Information on my genes provided by 23andMe and Promethease

Finally got my DNA analysis back from 23andMe:

Since the FDA stopped allowing them to interpret the data for their customers, I had to spend an extra $5 with https://promethease.com/ to get useful information out of it.
Here's the most interesting and useful stuff they found:

gs 229 & i3003137(A;T)- Sickle cell trait; resistant to malaria but a carrier for sickle cell anemia. Note some believe gs229 individuals should be identified by screening before being exposed to extreme physical exertion due to ~30x higher risk for sudden death
 Sickle Cell Anemia carrier - "Bad news: You are a carrier for Sickle Cell Anemia. You should consider having your partner tested before before having children. The good news is that you are naturally resistant to malaria."
[I learned this at Coast Guard bootcamp. The info the doctor gave me said there is rarely any real life effect, other than sudden death during extreme activity such as mountain climbing or... military bootcamp! I didn't die though :P ]

gs251 - Beta Thalassemia carrier (Beta thalassemia is a hereditary disease affecting the hemoglobin - similar to sickle cell)
[I guess I should go visit the tropics, take advantage of the fact that I am malaria proof]

rs738409(G;G) - higher odds of alcoholic liver disease, increased liver fat While found in 55%+ of all people, alcohol seems to be 3x more damaging to your liver than typical
[That's ok, I rarely drink anyway]

rs7294919(C;T) Moderately enhanced hippocampal volume
The hippocampus is a critical brain structure involved in learning and memory. In particular, it is associated with the ability to form long-term memories of facts and events

rs2237717(T;T) - roles in general neurodevelopment and in the development of autism . Rs2237717 has been linked to schizophrenia, and the ability to recognize facial emotion.  Possible cancer protection.
[I've always suspected I may have just a touch of Asperger's / ASD.  Not enough to be diagnosable, but enough that I often sympathize more with the experience of aspys than of NTs.  Wonder how much of that is related to rs2237717(T;T) ]



rs11614913(C;C) - increased risk of various types of cancer

rs2180439(T;T) - 2x increased risk of Male Pattern Baldness
[Well, I was already aware of that.  But...]

rs925391(T;T) - unlikely to go bald
[So maybe it won't be completely?]

rs1800497(C;C) Learns from mistakes more easily. Men may have a higher risk of Obsessive Compulsive Disorder but lower risk of ADHD. Lower risk of alcoholism and smoking addiction. Faster recovery from traumatic brain injury. Lower obesity due to increased pleasure response to food
[well now that is interesting!  A number of people have commented that they find it strange that I'm not particularly excited by food, that my hunger is more than my appetite, and sometimes I don't feel like taking the effort to prepare food.]

rs72921001(C;C) - More likely to think cilantro tastes like soap
[AH HA ha ha ha!  Hmm.  I don't think I think cilantro tastes like soap, but now I really want to find some and taste it!]

rs3732379(C;T) - reduced risk of acute coronary events

rs53576(A;G) - oxytocin receptor polymorphism (OXTR)

You have a SNP in the oxytocin receptor which may make you less empathetic than most people.
[I wonder how many people who know me will be surprised by that :P ]
When under stress you may have more difficulty recognizing the emotional state of others which impacts loneliness, parenting, and socializing skills
Lower levels of reward dependence (reliance on social approval). Lower autonomic arousal while perceiving harm to others.
[I object to the characterization of this as "dysfunction".  It is different than the norm, sure.  But just because I can't tell how you feel from your expression doesn't mean I'm any less likely to care.  It just means I need more explicit communication - which is generally a good thing anyway.  
Combined with good communication, I bet it makes for less misunderstandings: while I do worse than average on 
"Reading the Mind in the Eyes Test", I KNOW when I'm not sure, while people who do better are often confident even when they are wrong.  Therefor I'm more likely to ask.
Also, reliance on social approval isn't really a good thing.
This study http://mic.com/articles/92479/psychologists-have-uncovered-a-troubling-feature-of-people-who-seem-too-nice isn't really about "niceness" as it claims, so much as about the politeness that stems from a high reliance on social approval.  In other words, ASDs are a lot less likely to hurt others in order to fit in or be accepted.
Lower autonomic arousal while perceiving harm to others is probably a trait you want in a rescuer (USCG Search and Rescue, for example) - similar as I said above, the fact that I don't have a strong emotional reaction to your distress doesn't mean I don't care.  It means I can stay calm and collected during you crises, which makes me more effective at helping you.  Do you really want your rescuer to be so sympathetic that they freak out and start crying when they see how much pain you're in?]

gs128 & i4001527(D;I) - Blood type O+

rs601338(A;A) - Immunity to Norovirus
[One more reason to travel]

rs1815739(T;T) - Impaired muscle performance. Fast-twitch muscle fibers completely unable to produce alpha-actinin-3.  (poor sprinting and maximal strength). No apparent effect on slow twitch (endurance) fibers.
[That sucks.  It explains why, even when I do everything I'm supposed to in terms of strength training program, rest, nutrition, and supplementation, I still progress so much slower than others.  Oh well, at least now I know its not my fault]

gs100 & rs182549(C;C) - 77% risk of lactose intolerance
[Interesting.  I'm not.  Dairy is probably 25% of my calorie intake, no effects on me at all]

rs2943634(A;A) - lower risk of ischemic stroke

rs807701(C;C) and rs793862(A;A) - 3-5x increased dyslexia rsik

rs9273363(C;C) - Much lower (0.15x) risk of Type 1 Diabetes

rs1800955(C;T) - increased susceptibility to novelty seeking (due to less-efficient serotonin processing)
[I've noted in the past that of the major characteristics of ASD, the primary ones I lack is desire for routine and repetition.  I do in fact get bored easily, which is the main reason I have quit every 40-hour a week job I've ever had, and only managed to stick with my current "career" by having 5 different jobs]

gs184 - able to taste bitterness.  You can taste propylthiouracil (PROP), PTC, and related chemicals.  Coffee and dark beers also tastes more bitter.
[Interesting.  So maybe everyone else isn't just deluding themselves into thinking those things taste good just because they enjoy the effects of intoxication.  Other people actually experience something different than I do when they taste them!]

gs157 & rs762551(A;C) - enhanced stimulation by caffeine
[I bet another significant reason is because I almost never use it, so my tolerance is normally zero]

rs5751876(T;T) - significantly higher anxiety levels after moderate caffeine consumption
[hmmmm... I've always assumed I don't care for the taste of coffee, tea, cola, and chocolate just because they taste bitter.  But maybe there's also a subconscious factor from my brain noticing the negative effect caffeine has on me.  I've never noticed it consciously those times I have consumed a lot though]

rs17070145(C;T) - increased memory performance (20%!)

rs1799990(A;G) - Resistance to Prion Disease (PrP 129 Met/Val heterozygote) [the human form of Mad Cow Disease]
" this genotype prevents transmission of kuru, a form of Prion disease transmitted by cannibalism. So eat as many brains as you want!"

The downsides to empathy

"You have a SNP in the oxytocin receptor which may make you less empathetic than most people. 
When under stress you may have more difficulty recognizing the emotional state of others which impacts loneliness, parenting, and socializing skills 
Lower levels of reward dependence (reliance on social approval). Lower autonomic arousal while perceiving harm to others." 

Indeed, I've been told by many people that I am not empathetic enough, and I have social skills only slightly better than someone with Asperger's. 

But I object to the characterization of this as "dysfunction". It is different than the norm, sure.
Does empathy imply more morality?  Is lack of empathy a pathology? Not necessarily


Just because I can't tell how you feel from your expression doesn't mean I'm any less likely to care. It just means I need more explicit communication - which is generally a good thing anyway. 
Combined with good communication, I bet it makes for less misunderstandings: while I do worse than average on "Reading the Mind in the Eyes Test", I KNOW when I'm not sure, while people who do better are often confident even when they are wrong. Therefor I'm more likely to ask. 

A study published in the journal Science by Dr. Hillel Aviezer of the Psychology Department of the Hebrew University, together with Dr. Yaacov Trope of New York University and Dr. Alexander Todorov of Princeton University, confirms my theory: "viewers in test groups were baffled when shown photographs of people who were undergoing real-life, highly intense positive and negative experiences. " (as opposed to the typical "Reading the Mind in the Eyes Test" which uses actors). "When the viewers were asked to judge the emotional valences of the faces they were shown (that is, the positivity or negativity of the faces), their guesses fell within the realm of chance. " 
http://www.sciencemag.org/content/338/6111/1225 
Nobody can really "mind read". But people rated more empathetic absolutely believe they can. Sounds like dysfunction... 

Reliance on social approval is a terrible thing! 
This study http://mic.com/articles/92479/psychologists-have-uncovered-a-troubling-feature-of-people-who-seem-too-nice isn't really about "niceness" as it claims, so much as about the politeness that stems from a high reliance on social approval. In other words, ASDs are a lot less likely to hurt others in order to fit in or be accepted.
The typical human will deliberately choose what they know to be a wrong answer, just so they can fit in with everyone else: http://www.simplypsychology.org/asch-conformity.html
 Reliance on social approval is the basis of peer pressure, of group think, of failure to act in crises (if others are around), of the negative feelings of shame and low-self-esteem. And as the study above shows, it makes people more likely to be evil. I'm at a loss for what positives come from it. It sounds an awful lot like dysfunction to me. 

Lower autonomic arousal while perceiving harm to others is probably a trait you want in, say, a rescuer (USCG Search and Rescue, for example, which I am, or a firefighter or cop or paramedic) - similar as I said above, the fact that I don't have a strong emotional reaction to your distress doesn't mean I don't care. It means I can stay calm and collected during your crises, which makes me more effective at helping you. Do you really want your rescuer to be so sympathetic that they freak out or start crying when they see how much pain you're in? 
A highly sympathetic pediatrician would develop lots of stress from continually causing children pain, even though they know the shots are in the child's best interests. Again, that sounds like dysfunction to me. 

Aspys and similar folk tend to be more intelligent and better at all sort of tasks. The fact of being less common doesn't automatically imply pathology - if it did, being overweight would have to be reclassified as normal, and a healthy BMI would have to be considered disfunction (at least in the US). 
Evolution has gone from pure stimulus response to instinct behavior to emotional reactions to higher order reasoning and logic. I propose the rise of the Aspys, who are less emotional and more logical, is another step in that direction!

Healthcare: the last mainstream superstition

Question:

Have you ever taken a drug that you know for sure works, because you could feel the difference it made?

Unless you happen to be both a pharmaceutical researcher and a theoretical psychologist, you almost definitely answered "yes" to that question.

You thought back to pain pills you've taken, allergy medication, cold remedies, a round of antibiotics, and you experienced the change, you felt it working.  At least, you believe you felt it.

But you are mistaken.  Even if you really did feel something, it is not remotely near enough for you to use the phrase "know for sure".

It simply isn't humanly possible.

There are literally hundreds of steps that could introduce error into the process, from the complexity of biology, to the limitations of awareness, perception, and memory, from the placebo effect and the power of expectation, to dozens of cognitive biases and ways that the human mind is predictably irrational.

If you have been reading my blog a while, you have likely seen all of those links before, but if not - or if you never actually clicked on them and watched or read what they link to - it would be worth while to check them out - especially if you're one of those sort of people who has a body.  If you have ever been to a doctor, taken any form of medicine, ever been sick, ever been injured, or if there is any chance you might ever do any of those things in the future, it would be to your great benefit to read and understand the information at all of those links.

Unless you have read those, everything I write next will be a lot easier to write off and disregard, but for those who have seen them before, I don't want to be too repetitive.
So go click some links, spend a few hours learning, come back and read this here post some other time...

...

Oh, hi!
You're back I see.  That's some crazy stuff, right?  I'm totally not over it yet either.  But hey, this is the world we live in, we gotta work with what we got.

For some reason that I have never even heard a good theory on, American's are apparently far more prone to believing crazy stuff than most of the rest of the developed world.  We have a disproportionate amount of creationists, astrologists, people who believe in ghosts and ESP and faith healing and magnet healing, and "energy fields", people who deny global warming and embrace supply side economics, people who are opposed to vaccines and any form of genetic engineering.

The proportion of people who buy into any one of those examples, however, is less than half - anti-science ignorance is widespread, but it isn't quite mainstream.

There is one area though, where being anti-science is so prevalent that an entire industry is built up around it, and that's health care.

We have the term "alternative medicine".  That's a thing.

What is it an alternative to?  Well... any medicine which has independently and objectively been shown to be effective at treating whatever it is it claims to treat.
Because the term for something which actually works is just "medicine".

No other area of life has an equivalent.

There is no "alternative math", where people base calculations on numerology.
There isn't an "alternative chemistry" industry, which seeks to revive the forgotten wisdom of alchemy.

There is also not many other ways where going backwards is seen as a good thing.  Few people cook over a log fire instead of using natural gas or electricity, based on the fact that people cooked over open fires for thousands of years and therefor it must be better. Other than Richie Norris, no one suggests we should go back to living in teepees. Nobody is seriously advocating we replace telephones with smoke signals or email with pony express riders for long-distance communication.
Health care is the one area where a very significant portion of the population sees ignoring all the progress science has made in understanding how things work as being a good thing.

Of course no one consciously thinks of it that way.  The term is "traditional", not "obsolete".  The reasoning is that people did things a certain way for a really long time, therefor it must be valid.  Presumably if it didn't work people would have given it up by now. 

But we are selective in which invalidated treatments we keep.  Pretty much no one advocates bloodletting, but there are many who take sticking needles in the skin as a serious form of health care.  We are done with trepanation, but you can get health insurance to pay for vertebral subluxation treatments.  Few people think exorcism will cure anything, but, somehow, homeopathy still exists - its silly to even investigate it, because its just water.  There is literally no active ingredient in most homeopathic remedies.   Belief in the four humors is past tense, but there is no challenge in finding people who believe in mysterious "energy fields" around living things.

Don't get me wrong - there really are energy fields.  But they aren't mysterious.  Humans have figured this stuff out.  There are 4 types of force in the universe: 2 types of nuclear force, gravity, and electromagnetism. We all know how gravity works - heavy stuff pulls toward other heavy stuff.  In our daily experience the planet is by far the heaviest thing around, so that means everything gets pulled toward Earth.  Nuclear forces keep all matter together, but we really only interact with it in bombs and power plants.  That leaves electromagnetism, which is fully understood by science, but isn't quite common knowledge yet.

Brief digression for a general science lesson:

Almost everything we commonly think of as "energy" is some form of electromagnatism.  Electricity, obviously.  And magnets.  The entire planet is covered in a giant magnet field, which is why compasses point North.  You can actually see it at the poles, in the form of the Northern (and Southern) Lights

If you can remember back to high school science class, you may realize the close relationship between electricity and magnets: wrap a live wire around a piece of iron, you have an electromagnet.  Move a magnet back and forth inside of a coil of wire, it generates electricity.  That relationship is how every electric generator and every electric motor works.
Then there are electromagnetic waves.  Sounds fancy and sciency, right?  Its just the technical term for "light".  It's all light waves.  Like, the stuff you can see with your eyes, blue and purple and green.
All the different colors of light are arranged in order of how big the light wave is: purple has a small light wave, red has a big one.  That's why rainbows in the sky are in the order they are in.  You can't see it, but the rainbow keeps going, in both directions.  Above purple is ultraviolet (Latin, for "above violet" - hey, what do ya know about that!).  We can't see it with our eyes, but it is there.  If you happened to be a bee, you would see it.  Below red is infrared ("below red") light.  Again, our eyes can't see it, but it is there.  If you put a thermometer just below the red light coming off of a prism, you will see it gets hotter as you go down from purple toward red, and gets even hotter just below red.  Infrared light is where heat lamps get their heat, and it's what night vision goggles see.

But it doesn't stop there.
Microwaves, TV and radio signals, cell phone signals, x-rays, WI FI, radar, it is all light.  A microwave is just a color.  One which the human eye can't see, but the only difference between microwaves and blue is the size of the wave.  All an antenna is is a mechanical eyeball.  A radio sees radiowaves just like your eye sees green.

Even if you personally don't fully understand all the details, realize that it isn't a mystery, all this is very well understood.  It isn't even all that complex.  We know how energy works.  If there is a "life force", it is within the forces that exist in the universe.  And in fact, our nervous system runs on electricity.  Our thoughts, our movements, every part of being alive, it is all powered by chemical energy, adenosine triphosphate breaking down to adenosine diphosphate, and releasing electrically charged ions that can do work in the process.  If you click that last link and try to read it, unless you happen to have been a molecular biology major, chances are most of it is hard to follow.  The important thing to realize is that, as insanely complex as living things are, we have an amazingly high amount of this stuff figured out.

Very few of us fully understand all the details of electronics and computers, down to both the resistor, capacitor and transistor level of the hardware and the line by line code of the software, but we all accept that it is understood, that it works, and we don't reject laptops and cellphones in favor of mysticism, ancient or modern, eastern or western. 

So I was wondering, why do we reject everything biology has learned in favor of tradition?  Why, when science understands biology so well, does such a huge proportion of the population choose to deliberately seek out health care practices and practitioners which explicitly reject the most basic principal of science: "check that you're right"?

I have a few theories.

I suspect the theories are all right, to one degree or another, and they all work together and reinforce each other.

-As complex as computers and airplanes and GPS and every other area of technology is, as complex as meteorology and geology and astronomy are, all of it pales in comparison to molecular biology.

Take this example:

That is fucking mind blowing!  I can barely keep up, but it is... how do you even put it into words?  All those things are going on inside of your body, right now.  And it's just one tiny set of many examples of cellular processes.  There are thousands more like it, and some set of those thousands are happening in every one of your 100 trillion cells 24 hours a day, from conception until several minutes after death.

It is totally overwhelming.

Wouldn't it be nice if it could all be simplified to something a person can wrap their mind around, like "life force", or "positive energy" or "qi"?  Wouldn't it be nice if, instead of having to understand all that amazingly wonderful reality, all health could just be a function of, say, eating the right things or of spinal alignment?

We tend to think of the body like a complicated machine.  When a machine breaks, there is always some specific part that needs fixing or replacing - make the right adjustment, everything is as it should be.

But living things are really nothing at all like machines.  Metabolism is not like burning fuel.  Our joints are not hinges or pivots.  We are more like a bag of soup.  A bag of soup with a frame - but the joints of the frame, instead of being held together by pins, they are held together by strong rubber bands and cushioned by mushy padding.  We are more like a wobbly marionette than a rigid robot.

If the human body is essentially a big chemical bag of soup, and our skeleton is held together by stretchy bendy tendons and ligaments, that rather undermines the entire concept of body "alignment".  What exactly is it being aligned with, and what stops it from lining up "right" on its own?  This doesn't just undermine chiropracty - it undermines most of medical massage, orthopaedic surgery, sports physiology, and physical therapy.

The idea that manipulating body parts, putting them in the "correct" position, stems from thinking of the body as mechanical, when in fact it is fluid and flexible and far more complex than any machine ever built.

Another possible reason for the popularity of anti-science in healthcare, besides for being far more complex than any other area of potential human knowledge, biology and medicine is far more personal.  Nobody is ever going to interact with a neutrino.  Understanding the Higgs Boson doesn't affect your daily life in anyway.  So it's fairly easy to accept that some other people, for whom that is their specialty, know what that stuff is, and you can just trust them on it.  Since everyone has a body, and the health of it is arguably the single most important thing in your life, everyone has incentive to want to know what the hell is going on.

 An answer - any answer - always feels better than "I don't know".  It just feels terrible to have a vague ambiguous open-ended question; especially if its something with a real effect on day to day life, like a disability, illness, or pain.

And an answer we can't comprehend sometimes feels as bad as no answer at all.  

It is an unfortunate side effect of how human psychology works that we feel better having a concrete - but wrong - answer than having one that is accurate, but confusing.

And compounding that, the complexity of molecular biology is so great that, even as much as scientists do know, there is still a huge amount they don't - so in addition to the real answers being confusing, sometimes nobody has an answer at all.

If 10 doctors and specialists say "we don't know", and then one seems confident that they have the answer, we are inclined to accept that last answer, even if we might not have otherwise, because there is nothing better being offered.  But sometimes "nobody really knows" is the most honest answer.  When things are really complex and/or controversial, a professional's confidence should make you less trusting of their opinion, not more.  That confidence is coming from faith.  Faith is the antithesis of science.  It means just making something up, and deciding it's right, without doing the work to double check.

Very closely related to the last reason, it always feel better to do something than to do nothing.  People say that explicitly in times of desperation: "I can't just sit back and do nothing".  But sometimes nothing anyone does will help.  Sometimes doing anything makes it worse.  In the game of soccer, when one team kicks a penalty shot, the statistics say that the goalie has the best chance of blocking the ball if he just stays in the center.  The kick is so fast it is humanly impossible to predict which way it will go.  But almost every goalie, every time, will dive either left or right, and game after game, the kicker scores a goal as the goalie dives out of the way, just because he felt he had to DO something. Because if he just stood there, he would feel like an idiot.

But the truth is: 

Living things have been figuring out how to exist for 3 billion years.  

Without any form of medicine.  

Not modern science based, not alternative tradition based.  

Not any kind.  

Any living thing that hasn't figured out how to heal itself, how to naturally be in optimal alignment, how to get the correct nutrients via appetite, repair its own damage, and generally optimize its own health, went extinct long before humans existed.

Every single day, even without injury or illness, your body creates 300 billion new cells, to replace old worn out ones.  You may have heard the claim that the entire body is replaced every 7-10 years.  It isn't exactly right - different body parts renew at different rates.  Some take 16 years.  Some are replaced every few days.  But, aside from brain cells, your entire body really does replace itself on an ongoing basis.

This is how you heal after injury.  Give the body enough time, and it will replace damaged cells, without you doing anything at all.
Our immune system is more powerful and effective than any drug or remedy humans have ever invented - in fact, the single biggest medical innovation of all time - the vaccine - isn't actually a medicine at all, it is just a way to teach the body's natural immune system how to do its job a little better.

Certainly if you have cancer, or a severe bacterial infection, a compound fracture, diabetes or appendicitis, modern health care can mean the difference between loss of life or limb, and a full recovery.  But for the vast majority of ailments, both physical injury and pathogen, the best possible thing you can do is support your own general health: stay physically fit (balance intense exercise with sufficient rest and recovery), get enough nutrients and calories (but not too many calories), get enough sleep (every night!), and keep emotional stress to a minimum (which, believe it or not, has very little to do with your life circumstances.  It is almost entirely about your outlook).
These four lifestyle choices: exercise, nutrition, sleep, and optimism, correlate far more strongly to overall health than access to any particular form of health care or treatment, more even than access to any form of healthcare at all.

Because of the evolutionary process, because of living cell's incredible ability to repair damage to itself and destroy infections,

Almost every medical problem will heal itself, all on its own.


 With no treatment, just time and nutrition and rest.

And that means that if you take or do any form of "treatment" long enough, it will seem like it "worked", just because your body was repairing itself all along, and you happened to be doing this other stuff at the same time. You end up better, so everyone assumes they got better because of the treatment.  But you probably would have gotten better anyway.  

That is without even considering the placebo effect.

The human body generally fights off a cold in barely over a week, with no drugs or remedy of any kind.

Say you start feeling symptoms a day or two after you first catch it, the next day you start taking a remedy, and then a couple days later the cold is mostly subsided.  People will almost universally assume that the remedy cured the cold, but it didn't do anything.  There is no substance that can reduce the length of a cold. Anything which reduces symptoms (like a fever reducer) will increase the length of the cold, because the medicine isn't fighting the virus, it is fighting your body's natural response to the virus.

But as a single individual there is no way for you to test taking the remedy and not taking it side-by-side to see which gets you better faster.  You have to either take it or not take it.

This is the whole reason clinical trials and studies were invented in the first place. 

And then people figured out that just being in the trial made people get better, because of the placebo effect, and they had to introduce the double blind placebo trial.

Placebos genuinely make people feel better - and that has much more significance than you realize.  It affects you more than you ever realized, and more than you want to admit.  This is why you got my first question, in the opening line to this essay, wrong. You can not know a medicine, or any medical procedure is working because you "feel" it working, because there is no possible way you can control for the placebo effect in your own personal first hand experience. 

It is not humanly possible for anyone to answer "yes" to that question and be right. Read about it at the link below:

Investigation into the placebo effect

I know, you already know about placebos.
Remember that question I opened this blog post with?

"Have you ever taken a drug that you know for sure works, because you could feel the difference it made?"

If you answered "yes" to that question (and admit it, you did), then you don't really understand the significance of the placebo effect.  You may understand, intellectually, that it happens, but there is a disconnect, a cognitive dissonance, where you think you are an exception.  You think you can feel the difference a drug or physical therapy makes objectively. Placebos seem like a fascinating phenomenon that affects other people.  Millions and millions of other people.

Even if you accept that, for example, you don't always know all of your subconscious motivations for your behavior, everyone thinks they can "know" their own body objectively.

But believing that is just as ridiculous as thinking you can "tell" from the moment of conception that you are pregnant (it takes between one and two weeks for the egg to implant, so there is no change to feel before then), or that you can "feel" when somebody is looking at you, (you can't).

You, my dear reader, are a human.  You have all the limitations that all humans have.

There is so much more to the placebo effect than we normally think about.  The placebo effect is deep.  Fascinating.  And extremely important, extremely relevant to daily life as living creatures.  I would highly recommend reading  some more about it - for example this and this and this.  It should be required for any person who has a body.

You would think every single medical professional, in any field, would know this stuff, but the unfortunate reality is that doctors aren't remotely scientists in any sense of the word.  Not just the "alternative" folk, but regular, med school graduating, AMA member, licensed professional doctors.  They are largely guessing.  They don't keep up on research.  They get influenced by the pharmaceutical and medical device industries, and by what school they happened to go to and what their co-workers happen to beileve:

http://www.utne.com/science-and-technology/a-study-a-day-keeps-the-doctor-away.aspx

Read it.  It's scary stuff. You should not trust your doctor.  Doctors are just people, and they make all the same normal mistakes that all humans make.  Question them.  Get a second opinion, from a doctor in a totally different field.  Get a third opinion.  Take advantage of the age of the internet and do some research on your own.  Try to prove them wrong, even if you suspect they are right.  Every good scientist sets out to prove her own hypothesis wrong before publishing, because it's in searching for contrary data that confirmation bias is undermined.  Its easy to find what you are looking for, but finding what you are looking for is poor evidence that you are actually right.  Search for what you aren't looking for.

We tend to assume, maybe because of all the training they get, maybe because of the white coats, that doctors are like scientists for health, but they aren't.

If a molecular biologist is like an engineer, a doctor is like a mechanic.
The engineer designs brand new inventions, and to do that they have to have extensive understanding of materials science, newtonian physics, mechanics, and advanced mathematics.  The mechanic only needs to understand enough mechanics to figure out how the thing the engineer designed is supposed to work, in order to fix it when it breaks.  It is an important job (its MY job!), but you shouldn't assume a mechanic understands all of the how and why of which materials were chosen or why they were put together just so.  

Similarly, while science at large has figured out a myriad of metabolic pathways, enzymatic processes, and all of the other stuff going on behind the scenes within the human body, doctors tend to only scratch the surface enough to diagnose a few particular problems, and suggest possible ways to help correct them.

A doctor is a mechanic for the body.

Like mechanics, they often seem to believe they know more than they really do, diagnose based on "intuition", and frequently stray from their specialty (or are quick to see every illness as somehow related to their particular specialty).  Given how complex life is, any doctor who finds a simple cause and effect relationship should be at least a little suspect. Given how much there is left for science to learn about how everything works, the more confident a doctor is, the less you should trust them.  Think of them more like weather forecasters - they have more training and equipment than you, so they can give you a better prediction than you can make by guessing, but everything they say has a percentage likelihood of being wrong.  The best doctors know this, and they will be upfront with you about it.  Never discount a medical professional for saying "I don't know".  That is usually the most honest possible answer, and when it comes to your health, an ambiguous truth will at least not do as much damage as a confident mistake can.

All that stuff makes people turn away from modern medicine, and to "alternative" medicine, but that's even worse.  Much much worse.  By definition, alternative medicine is anything which has been already proven in tests to NOT work.

People are drawn to the easy answers, to the alternative health care provider's sense of certainty, to their rejection of "artificial" pharmaceuticals in favor of "natural" treatments - never mind that drugs are derived of naturally occurring compounds, that plenty of herbs are bad for you or even deadly, that cooking food is a process of chemistry, or that the animal body is the biggest, most complex chemical factory that has ever existed.

Some people suggest never eating anything with an ingredient list you don't recognize and can't pronounce.
You want to see a list of scary looking chemicals?

• oligosaccharides
  pantothenic acid
  selenium
  manganese
  lipoprotein lipase
  inactivated alkaline phosphatase
  lactoperoxidase
  C16:0 ß-hydroxy fatty acids
  conjugated linoleic acid*
  phosphorus
  α-lactalbumin
  blood serum albumin
  transferrin
  high proline micelle
  methionine
  cholin
  galactose
  cerebrosides

Gross, huh?  You would never want to eat that weird crap.  Probably something Pfizer created, or Monsanto maybe.

Nope.

Those are all chemicals that are naturally present in milk.

*(which is a TRANSfat omg!!!!!!!! - but wait, aren't transfats all man-made and added by the evil food industry????  What's that?  Some transfats are naturally occurring? How can that be, when everything natural is good and healthy, and all transfats are created by evil corporations??)

Chemicals.
A chemical is anything that is made of matter.  In other words, everything.  Everything you eat and drink is made of chemicals.  You are made of chemicals.  Everything you can see or touch or smell is made of chemicals. Nothing exists that isn't chemicals.  This is not just semantics.  When ever anyone says anything about "chemicals" meaning something "unnatural" or toxic or synthetic or whatever, its coming from ignorance of science.

What is the real difference between a drug made in a factory by a pharmaceutical company and an "all natural" remedy? There are laws requiring the drug company to extensively test their product for effectiveness and side-effects before they are allowed to sell it, while anything not officially classified as a drug has no regulations and  no testing standards.

So far I've listed a bunch of reasons why people might be even more prone to accept superstition in the realm of health care than any other area, but I have found, when discussing this with people in the past, that people are particularly resistant to hearing contradictory evidence to their medical treatments, not just intellectually, but emotionally.

I think, beyond just the normal ways the human mind is always irrational, there are a couple other specific reasons why this is a sticky one:

 - Personal relationships.
This seems to be one of the biggest reasons that alternative medicine is still so popular, despite being proven not to work over and over again.  Its not just that everyone is superstitious.  It's that mainstream medicine has been so totally enveloped by capitalism that doctors don't have time to treat their patients like people.  Which makes people prefer to gravitate to those who actually do treat them like people. 
Compounded by the fact that such a huge amount of physical illness really is closely tied in with the mental and emotional (up to 90% of all doctor visits are for "conditions" caused by stress); sometimes the alternative practitioner really does get better results - just not because of their actual treatments. 
The results are  despite the treatments; they are because of the emotional connection they build with the patient.  

So, of course, when someone challenges the validity of the alternative "treatment", the patient will naturally immediately feel this is an attack on their own personal doctor.  Their own personal doctor is a good person!  S/he is honest and caring and hard working, s/he has a real medical degree and 3 decades of experience and has helped 1000s of people! 
Questioning their belief is seen as a character attack. Even though the same person might dispute a particular religion even while they have close personal friends or relatives who hold that religion, or dispute an economic theory without feeling it is an attack on all who believe it.

It is not a statement on the integrity of any individual.  Doctors are human.  Humans make mistakes. Alternative medicine practitioners believe wholeheartedly, they get invested in their own mistakes and suffer confirmation bias and the backfire effect and all the rest.  That doesn't make them bad people.  It doesn't make them all con men and tricksters.  Most, certainly the vast majority, are totally sincere.  Just like the billions of people who believe in a particular religion, the strength of conviction doesn't mean they are right.

 - People always hate to be mistaken, but they especially feel bad about it if they have spent significant time or money, investing in something that turns out to be wrong.
Nobody likes to feel stupid, and we especially hate feeling like suckers.  So, instead of correcting the view later once we have more information, we usually ignore the new information, or look for a way to justify the old belief.

 - If it feels like it's working, then most people feel it's safer to just keep doing it than to stop, and risk relapse.
If you read some of the links on placebo, there are lots of examples of people asking to continue their treatment even after they are told it was fake!  They KNEW the drug wasn't helping, but they were afraid to change the conditions that led to feeling better.  It's an extreme example of the natural human faulty reasoning of post hoc ergo prompter hoc which is the basis of almost all forms of superstition.  If humans do that even when they know for sure the drug was a fake, it shouldn't be much of a surprise that people will cling to treatments that, as far as they know, might actually be working - even if that "might" is just based on not knowing enough biology and related science to objectively evaluate it.

Between the fact that the body heals itself regardless of what we do the vast majority of the time, and the fact that the placebo effect makes us feel better if we do or take anything that we are told will help, it is no wonder that every form of alternative healing seems to work to those who seek it out.

The treatments always seem to "work" in that the person gets better - or, at least, feels better temporarily.

Of course, there is a huge difference between feeling better for a little while, and actually getting better.  
This is when it really gets me - when the "treatment" isn't even supposedly a cure, when the "treatment" is supposed to continue indefinitely.   I have no numbers to back this up, so maybe I'm wrong, but from personal observation, alternative health care providers seem to much more frequently prescribe "treatments" to patients which are supposed to be regular, and for a lifetime.

I think most of the medical folk who prescribe such things are sincere, but it is certainly convenient that their cures require a lifelong prescription - and the accompanying lifetime of payments.

This seems to be particularly prevalent among the various structuralists, and in particular following any large - but one-time - injury.  Remember when I pointed out that the entire body renews itself regularly?  Different bones heal at different rates, anywhere from 3 weeks to 3 months. Torn muscles, tendons, and ligaments, heal within 2 months, and even the most severe damage, that requiring surgery to reattach something torn all the way through, heals within 4 months.  If a person is being treated for an injury that occurred years ago, they really aren't being treated for that injury at all.  That injury has long since healed on its own.

Its important to keep in mind - even with a scientifically validated drug or surgery or other procedure, nothing that medical care can do can actually heal you.  Only the body can do that.  The best treatments serve to facilitate that healing, to remove any obstacles to healing.  Health is the body's default natural state.

I am beginning to suspect that in a lot of these cases the "cure" itself is actually prolonging the problem.

Sometimes this is by interfering with the body's natural self-healing. Sometimes they may make things worse by direct action - unintended drug interactions and side effects, or physical therapies that damage tissues.

In some cases the treatment may prolong injury in the same way that cold remedies do: they make the patient feel better (temporarily), and with their pain masked, they don't rest as much as they need to in order to allow the body to heal.  Contrariwise, oftentimes a person will be told to avoid use of a body part for so long that the muscles and tendons get weak and inflexible, which in turn makes them more prone to future injury.
The most obvious example of this is back injuries.  Someone who has ever strained their back tries to avoid ever doing anything that might stress it, and consequently the muscles bones tendons and ligaments of the lower core atrophy and get weaker and weaker, to the point where they are at much higher risk of injury than they would have been if they had taken the opposite approach, and engaged in a (careful, gradual) consistent program of progressive-load weight-bearing resistance training, and higher risk even then if they had just maintained normal everyday activities.


Most of the time the treatment itself is probably neutral, but the false diagnoses produces a "nocebo effect". They tell you something is wrong with you, they tell you to expect certain symptoms (unless you let them heal you), and you experience what you are expecting. They tell you the symptoms will recur within a certain amount of time, and because you are expecting it, you feel it. The nocebo effect is equally as strong as the placebo effect. You may recall from some of the links above how being told to expect certain negative side effects caused them intensely in patients of both fake drugs and fake acupuncture.

Anytime a health care provider tells you that the problem is something fundamentally wrong with you, or a natural tendency to go out of alignment, out of balance, to absorb negative energy, to build up toxins that need cleansing, whatever it is, the fact of having been told that will make you far more prone to feeling negative symptoms in the future - or to interpret minor unrelated things as being that sign you were waiting for - and that feels like it validates what you were told, and justifies giving them some more money (and time) to let them "heal" you.

I don't think the practitioner does this deliberately, any more than bloodletters and other dark age doctors who killed more of their patients than they helped did it deliberately.   But as a patient, we all owe it to ourselves not to put blind faith in an industry or ideology which has gotten so much wrong all throughout history, and whose track record even today is - debatable. At best.

I'm not trying to tell anyone else what to do or think or believe. 

I just feel a responsibility to share information I have had the privilege of having access to.

I can say, for myself, that I once was a fan of alternative medicine myself, but today I am skeptical of all forms of medicine. Before I take any medical advice, I need to know for myself the clinical trials that have been involved, the efficacy rate, the side-effects and complications, I need some references to independent research, (independent of anyone who is in anyway in the profit chain), and perhaps most of all, I have to understand the process, the cause and effect - how it works, and why.  Lucky for me - for all of us - we happen to live in an age where all of this information is available, for free, from the comfort of home.  For something which has such a profound impact on quality of life, it should be worth a few hours of research.

I think understanding the world at all requires a healthy level of skepticism, but most especially when it comes to health care.  For one thing, the stakes are particularly high.  For another, throughout the history of civilization, medical practice has gotten things wrong much more often than it has gotten them right.
Look at the 4 humors, or bloodletting, or leeches, exorcisms, lobotomies, and the hundreds of downright silly superstitions that nearly every culture has had at some point - so much stuff that we look back on now and think "what in the hell could those people possibly have been thinking?"

And yet, we are so filled with hubris that we never stop to think how, 100 years from now people will look back on us today and think the same thing.

You trust yourself WAY too much

Think about all the stuff you know, on all the millions of topics there are to know stuff about - numbers, names, relationships, science, history, skills, where you left your keys...
Now think about how many times in your life you have been mistaken about something you had been pretty sure of.

Of all the stuff you "know" right now, a fair percentage of it is wrong.

For some strange reason, nobody seems to notice this, and everyone goes on being sure about all manner of things - frequently including things that there is no possible way they could know for sure.

We (humans) have figured out a fair bit about our own minds.
Our awareness, perception, and recall are all very, very bad; yet we almost all almost always remain confident that our own perception accurately portrays the world outside our heads, that our memories accurately reflect what actually happened.

But you don't have to take my word for it.


The following 3 documentaries are really fun. They are interactive - if you have any doubt about your own limitations, if you don't doubt your self as much as you should - these videos should cure you of that, and grant you some humility.
And they do it in a totally entertaining way.

Watch 'em!!!

(Embedding isn't working, blogger won't upload, and Nat Geo won't allow it on youtube, so you will have to click on the links to watch)

  National Geographic: Test Your Brain Episode 1 - Pay Attention

  National Geographic: Test Your Brain Episode 2 - Perception

  National Geographic: Test Your Brain Episode 3 - Memory



No, I'm serious, click, watch.



Its free!
They are each 45 minutes long, but what you learn from it will make your life better forever.
They will help you make smarter decisions.

And aside from all that, it's filled with tricky games and puzzles, magic tricks (which they then explain) and tests, and if you don't enjoy it, I offer you a rock solid no-questions-asked, double-your-money-back-guarantee.

If you make it to the 5 minute mark without getting sucked in, well... I just don't know what's wrong with you.

 You may not have an entire 2 and a half hours right now, but do come back and watch the other two as soon as you have a chance to give it your undivided attention.

 And when you finish, take some time to reflect on what it all implies.



Its fun and interesting, but it is really one of the most profound realizations a human can have, to fully internalize this information, to accept how this affects us literally every day, to acknowledge what it implies about everything we think we know.

 As all the games and puzzles in the 3 videos showed you - you, reading these words right now - are not an exception.

 It isn't just some interesting psychological study, weird guys in labs coats doing stuff to dogs and rats which is ethically questionable, or surveys with tricky worded questions taken by college kids.

 This stuff affects you every second of every day, every piece of information you take in is processed by the same brain that failed all the tests in these documentaries.
 Which means you should always be aware that what you remember is not necessarily what actually happened, you should know there was always something going on that you missed, know that every single experience is subject to misperception, and you should question the stuff you are confident about just as much as you question those who disagree with you.

 This is not to say you can never know anything with confidence. It just means that personal experience should not outweigh better evidence. Maybe you saw something that looked like a ghost once, but given how imperfect our awareness, perception, and memory is, the more objective evidence against it should outweigh your personal experience.

Get over your ego.

You aren't always right.

 Even things you are 100% certain about, sometimes turn out to be wrong.

 Maybe you should be 100% certain less often.

This isn't an insult to you personally, it is just the nature of the human brain. We weren't optimized for our modern world, nor, for that matter, for understanding the world and getting to underlying truth's. We were optimized for survival on the savanna, and sometimes superstition leads to better chances at survival than careful objective analysis. Our world today is a million times more complex than eat or be eaten though, so it is in our own best interests to learn what our brain's limitations are, so that we can learn to compensate for them.

So, who do we trust, if we can't even trust our own senses? Not somebody else, that's for sure. Somebody else makes all the exact same mistakes as we make, but with the added disadvantage that they haven't seen those videos, they haven't been to the You Are Not So Smart blog or heard the podcast

   

and so their misinformed opinions don't even have the chance to compensate for the human mind's natural errors, because they aren't aware of them.

Enter Science!

Science is not guys in lab coats with fancy degrees and expensive equipment.
Science is just a method for checking if a particular idea is right or not, as objectively as possible.
Its a way to compensate for all the limitations of the brain that those documentaries I linked to just taught us about.
No one person can make a scientific proclamation and have it actually be science - it is crowd sourced, anyone can check, even up to and including you, whether the things it suggests actually pan out under testing and double testing. That's what makes it more reliable than personal experience, or even the collected opinions of thousands of people.

But I won't go into that in too much detail, because I already have, quite extensively, here:

  Science!


  http://biodieselhauling.blogspot.com/2013/05/science.html

Refuting the "Big Car = Safe" Myth

It is a universally known "fact" that the bigger the vehicle you drive, the safer you are.

Even those who buy small vehicles know this, they just feel that the increase in risk is small, and the benefits to parking, mileage, and cost are worth it.

Like many other universally known things, it just happens to be wrong.

This is extremely easy to prove:  just look at the actual crash statistics, compiled by vehicle weight:

(the NHTSA website is down, if / when it is restored, I'll post links to the original data)

At first glance this may appear to support the myth: Large vans are at the bottom, with the least crashes, and compact cars are at the top, with the most.

But look a little closer:

Subcompact cars are SAFER than compact cars.  They are even safer than small pickup trucks.

But subcompact cars weight LESS than small pick up trucks, as well as less than compacts.

Skip down a couple more lines: Full size cars are SAFER than full-size SUVs and standard pick-ups, even though on average they weigh substantially less.

But wait, there's more!  Midsize cars actually rank as safer than all sizes of truck, all sizes of SUV, and even safer than full-size cars!

So, if you were rationalizing that SUVs and trucks are only more dangerous than large cars due to roll-over risk, you still have to explain why midsize cars have fewer fatalities than large cars.

Here is similar data, with different presentation: a chart of risk relative to average (100=average) of several vehicle types

      Vehicle Class                Avg. Weight      Relative Fatality Risk

Subcompact (high-risk)             2,000lbs                    143

Sports Cars                              3,200lbs                    142

Compact Pick-ups                    3,500lbs                    123

1/2-ton pick-ups                       4,300lbs                    105

3/4-ton pick-ups                       5,400lbs                    101

1-ton pick-ups                          7,000lbs                    100

Compact cars                           2,500lbs                     96

Subcompact (low risk)              2,000lbs                     85

Truck based SUV                     5,400lbs                     82

Large Cars                               4,400lbs                     75

Mid Size Cars                          3,200lbs                     74

Full-size Vans                          5,000lbs                      52

Cross-over SUVs                    3,500lbs                      48

Minivans                                  4,500lbs                      40

Import Luxury cars                   4,000lbs                     35

http://energy.lbl.gov/ea/teepa/pdf/aps-ppt-wenzel.pdf

This data is from a different range of years, and formatted differently, so there isn't 100% agreement, but it shows the same trend - or rather, lack-there-of: there is absolutely no direct correlation between vehicle weight and risk of fatality.

Even within a single body type: cross-over SUVs weigh less than truck-based, yet have lower fatality rates.

Minivans weigh less than full-size vans, yet have lower fatality rates.

Mid-size cars weigh less than full-size, yet have lower fatality rates.

Notice that the authors of this study divided sub-compacts into two categories, because the range of data points was so wide.  Were they lumped together (as is often the case), the really bad ones would seemingly drag the safer ones down with them, making the entire category look bad, when its really a specific set of them. 
The lower risk subcompacts were found in real world crash statistics to have LOWER FATALITY RATES THAN TRUCKS OF ALL SIZES, up to and including the largest category of "passenger" truck, the 1-ton; which, despite the name, weigh in the range of 3-4 tons, up to 4 times as much as the sub-compacts that are safer than them.

Here is yet more data, in case you like graphs better than charts:

This graph is counting fatalities per crash, so its already assuming a crash occurs:

(from: http://www-nrd.nhtsa.dot.gov/Pubs/808570.pdf )

And this one, specifically for the type of crash where weight matters most: frontal collision with another vehicle

(from: http://energy.lbl.gov/ea/teepa/pdf/aps-ppt-wenzel.pdf )

You can download the original full reports if you want all the details, but the important thing to take away from these you can see at a glance: the dots are all over the place.  There is no trend for the lighter cars to have more fatalities, whether you look at per vehicle, per accident, or even per accident involving another car.

This should be enough.

Case closed.

The data is clear: heavier cars aren't safer.

But of course it isn't so simple.  Not because the facts are complicated, but because the human mind is complicated.

We aren't optimized to think in terms of statistics, we are optimized to think in anecdote.

And so when the most well-intentioned people attempt to study auto safety in order to improve it, even professional researchers fall victim to the same faulty reasoning and assumptions as the general public, generalizing things like "common sense" and "crash test data" to actual real-world risk.

And so, despite what the actual information about the real world clearly shows, even the Insurance Institute for Highway Safety (IIHS) claims

"All other things being equal, occupants in a bigger, heavier vehicle are better protected than those in a smaller, lighter vehicle." 

That sentence stands alone, as though it were universally factually accurate... but then soon after it is qualified by the important distinction that makes it accurate:

"Weight comes into play in a collision involving two vehicles. The bigger vehicle will push the lighter one backward during the impact. As a result, there will be less force on the occupants of the heavier vehicle and more on the people in the lighter vehicle."

(Then, to demonstrate this, they have a graph not of vehicle weight, but of vehicle size relative to risk (the bigger in size, the bigger the crumple zone))

This second sentence is actuate, and it is where all the confusion comes from.

The qualifier is nearly always neglected, but it absolutely completely 100% changes the context and meaning of the entire idea.

A heavier car is safer IN A HEAD-ON COLLISION WITH ANOTHER VEHICLE.

Here's the thing about that, though:

Most car accidents aren't head-on collisions with other vehicles.

In fact, the majority of them aren't.

In fact, the vast majority of them aren't.

Head-on collisions only make up 2% of all car crashes!!

(They make up 9% of fatalities, so even limiting to severe accidents, they are relatively insignificant - 89% of fatal accidents are not head-on)

In comparison, rear-end accidents make of 32% of all crashes.

Collision with fixed objects make up 33.5% of all crashes.

Rollovers accounts for 10%

In a collision with a solid object, like a concrete barrier or a tree, the total deceleration will be the same whether you are in a mini car or a land yacht: essentially whatever speed you were going to zero instantly.

In a rear-end accident, your car gets pushed forward, and instead of jerk, you just get acceleration.  The energy is absorbed by the movement of your vehicle.  You may get whiplash, but you don't get dead.

Consider the most extreme scenario: you are in a passenger car, and you get hit from behind by a 80,000 lbs semi-truck.

As long as you don't aren't pushed into the car ahead of you and get smushed (which you won't, if you leave proper following distances) the fatality rate is only 0.34%

Even if you get hit from behind by a vehicle that weighs 40 tons, about 20 times more than your car, you have a 9,966 in 10,000 chance of survival.

http://www.fmcsa.dot.gov/facts-research/research-technology/analysis/rear-end-crashes.htm

Least you think that's only because rear-end collisions only happen at low speed, when its the cars hitting the semi's, the fatality rate is about 4 times higher - for the car, running into the semi is almost as bad as running into a brick wall.  When its the semi hitting the car, the car gets pushed forward, the movement absorbs the kinetic injury, and everyone is happy and smiling.

This shows two things: 1) Rear-end accidents are rarely fatal regardless of size differential, and 2) the direction an impact comes from absolutely does change whether weight matters.

If the mass differential of a semi-truck - 80,000lbs - vs a car - 4000lbs - is so insignificant, what do you think the impact of mass is on a rear-end collision between a 2000lb car and a 4000lb car?  The answer is none.

In a side impact the situation is similar: the impact force in tangential to your momentum, and so the amount of momentum you have is irrelevant.  Simple thought experiment: whether you are speeding or at a stand still, getting broad-sided will impact you equally hard.  Momentum doesn't matter.  But then why would mass? 

In fact the IIHS themselves - the very people who state categorically on their consumer website that "heavy cars are safer", say explicitly elsewhere on their consumer site:

"Unlike frontal crash test ratings, side ratings can be compared across vehicle type and weight categories. This is because the kinetic energy involved in the side test depends on the weight and speed of the moving barrier, which are the same in every test."

In other words, in a side-impact crash, your car's weight makes absolutely no difference.

But side-impacts make up 23% of crashes, and 18% of fatalities (compared to 2% and 9% for frontal crashes), so this rather undermines their own claim about the impact of weight.

In roll-overs, too, weight does nothing to improve your chances.

Fixed objects, rear-ends, side-impacts, roll overs - in 98% of all crashes, extra weight does literally nothing to protect you.

How much sense does it make that simulated two-vehicle frontal impact tests are the standard for "crash testing", when it is one of the least common types of crash?

So what about those few times you are actually on a high-speed undivided back-country highway, and some drunk crosses over the double yellow lines?

Even then, weight is not the most important factor.

KE=½ mass X velocity²
Kinetic Energy= (1/2 of mass) X (Speed squared)

The impact of your relative speeds is squared (multiplied by itself).  The impact of weight is divided by two.  The speed you are going is overwhelmingly more important than how heavy your car is.

Ok, so...

If there is all this evidence that weight really doesn't matter that much to safety, then why does everyone - even people who's entire job is analyzing car crashes, keep repeating the same myth?

Perhaps for the same reason you, the reader, are still not convinced.

Because, on a purely intuitive level, this belief feels like it makes sense.

It is an extension of the (equally false) assumption that being in a car is safer than being on a motorcycle: "because the steel cage protects you".

How could you not feel safer in a nice strong cage than exposed to the world?

Here's the thing about that though: a steel cage does not "absorb" the crash energy.  It TRANSMITS it.  It transmits it through the steel structure of itself, and on to you.  The stronger it is, the more effectively that force is transmitted.  Think about the "Newton's cradle" desk toy:

5 steel balls on strings, the first one is given a swing, and when it hits the rest, the force travels right though them to the last one.  The last one takes just as much impact as it would if the first hit it directly, because the others are solid, and the force just goes right through them.  It doesn't even matter that the 3 in the center have a combined mass of 3 times as much as the two on the ends.  The one on the end is in no way "protected" by them, as they don't "absorb" any of the force, they simply transmit it.

Because it feels right intuitively, and because it is repeated as a given almost universally, no amount of text is going to help people understand the error of this belief.

They say a picture is worth 1000 words, so a moving picture has got to be worth even more:

Here is perhaps a less abstract way to think of it:

Imagine that, instead of being inside a car, you are standing in front of one that is parked.  It is parked in neutral, with no parking brake on, but it is on perfectly flat ground, so it doesn't move.  You are just standing there, minding your own business, when a truck comes along and runs into the car.  Imagine how this will affect you.  Is the mass of the car going to somehow magically absorb the impact energy and make it go away?  No, of course not, its going to start moving forward.  And then its going to hit you, with close to as much force as if the truck had just hit you directly.

But if the mass of the car doesn't do anything to protect you when it is fully between the truck and your body, why would it do anymore to protect you if you are inside of it?

The answer is that it doesn't.  Like the Newton's cradle, the steel frame of a car simply transmits the force of any impacts on to you.

This is why modern cars have crumple zones.  They are deliberately, by design, weaker than the solid steel tanks of the past. Of course they aren't arbitrarily weaker - the human containing cabin is made stiff, while the front and rear are made soft on purpose so they take the impact energy.

Take, for example, this crash test between an old tank of a car and its modern descendant (which, incidentally, is about 200lbs lighter)

http://youtu.be/mJ5PcWziXT0

But even with crumple zones, having a steel cage doesn't do much to keep you safe on its own.  Another major difference between the old and new cars is seat belts and airbags.

Seatbelts and airbags don't actually protect you from the car that crashes into you.  They protect you from you hitting the inside of your own car.  The entire reason for having seat belts and airbags is to protect you FROM the steel cage you are riding in.

Again, this may be easier to fully grasp in cartoon form:

Given that a car has seatbelts and airbags (and that you actually use them) to protect you from the steel and glass of your own car, having strategically placed crumple zones outside of a stronger solid frame around the passenger compartment creates infinitely more safety in a crash than increasing mass, as shown in the crash test above, where the slightly lighter car completely obliterates the poor crash test dummy in the older car.

But even with two misunderstandings corrected, we are still looking at the entire question the entirely wrong way!

Because we are still thinking in terms of how survivable the passenger compartment of our car is, in the event of a severe crash.

This means we are treating severe crashes as though they are inevitable. In the real world, of course, since about 98% of accidents are caused by human error, its fair to say that nearly all accidents are avoidable.  They shouldn't even be called "accidents", because it makes it sound like its just some random thing that happens.  Really the VAST majority of auto collisions are due directly to negligence, on the part of one or both drivers.  If everyone drove below the speed limit, left large following gaps, refrained from alcohol and drugs, avoided all electronic distractions, and focused on driving safely, the fatal accident rate would drop from the single largest cause of accidental death to fairly negligible.  Combined with proper maintenance, it would be barely above zero.

So if severe accidents aren't actually inevitable, maybe instead of just focusing on likelihood of surviving an accident, it would make more sense to factor in the risk of getting into an accident in the first place.
Ask yourself: Which would you rather do, crash and survive, or not crash in the first place?

So then you have to wonder, what factors might reduce the chances of getting into a crash?

Well, imagie you are going 60MPH in a 5,500lb Ford Expedition on a rural highway, and a truck pulls out from a cross street 140 feet ahead of you. If you instantly apply maximum brakes (ignoring reaction time, which is the same regardless of vehicle) you are going to slam into it at roughly 35mph, the same speed that crash tests are conducted at, and enough to cause very serious injury.

If, however, you were driving the 3000lb Ford Focus, and were in the exact same situation, you would be able to come to a full stop a full 26 feet in front of the truck.

All other things being equal, smaller cars tend to have better braking distances, more maneuverability, and frequently better 360 degree roadway visibility for the driver compared to a larger vehicle.

Comparing trucks and SUVs to cars, due to their higher clearance, are far more likely to roll over, an event with a higher risk of fatality than most accident types.
In addition to all those factors making them capable of avoiding accidents better, the lack of (false) perception of safety may encourage drivers of small cars to take fewer stupid risks (which are, ultimately, the cause of almost all accidents).  The very fact that people feel safe in big vehicles make them do more stupid stuff, like speeding and reckless driving, than the drivers of smaller vehicles.  It's called risk compensation - and its counter-productive when the assessment of risk is completely wrong.

Extra mass only comes into play in a helpful way in 2% of crashes.  In the other 98% it is neutral at best - but in some percent, it is almost certainly a contributing factor - not only because of worse braking distance and handling, but also by encouraging drivers to drive worse.  In that last 2% mass helps, but not nearly as much as people assume.

This myth has been a significant driver of the trend of average passenger vehicles on the road to get heavier and heavier, as consumers pick cars that feel "safe", fueled by crash tests ratings being treated interchangeably with "safety", and official proclamations by official agencies.  One thing that is shown consistently in the statistics is that heavier cars and trucks are definitely much more deadly on average to the people they hit.  So the net effect is more traffic fatalities overall.   This is more than just counterproductive.  It is tragic.

Every time you here this myth repeated, think about the cartoons above.  Think about the graphs and charts. 
And don't let the myth influence your next car purchase.