Why Fallacies are False -- 004, Conjunctions and Conspiracy Theories

You’ve had a week now to think about that last statement. If you teach somebody about the Conjunction fallacy and why it’s wrong, at a later time they will STILL PICK THE WRONG STATEMENT AS MORE LIKELY.

If they’re looking at the exact same problem, that’s nuts. But it could be a matter of not realizing they’ve seen it before. We all forget things.

To show you how conspiracy theories are Linda problems, I have to emphasize some things.

First, it is irrelevant whether the “description of Linda” dataset is true or false. It’s just a bunch of information labeled Linda for the purposes of the explanation. You could collect sports statistics and that would still be your dataset.

The important thing is that both your X and your Y have nothing in common with that dataset. In the classic problem, the first statement is that Linda is a bank teller. Nothing in the description says she went to business school or college or any training sessions that qualify you to be a bank teller. If your conspiracy theory is a real conjunction fallacy, the simple statement will have nothing in common with your dataset. If it does, you’re not looking at a conjunction fallacy.

The same is true about your Y, which in the classic problem says Linda is a feminist. Again, there’s nothing in the dataset that says she belongs to NOW or any other woman-oriented organization, or that she participated in feminist protests. Again, if the “Y” in your conspiracy theory actually has a relationship to your dataset, it’s not a real conjunction fallacy.

At that point, it becomes important if your dataset has falsehoods in it. If you can prove that, you prove the whole thing is probably not true. Same if the connection between the dataset and the other statements have fallacies in them.

Once you pick your dataset, be careful with the claims you make about it. Prove the X claim. Then you can go on and prove the Y claim. And THEN you can make a probably true conjunctive claim involving X and Y. And this is exactly what science does, under Cartesian method: break a problem up into pieces; prove one piece true at a time; and then combine them.

Highly educated people face as much risk of creating and believing conspiracy theories as people who left school in their teens. Higher education does not force people to learn about fallacies. Even if STEM training teaches Cartesian method, they don’t necessarily lecture on the connections to logic or why the Method helps prevent creation of fallacies.

Next time I’ll give an example of a conjunction that never heard of Cartesian method.