Not all Extraordinary Claims are Equal

In #articles

It's the beginning of the school year and time to get back into writing and exploring interesting scientific questions, or at least exploring scientific thinking. We start with this article which maintains that extraordinary claims do not require extraordinary evidence. They make the analogy with a story about a vet claiming that a chicken gave birth to a chick internally, without laying the egg. The author states that he believes this claim, despite the meager evidence, because "this is the sort of evidence that I’d expect if the claim is true and not at all what I’d expect if the claim is false."

As a skeptic, I thought "well, that's unusual" but am also inclined to believe it - although not particularly strongly. Why? And does this undermine my skepticism for other extraordinary claims? Here are five reasons for why I believe the claim (but not strongly) and why it is different than many other extraordinary claims:

  1. we have the word of a trained scientist, who'd be in the position to tell the difference between a hoax and something legitimate
  2. we understand that the biological mechanisms of birth are stochastic, and this sort of thing is totally within the possibility of the biology
  3. it led to the death of the hen, which is the most likely outcome in such a rare case
  4. although the prior probability of such a thing happening is small, we have many chickens in the world. It's like winning the lottery twice - it happens frequently because there are so many people playing lotteries.
  5. I'm still a little dubious, because I can't find any other corroboration, and the story is sensational enough to warrant making it up, so I wouldn't stake my life on the story.

Maybe a probability of about 80 percent?

Now, ask yourself, other than point (5), do we have for any ancient miracles, or for that matter any other supernatural claims, an analogous match to any of the points 1-4?