gift of Life Act" of my home province, what I've actually signed up to do is donate my whole body for scientific research. There's no actual guarantee that, if vitrified, I will ever be revived - though that is the goal being aimed for.

Philosophically, I have not encountered any significant evidence in support of the idea of an immortal soul. The best conclusion I've been able to reach is that minds are processes created by brains, and when the brain is sufficiently damaged, the mind ceases to exist, like a candle blown out. If it's possible to avoid dying, I'd rather avoid it; and for a number of causes of death, like getting hit by a car, there aren't really any ways to avoid them, and only a few possible ways to even potentially survive such lethal levels of damage to the body... but people keep coming up with new tricks all the time, and it's possible that whatever does end up killing me will be curable at some point in the future and it's also possible that the vitrification process will be reversible at some point in the future. I've already mentioned my estimate of that possibility (5%).

As for the life insurance, I am thinking of a 20-year term policy with RBC (Royal Bank of Canada). If anyone has any additional information to impart please let me know as some questions still persist. Have you had any dealings with these cryonics insurance policies previously, to know whether or not there will be any problems naming the Cryonics Institute as the beneficiary? Do you have any recommendations about how large a benefit in excess of the basic USD $35,000 amount the policy should pay out, such as to cover currency-exchange fluctuations or the 'local help' rider? Is there anything else you would recommend be discussed before I make that initial insurance payment and “set the ball in motion” (beyond the membership commitment)?

So... if I don't manage to live long enough for a technological Fountain of Youth to be discovered, then, if all goes well (or at least as well as possible, given that I'll be dead), my body will be transformed into a glass statue - and, like Sleeping Beauty, like Rip Van Winkle, like the various Kings Sleeping Under the Mountain... like Han Solo in carbonite, like Dave Lister, like Khan Noonien Sing, like Ellen Ripley, like Philip J. Fry, like Captain America in the iceberg, like Buck Rogers... like Rana sylvatica... I will await the possibility of my eventual awakening.

And, if it doesn't work, then, worst-case scenario is that I just stay dead. Which is what would happen if I never signed up for cryo in the first place.

Thank you for your time,