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Let's get this out of the way first...

In the realm of science, a theory is an idea that is so strongly supported by data and prediction that it might as well be called a fact. But in common conversation among non-scientists, "theory" means almost the opposite. To the non-scientist, calling something a theory means you don't have enough data to confirm it.

I'll be talking about the scientific definition of a theory in this post. And I have one question that I have seen asked many times (unsuccessfully) on the Internet: How often are scientific theories overturned in favor of new and better theories?

I assume Creationists are the ones usually asking the question. And if history is our guide, the comments on this blog will focus on that one area and destroy the value of this blog post. I'm hoping we can ignore evolution and creationism and climate change for one day and just ask the following question: How often does a scientific theory get discarded or replaced with a better one?

I don't think there's a good answer to my question, for lots of reasons.

For starters, I doubt anyone has been keeping a stat on overturned theories. And I don't think it's fair to compare theories from a hundred years ago to theories created today because our ability to collect confirming data today is better than it used to be. I would expect that a theory created recently would be more likely to stand than one created last century.

Still, it has always been true that the stuff we believe today looks way smarter than the dumbass things our grandparents believed. Why wouldn't that be just as true for our future great-grandkids looking back at our primitive beliefs? Some humility is always called for.

Science requires credibility to be useful. And that's a problem. The non-scientist asks "What is your success rate?" and gets no useful answer. Scientists, as it turns out, are terrible at marketing. About 90% of my exposure to science involves media reports that get correlation and causation confused. As a result of that exposure, the more I hear about science, the less credible it feels.

To make matters worse, I have a jaded Dilbert mindset about every industry. Unless science is different from all other human endeavors, 10% of scientists are honest and amazing and doing important science while the other 90% are like Dilbert's worthless co-workers. So when I hear that 98% of scientists are on the same side of an issue, I wonder how many unreliable people you have to add together to get an opinion you can trust.

I don't think I'm alone in my views. I'll bet that if you did a poll you'd find that scientists believe theories are fairly dependable and useful whereas the average non-scientist believes that everything we think we know today eventually gets disproved. Part of the problem is that scientists are looking at utility and non-scientists are looking at "truth" which is a fuzzy and overrated concept.

In every other field, your track record of success determines your credibility. Personally, I have no idea what the track record of science is. All I know are anecdotes about wonderful successes and notable mistakes. I don't even have a general sense of whether scientific theories have usually held up over time or not.

So when scientists say a particular theory is backed by the majority of scientists, how much weight should I put on that? Is that a situation in which I can depend on the scientists to be right 95% of the time or 5%? What's the track record?

Note to the Bearded Taint's Worshippers: Evolution is a scientific fact. Climate change is a scientific fact. When you quote me out of context - and you will - this is the paragraph you want to leave out to justify your confused outrage.


Scott Adams

Co-founder of CalendarTree.com

Author of a book on success. (Makes a good graduation gift, btw)


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Apr 22, 2014
I'm pretty sure that ALL theories are eventually proven wrong, at least in part. I'd like to know of a scientific theory more than 100 years old that has not been overturned/superseded/modified to fit new knowledge and understanding. If there are none, how about 75 or 50 years.
The truth is that all scientific theories are partially or completely wrong. We are like a colony of resistant bacteria living out our half-second life on a soap bubble and expecting that we have figured everything out.
Apr 20, 2014
I'm a grad student, and I have to agree with you on the 10/90 rule.
I've met some talent, and I've met complete imbeciles.
Apr 17, 2014
It seems to me that when a theory gets overturned, it tends to get replaced by something incrementally better (better being defined as ability to predict future behavior accurately).

For example, an early model of the solar system had the Earth in the middle and everything revolving around it (which is not a ridiculous first model). Then it gets replaced with the Copernican solar system with the sun in the middle and circular orbits. Then Newton came up with his theory of gravity and accurately predicted planetary motion in complex elliptical orbits. Then comes Einstein and the theory of general relativity, which supersedes Newton's theory of gravity.

Each theory was better than the previous, so each was useful but none perfect. It's like the old saying "All models are wrong. Some are useful."
+10 Rank Up Rank Down
Apr 17, 2014
To expand on excellent comments by PeterWhelan and gilknut...

It's astounding what absolutely measurable facts people get wrong. An online dating site I use has a question asking "which is larger, the earth or the sun?" From what I've seen, over half say the earth. What's really crazy, is that it's a 50/50 question, and it's optional! Over half of the women (I don't peruse men's profile's) who chose to answer that question, blew a 50/50. Wow.

On a brighter note, with judgement like that, maybe they'll also decide to date me.
0 Rank Up Rank Down
Apr 17, 2014
I think the answer to you questions depends on what you mean by wrong. My general idea is taht there have only been few times that scientists have been completely wrong as opposed to just being inaccurate. The progress of science is more about accurate ideas replacing inaccurate ones as opposed to wrong ones.
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Apr 17, 2014


If true, how do you and I live together on this earth in cooperative peace?
Apr 17, 2014
Over half the people still think that the sun revolves around the earth. Like this French audience for "Who wants to be a millionaire" https://www.youtube.com/watch?v=SmLwnSXNpFU

Even those who do know the right answer are unable to explain why it is the right answer. It becomes a belief instead of a fact.

I plan to make a video based on http://en.wikipedia.org/wiki/Dialogue_Concerning_the_Two_Chief_World_Systems

I'm enjoying the feeling of imagining that the video goes viral, is seen by billions, translated into all languages. School kids re-enact the play and understand a larger lesson, that what we perceive ain't necessarily so.
Having deeply learned this one lesson, the whole world becomes more understanding and seeks out similar lessons. Such as "Are Iranians/Protestants/corporations/ really the bad guys?" "Can I believe what I see on CNN?" World peace breaks out.
Apr 17, 2014
(Damnit. Clicked the submit button by mistake.)

that there is only one mechanism to induce heritable changes; through mutations in the genes. Now we know that heritable changes can also be transmitted through Epigenetics, which is highly susceptible to your environment and your lifestyle. Meaning that the Neo-Lamarckian idea that individuals shape their progeny through practice (As opposed to Darwinian Selection) is taking root fast.

What this teaches us is to be more careful about our prejudices and leave the science to the scientists and not to popular media. I would not be very surprised that tomorrow we discover that natural selection takes a backseat to epigenetic transmission thus falsifying our most cherished idea in biology.

Apr 17, 2014
Hi Scott.

Just wanted to point out something.

Science is incredibly hard. Just to drive that point home, I will repeat myself Science is Damned hard. Most science done all around the world results in a zero correlation of the hypothesis to the results. Which means that to say something specifically correct is very very difficult.

You might be wondering what makes me emphasize this point so much.

The reason is of course to do with the entire "Popular science" politicization. Don't get me wrong. Popular science is only a good thing when applied where necessary. It serves to motivate children to do science and get into careers that are driven by an otherwise difficult and raw pursuit. But when popular science gets into adult life I start to worry.

Take for instance this "Evolution vs. Creationism" debate. A silly argumentative thing if there was one. Firstly, there is little understanding that Evolution is NOT a precise term. Everything is de facto evolving. Babies grow into men and saplings into trees. That too is evolution i.e. slow change. What most people implicitly mean when they use the word is to refer to the Darwinian variety. Which should immediately make clear to a more observant person is there is more than one kind of evolutionary theory floating around to explain the diversity and commonality we see around us.

This being said, we have only recently started to understand that there is MORE to genes simply the sequence associated with them. in the early last century we believed that
+2 Rank Up Rank Down
Apr 17, 2014
You have to split the problem in 2 different kinds of theories:
-Testable theories
-Untestable theories
For the first one, the track record is in the last century, as you would expect, perfectly good.
The second one is the only issue. If there is no test yet, assume it can be disproved at any point in the near future.
Apr 17, 2014
There's another kink in answering the question: which branch of science?

Things like medical knowledge and psychiatry are changing all the time because we just know so little about the human body. For instance a new knee ligament was found recently. It was predicted by a french guy in the 1800's, but we only recently been able to find it because not everyone has one.

For all the women reading this blog: have you ever had to fight with 15 doctors trying to find the one who actually knew what was going on for something like pain management? Did you have half of them tell you it was just in your head?

Heck, there's this girl up in New England who the DCF ripped from a family because the DCF's doctor thought a diagnosed medical condition she had was just in her head. He was supposedly too busy to read her medical history before deciding to rip her from her family.
Apr 16, 2014
I appreciate gilknut's comment because it describes how the overwhelming amount of "expert" theories are created on just about anything. I've become apathetic, and I generally just don't pay much attention unless a topic is of great importance to me. And when a topic of importance comes up that isn't necessarily scientific, this is when it gets the most frustrating digging through all the crap looking for some truth. Does anyone have any recommendations on how they deal with this?
+2 Rank Up Rank Down
Apr 16, 2014
I really dont understand what you're after with this post. Scientific theories are descriptions of reality that are NEVER 100% accurate, because they are always simplifications (no matter how complicated they are), because reality is too complex for our tiny ape-brains. In that sense a serious scientific theory can not be discarded; it can be replaced by a better one, or it can be refined.
A hypothesis can be refuted, but that's another story.

Are you aiming at something specific?

For arguments sake, let's say that a "track record for scientific theories" CAN be established (which it can not), then how willl a track record of hundreds of thousands of theories will have any relevance for the credibility of one specific theory?

Apr 16, 2014
From my heart and from my hand
why don't people understand
my intention?
Weird Science

(Oingo Boingo)
+7 Rank Up Rank Down
Apr 16, 2014
...And we can add "e n t i t i e s" to the list of curse words, according to your fine blog software.
+31 Rank Up Rank Down
Apr 16, 2014
Interesting questions raised in Scott's post.

Unfortunately, as a journalist in national media for years (note: not the U.S.) I can't be very helpful in answering them. My colleagues and I tend to go the opposite direction.

I've come to know that most people's perception of scientific theories doesn't necessarily have much to do with the actual science or the views held by the rest of the professional community in the relevant field. As with most topics in this world, people in general take to heart which-ever random article(s) or documentary they've personally been exposed to.

Speaking from considerable experience: The general public would have cause for great concern if they knew exactly how science is conveyed by many (not all) major news media !$%*!$%*!

The process often happen eerily like this:

Reporter: - Hey boss? Look at this. This guys claims you can get cancer from licking your cat during high tide. Something for the Saturday edition?
Editor: - Nice work. Is he a doctor or professor or something?
Reporter: - Do you really want to know?
Editor: - Nope. Does he use a lab coat?
Reporter: - I don't think so. It doesn't go well with his tin foil hat.
Editor: - Well, get him into one, and lose the hat. Have it on my desk in an hour.

It only takes one article like that to turn a reader into an "expert" whenever the topic arises. It doesn't matter that the same paper runs a counter story the next day(*) explaining that 457 renowned scientists, using their outdoor voices, called in to say the tin foil guy's "theory" is rubbish. The damage is done.

You might (accurately) claim this is off-topic in its entirety, but in my line of work there's no such thing.

(*that's how we make a living)
+3 Rank Up Rank Down
Apr 15, 2014
OK, so let’s take a hypothetical scenario (it doesn’t matter what it is) in which the associated science has significant implications for public policy.

Let’s also take the following assertions/assumptions regarding the situation in the US as being largely accurate:

- The public’s knowledge base in science and technology is minuscule
- Little emphasis is given to these areas in publicly-funded schools
- The public’s understanding of the scientific method is minimal
- The public’s understanding of science is still largely in thrall to discredited beliefs based on religious dogmas
- Politicians prefer to pander to these beliefs rather than challenge them
- Most people are too lazy/have too little free time/are too stupid or ill-educated (etc.) to put much effort into thinking through the issues on the basis of facts; they prefer to wallow in the certainty they feel from appealing to their own prejudices and preconceptions
- Ignorance of the complexities of an issue never stops anyone from publicly expounding their views about it to anyone they hope will listen
- News media like to promote scientific controversy because it increases revenue; indeed, the more the outliers deviate from the consensus position, the better for the controversy
- An industry of charlatans exists to publish books and/or sell other products that pander to the prejudices and stupidity of the public
- Most scientists are not much focused on providing the public with clear explanations regarding their work or methodology
- Most scientific journalism presented in mainstream venues is mediocre (too unquestioning of the methodology of the science being reported, too willing to regurgitate press releases, too focused on manufacturing culture-bound controversies even when most scientists in the field concerned do not dispute the consensus view)
- Almost all politicians at the state and federal level are vote-catching, cash-hungry opportunists
- Politicians like to use high-profile controversies as vehicles for promoting the financial interests of their paymasters and/or personal agendas
- A lot of revenue or additional costs are at stake for those industries and other stakeholders that would have to respond to changes in public policy, whether promoting or suppressing particular measures
- There is an army of well-paid lobbyists, think-tanks and special-interest groups with ties to particular industries and politicians who are more than willing to distort or invent facts, and downplay or mendaciously contradict any information that does not support their own agenda
- Currently, the atmosphere in state and federal legislatures is either so poisonous or so heavily weighted in one political direction or other that today, almost no bipartisan legislation ever reaches the statute books.

Now explain what grounds there are for optimism that:

a) the scientific basis for the policy in question will be generally understood and carefully considered by:

i) the general public
ii) media organizations
iii) high-profile opinion leaders
iv) policymakers
v) enti_ties in industry and commerce

b) rational public policy will be:

i) debated and drafted
ii) voted into law
iii) sufficiently funded
iv) implemented
+1 Rank Up Rank Down
Apr 15, 2014
The likelihood of any given theory being truly vetted by the entire consensus pool is next to none. So the modern scientific consensus therefore is basing such judgements on apparent authority or marketing or both. One scientist simply does not have time to experiment on every topic or opinion, so they pick the popular views and agree with them - following the herd lest they miss out on a fashion trend. If it's an older theory then you have to take into account confirmation bias and peer pressure. It's not popular to say Einstein was wrong, and it may mean your grant wagon if you try. Consensus therefore is probably is largely formed by grant money and the ability to entertain non scientists of the opposite sex. My advice would be to ignore the consensus marketing, invest time in finding one or two individuals or groups that possess the beliefs and critical thinking skills you admire, then shortcut the rest by agreeing with them on future theories. That's probably more science than the consensus performed and it makes for more interesting table conversation as statistically speaking every now and then you won't be in the herd.
Apr 15, 2014
The main problem with science is that the vast majority of the things that are easily confirmed or disproved via repeatable and controlled experimentation were resolved ages ago. All that's left today are things that involve a lot of guesswork and unclear cause-and-effect relationships. However, the science of repeatable and controlled experimentation gave science such a good reputation among laypeople and reporters that the science of guesswork and unclear cause-and-effect relationships has unjustly inherited the reputation for being always correct.

When I say guesswork and unclear cause-and-effect relationships, I mean things like nutrition (what diets makes you gain or lose weight, note that the thinking on that has changed a lot in the past decade after being "settled" for a while), medicine (what things are and are not risk factors for illnesses that strike the elderly, like heart disease), and yes, global warming (whether carbon dioxide does or does not have an effect on climate that is greater than other factors, whether appreciable long-term warming is or is not actually happening at all, and whether computer climate models are or are not any more reliable than next week's weather forecast).

Quick article quote:
"Imagine a public policy issue that could determine the course of millions of lives. Imagine the science concerning this issue was complex and confusing. Nonetheless, most scientists had reached agreement on certain aspects of it.
And imagine the Washington Post wrote an editorial stating, 'Government agencies must constantly make recommendations on the basis of just this kind of incomplete but suggestive evidence, and there is a consensus on what to do.'
That sounds like the current debate over climate change, doesn’t it? Nope. That editorial is from 1980. The issue was not levels of carbon dioxide in the atmosphere but levels of cholesterol in the diet."
(The article goes on the describe how the theories on diet at the time have since been debunked and replaced.)

Evolution, on the other hand, has a body of taxonomic, fossil, and DNA evidence backing it up that is able to be independently verified by anybody, so creationism is right out in any true scientific sense. About the only place that scientists truthfully admit that their theories are known to be not fully accurate is astronomy, concerning things like dark matter and dark energy. Note that this is one area where the government can't tax or regulate anything, which is probably why there is no rush to accept a "consensus" over proper scientific method.
Apr 15, 2014

[That's a lousy way to define lousy.]

Shrugs. Its how Scott was defining lousy in his post. And one can see his point. Science claims to know how the world will end, but has changed its mind on the matter more than once, so how are we to take it seriously when it says 'Okay, folks, NOW weve got it right!'?

But I still trust it when it comes to making an airplane.
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