I think it would be great to start with a theory that sounds very scientific, but is unfalsifiable, and therefore useless.
Then we modify the theory to include an element that is falisfiable, and the theory becomes much more useful.
For example, we have a new kind of medicine, and it is very good for some people, but when other people take the medicine it kills them. Naturally, we want to know who would be killed by the medicine, and who would be helped by it.
A scientist has a theory. He believes there is a gene that he calls the “Spottiswood gene”. Anyone who has the proper form of the Spottiswood gene will be safe, they can take the medicine freely. But some people have a broken version of the Spottiswood gene, and they die when then they take the medicine. Unfortunately the scientist has no way of detecting the Spottiswood gene, so he can’t tell you whether you have the gene or not.
Now this theory sounds very scientific and it’s got lots of scientific words in it, but it isn’t very useful. The scientist doesn’t know how to detect the gene, so he can’t tell you whether you are going to live or whether you are going to die. He can’t tell you whether it is safe to take the medicine. If you take the pill and you survive, then the scientist will say that you had the working version of the gene. If you take the pill and you die, the scientist will say that you have the broken version of the gene. But he cannot say what will happen to you until after it has already happened, so his theory is useless. He can explain anything, but he can’t make predictions in advance.
Now another scientist has a different theory. She thinks that the medicine is related to eye color. She thinks anyone with blue eyes will die if they take the medicine, and she thinks that anyone with brown eyes will be okay. She’s not sure why this happens, but she plans to do more research and find out. Even if she doesn’t do any more research, her theory is much more useful than than the first scientist’s theory. If she’s right, then blue-eyed people will know that they should avoid the medicine, and brown eyed people will know that they can take the medicine safely. She has made predictions. She predicts that no brown eyed person will die after taking the medicine, and she predicts that no blue eyed person will live.
Of course, the second scientist might be wrong. But the interesting thing is that if she’s wrong, then we can prove that she’s wrong. She predicted that no one with brown eyes will die after taking the medicine, so if lots of people with brown eyes die, then we will know that she’s wrong.
If her theory is wrong, then we should be able to prove that it’s wrong. And then if the results don’t prove that she’s wrong, we accept that she’s probably right. That’s called falsifiability.
But the first scientist doesn’t have falsifiability. We know that even If he’s wrong, we’ll never be able to prove it—and that means we’ll never know if he’s wrong or right. More importantly, even he is right, his theory still wouldn’t do anybody any good.
The first theory is falsifiable as long as you’re willing to let enough people die. Collect blood samples from everyone before they take the medecine. Sequence their full exome and put it on file.
once you have a few thousand dead and a few thousand survivors you should be able to narrow candidates down to a few dozen genes.
Make predictions about who will die out of the next few hundred who take the pill, bam.
Turns out it’s an eye color gene having some weird effect on a vital pathway that the drug is linked to.
Alternatively if it’s not genetic at all, if single members of pairs of twins taking the drug died at rates inconsistent with the expected numbers of mutations between twins then we could be pretty sure it’s not genetic.
or perhaps it’s only partially genetic, again twins and siblings would let us work this out.
Yes, that’s definitely true. If you know a little, or a lot, about genetics, then the theory is falsifiable.
I think it still works just fine as an example though. The goal was to explain the meaning and the importance of falsifiability. Spotiswood’s theory, as presented and as it was being used, wasn’t making any useful predictions. No one was looking at familial comparisons, and i implied that Spotiswood wasn’t making any effort to identify the gene, so the only observations that were coming in were “person lives”, or “person dies”. Within that context, Spotiswood’s theory can explain any observation, and makes no useful predictions.
If that’s not an example of an unfalsifiable theory, then it’s still an example that helps explain the key elements of unfalsifiability, and helps explain why they’re important.
If an audience member should then point out what you pointed out? Then that’s brilliant. We can agree with the audience member, and talk about how this new consideration shows that the theory can be falsifiable after all.
But then we also get to point out how this falsifiability is what makes a theory much more useful… and the example still works because (QED) that’s exactly the point we were trying to demonstrate.
Incidentally, i think that you’re proposing a test for susceptibility to the medicine. The relevant theory here is that any person who would be killed by a full dose, would be also be harmed but not killed, by a much smaller dose. That’s a perfectly testable, falsifiable theory, but i don’t think it would directly test the claim that the cause is genetic.
A better test for genetic causes, is to look at family relationships. If we believe the cause is genetic, then we predict that people who are more closely related to each other, are more likely to have the same reaction to the medicine. And we predict that identical twins would always have the exact same reaction to the medicine.
The original poster was looking for a very easy example that children could follow, without needing to understand any maths or probability theory, so I wanted to keep it simple. That’s why i didn’t mention the idea of improving the original scientist’s theory.
If the first scientist can come up with a way to test his theory, then it would probably make his theory more useful. It would also make it more falsifiable.
I think it would be great to start with a theory that sounds very scientific, but is unfalsifiable, and therefore useless. Then we modify the theory to include an element that is falisfiable, and the theory becomes much more useful.
For example, we have a new kind of medicine, and it is very good for some people, but when other people take the medicine it kills them. Naturally, we want to know who would be killed by the medicine, and who would be helped by it.
A scientist has a theory. He believes there is a gene that he calls the “Spottiswood gene”. Anyone who has the proper form of the Spottiswood gene will be safe, they can take the medicine freely. But some people have a broken version of the Spottiswood gene, and they die when then they take the medicine. Unfortunately the scientist has no way of detecting the Spottiswood gene, so he can’t tell you whether you have the gene or not.
Now this theory sounds very scientific and it’s got lots of scientific words in it, but it isn’t very useful. The scientist doesn’t know how to detect the gene, so he can’t tell you whether you are going to live or whether you are going to die. He can’t tell you whether it is safe to take the medicine. If you take the pill and you survive, then the scientist will say that you had the working version of the gene. If you take the pill and you die, the scientist will say that you have the broken version of the gene. But he cannot say what will happen to you until after it has already happened, so his theory is useless. He can explain anything, but he can’t make predictions in advance.
Now another scientist has a different theory. She thinks that the medicine is related to eye color. She thinks anyone with blue eyes will die if they take the medicine, and she thinks that anyone with brown eyes will be okay. She’s not sure why this happens, but she plans to do more research and find out. Even if she doesn’t do any more research, her theory is much more useful than than the first scientist’s theory. If she’s right, then blue-eyed people will know that they should avoid the medicine, and brown eyed people will know that they can take the medicine safely. She has made predictions. She predicts that no brown eyed person will die after taking the medicine, and she predicts that no blue eyed person will live.
Of course, the second scientist might be wrong. But the interesting thing is that if she’s wrong, then we can prove that she’s wrong. She predicted that no one with brown eyes will die after taking the medicine, so if lots of people with brown eyes die, then we will know that she’s wrong.
If her theory is wrong, then we should be able to prove that it’s wrong. And then if the results don’t prove that she’s wrong, we accept that she’s probably right. That’s called falsifiability.
But the first scientist doesn’t have falsifiability. We know that even If he’s wrong, we’ll never be able to prove it—and that means we’ll never know if he’s wrong or right. More importantly, even he is right, his theory still wouldn’t do anybody any good.
The first theory is falsifiable as long as you’re willing to let enough people die. Collect blood samples from everyone before they take the medecine. Sequence their full exome and put it on file.
once you have a few thousand dead and a few thousand survivors you should be able to narrow candidates down to a few dozen genes.
Make predictions about who will die out of the next few hundred who take the pill, bam.
Turns out it’s an eye color gene having some weird effect on a vital pathway that the drug is linked to.
Alternatively if it’s not genetic at all, if single members of pairs of twins taking the drug died at rates inconsistent with the expected numbers of mutations between twins then we could be pretty sure it’s not genetic.
or perhaps it’s only partially genetic, again twins and siblings would let us work this out.
Seems pretty falsifiable.
Yes, that’s definitely true. If you know a little, or a lot, about genetics, then the theory is falsifiable.
I think it still works just fine as an example though. The goal was to explain the meaning and the importance of falsifiability. Spotiswood’s theory, as presented and as it was being used, wasn’t making any useful predictions. No one was looking at familial comparisons, and i implied that Spotiswood wasn’t making any effort to identify the gene, so the only observations that were coming in were “person lives”, or “person dies”. Within that context, Spotiswood’s theory can explain any observation, and makes no useful predictions.
If that’s not an example of an unfalsifiable theory, then it’s still an example that helps explain the key elements of unfalsifiability, and helps explain why they’re important.
If an audience member should then point out what you pointed out? Then that’s brilliant. We can agree with the audience member, and talk about how this new consideration shows that the theory can be falsifiable after all.
But then we also get to point out how this falsifiability is what makes a theory much more useful… and the example still works because (QED) that’s exactly the point we were trying to demonstrate.
Couldn’t Spottiswood make a gene-detector by feeding the medicine in tiny tiny amount and seeing whether you just died a bit? Could be way useful.
Incidentally, i think that you’re proposing a test for susceptibility to the medicine. The relevant theory here is that any person who would be killed by a full dose, would be also be harmed but not killed, by a much smaller dose. That’s a perfectly testable, falsifiable theory, but i don’t think it would directly test the claim that the cause is genetic.
A better test for genetic causes, is to look at family relationships. If we believe the cause is genetic, then we predict that people who are more closely related to each other, are more likely to have the same reaction to the medicine. And we predict that identical twins would always have the exact same reaction to the medicine.
The original poster was looking for a very easy example that children could follow, without needing to understand any maths or probability theory, so I wanted to keep it simple. That’s why i didn’t mention the idea of improving the original scientist’s theory.
Absolutely.
If the first scientist can come up with a way to test his theory, then it would probably make his theory more useful. It would also make it more falsifiable.