“Conjunction fallacy is not actually a fallacy” seems like overselling the result, but Dr. Jamchie has a point. Imagine I’m thinking of a person named Bob. You have two hypotheses:
1) “Bob is a mathematician” with probability 0.5
2) “Bob is a mathematician and a plumber” with probability 0.1
Then you receive evidence that Bob fixed my water heater, updating the probabilities to 0.4 and 0.2. The first one is still higher, as it should be, but the second one got a bigger boost from the evidence (aka “likelihood”).
“Conjunction fallacy is not actually a fallacy” seems like overselling the result, but Dr. Jamchie has a point. Imagine I’m thinking of a person named Bob. You have two hypotheses:
1) “Bob is a mathematician” with probability 0.5
2) “Bob is a mathematician and a plumber” with probability 0.1
Then you receive evidence that Bob fixed my water heater, updating the probabilities to 0.4 and 0.2. The first one is still higher, as it should be, but the second one got a bigger boost from the evidence (aka “likelihood”).