Can you outsmart this logical fallacy? - Alex Gendler

Explore the psychology of the cognitive bias known as the conjunction fallacy, where we assume specific conditions are more probable than general ones.

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Meet Lucy. She was a math major in college, and aced all her courses in probability and statistics. Which do you think is more likely: that Lucy is a portrait artist, or that Lucy is a portrait artist who also plays poker? How do we know which statement is more likely to be true? Alex Gendler explores our tendency to look for shortcuts and the phenomenon known as the conjunction fallacy.

Lesson by Alex Gendler, directed by Artrake Studio.

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[SehnsuchtYT]

Reminds me of the joke advice that you should take a zebra on a train with you, because statistically train crashes when there is a zebra on board are much more unlikely.

[JaswiL-_]

Ted-Ed : Can you-
Me : no, but i’ll watch it anyway so i can

[atlas]

My dad told me a joke that reminds me of this “All schools should adopt llamas, because statistically, a school shooting is less likely to happen if a llama is present.”

I think what happens in most people heads is that when you say "Is she more probable to be a painter or to be a painter plus a poker player?" they really hear "Is she more probable to be a painter who does not play poker or a painter who does?" I'm not quite sure it really is a problem about probabilistic intuitions (though as less people play pocker it still may be), rather than a problem with framing and rhetoric in language, that is, a problem with miscommunication. What if you rather ask people if it's more probable that she's a painter who may or may not play poker, or that she's a painter who plays poker? I would say more people would answer the question correctly, when the question is correctly framed.

[zur]

I constantly overestimate my ability to outsmart anything.

[sebastianelytron]

Ted-Ed gave up on me trying to "solve" anything so they thought I might be able to "outsmart" something... sorry Ted-Ed, I can't do that either😅

[fugueoffiber]

As an art major, I had peers who made beautiful art and majored in math. Knitting, crocheting, and weaving can use a ton of math (go ahead and make a swatch, and use it to construct a full garment by yourself). One of my favorite studies a peer did was by shibori dyeing fabric in the form of fractals.

[fedeganimation]

I think something important here is how human communication works as well. When someone says that one person does one thing and the other one does the same thing and something else, is implying that the first one doesn't do the second thing. Is how we as humans communicate most of the time, it would be weird te clarify every time that the first person COULD also do the second thing. Either way, the example you bring here is interesting regardless what I just said.

[kevinnelson]

Lesson learned, always include as many details as possible when lying.

[CrosswaIk]

This is the only ted-ed I've ever instantly understood and solved!

[ExdeathZ]

I feel like this is less of a fallacy and more of poor understanding of linguistics. When presented with the choices, of the person being an artist vs an artist and poker player, it is implied by the phrasing of the second option that the first excludes the second group. Given that we are working with the knowledge that the person is definitely an artist, the question morphs into "is it more likely that the person is or is not a poker player given their interest in these related subjects?"

[honeybadger]

Flashbacks to kahoot where i felt rushed to get more points and pick the complicated answer.

[abrohamproductions]

I didn't know this was a fallacy, I just thought it was common sense to choose the one with less specifics added onto it.

[iancuvlad]

2:20 Misinterpretation might occur, when the question is asked, one might think that it's more likely for Lucy to be an artist which plays poker rather than a one who does not play poker.

[rayrowley]

The problem for me is that I interpret the question to be, "Is it more likely Lucy is a portrait artist who does NOT play poker, or that Lucy is a portrait artist who DOES play poker?" When asked a 'this or that' question, the answers are almost always mutually exclusive and rarely if ever self contained so we skip to looking at the difference and seeing which of the different parts is more likely. I know it is not technically worded that way, but it could be interpreted that way if one sees 'does not play poker' as implied.
Ask people if it is more likely that Lucy is a portrait artist who may or may not play poker or that she is a portrait artist who does play poker and I suspect many more people will get it correct.
TLDR: It's the wording not the math.

[nikolausbeer]

If you're interested in that kind of stuff, I recommend "Thinking fast and slow" by Daniel Kahneman

[generaltomfoolery]

This is the first time in my life that I was able to realise the right answer in a Ted video on my own, I'm gonna cherish this for I know it's statistically unlikely that it will ever happen again.

[stiltzkinvanserine]

To outsmart this logical fallacy, one must shave with Occam's Razor.

[JadedView]

This is similar to when teachers tell you you picked the right answer on a test, but another answer was more right.

[ourtube]

What if the statement were altered?

1. Lucy is a portrait artist who doesn’t play poker
2. Lucy is a portrait artist that plays poker

The condition is then exclusionary so it is no longer subject to a conjunction fallacy.

All you need is 50% of people like Lucy to be poker players and then the tables are turned.

A similar case is:
Which is more likely?
John is born in England
or
John is born in England and has 10 fingers

The more general guess is correct but if we add the exclusionary condition then it’s extremely obvious that it would be more likely for John to have 10 fingers as opposed to some other number.

I don’t think this “conjunction fallacy” is given justice here. The video really just says that people will mentally substitute a nested probability question for a True/False binary question unless the question is phrased in a way that is less ambiguous.