Hacker News new | past | comments | ask | show | jobs | submit login

'There is also a blatant error in the OP article: Answer No. 2 (Linda is a bank teller and is active in the feminist movement.) is by no means "logically impossible".'

They meant that it's logically impossible for the probability of A AND B to be higher than the probability of A, since A AND B is a subset of A. She could be feminist, but the probability of being feminist is lower than the 100% probability that she's either a feminist or not.




I am well aware of the point they were trying to make. Or, more precisely, the point Kahneman et al. were trying to make. What I am concerned about is that they, that is, the editors / writers of Vanity Fair, do not understand their mistake. This is somewhat likely given the error they made described by the grandparent comment.

Overall, I find it rather ironic to find such gross errors in an article that sets out to educate the reader about "human error".


I'm going to copy/paste the relevant section:

Then they went around asking people the same question:

Which alternative is more probable?

(1) Linda is a bank teller.

(2) Linda is a bank teller and is active in the feminist movement.

The vast majority—roughly 85 percent—of the people they asked opted for No. 2, even though No. 2 is logically impossible. (If No. 2 is true, so is No. 1.)

They say: "If No. 2 is true, so is No. 1.", but they omit that the opposite does not hold. Perhaps they thought it was obvious enough.

I think they get it and just left that second part out. They may have worded it poorly (better would be "it is logically impossible that #2 could be the correct answer"), but it was very clear to me when reading the article that the editors meant exactly what you describe.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: