Twin study suggests rationality and intelligence share the same genetic roots - the study suggests that being irrational, or making illogical choices, might simply be another way of measuring lower intelligence.

[u/mvea]

https://www.psypost.org/twin-study-suggests-rationality-and-intelligence-share-the-same-genetic-roots/

[u/peteypete78]

Dumb people make dumb decisions? Who would have thunk it.

[u/BrainKatana → u/peteypete78]

Incredibly smart people also make dumb decisions so something seems off about this study.

[u/Sinai → u/BrainKatana]

That's the great thing about quantitative testing, because you can show exactly how much more often dumb people make of wrong decisions in different situations, and then you have learned something about how much more or less intelligence matters in different situations.

[u/girlyfoodadventures → u/Sinai]

Intelligence/"good decision making" in a lab setting is very different from doing the same "in real life".

Intelligence is not the same thing as impulse control.

I was a smart kid and young adult, and I can assure you that knowing what the good decision is does NOT mean you'll make it. As I've gotten older (and after a pretty bad injury), I'm a little more risk averse, but as a young person I absolutely did risky things that I knew were dangerous because it seemed fun.

[u/Merry-Lane → u/girlyfoodadventures]

Of course, but they are still really tightly coupled.

These qualities being tightly coupled doesn’t mean that you can’t have unbalanced profiles, just that they are pretty much always similar.

If 8 out of 10 smart people are also highly rational, and 8 out of 10 dumb are irrational, they are tightly coupled. If it was 5/5, it wouldn’t be coupled.

Anyway, nothing indicates they aren’t tightly coupled, on the contrary.

[u/thesmellofrain- → u/Merry-Lane]

Couldn't you attribute that to another psychological trait that would act as a confounding variable? For instance, "fearfulness" could be a different lever that exists in varying degrees across people regardless of their intelligence. Or say someone just doesn't care about money the way others might. They could make completely different life decisions that appear irrational.

Chris Langan comes to mind.

[u/Merry-Lane → u/thesmellofrain-]

I could attribute it to another variable, if I didn’t have one study that would say "intelligence and rationality are tightly coupled" in front of me, and none saying "rationality is coupled to another random variable".

Anyway what’s important is that there are some people that claim "IQ tests don’t test correctly intelligence because they don’t test X or Y". They can’t use rationality now.

[u/thesmellofrain- → u/Merry-Lane]

I'm not saying that it's incorrect. I guess I'm just slower to accept a world view just because of a study. I couldn't tell you how many times a conclusion from a study is reversed in the years after.

[u/demonicneon → u/Sinai]

Who decides what is irrational though?

[u/nickeypants → u/[deleted]]

Amazing to see how predictably human my brain is. I fell into the exact trap explained below the first puzzle despite taking a good 20 minutes to make up my mind, and got the social test almost immediately. Everyone should give this a try.

[u/ThrowbackPie → u/nickeypants]

What social test?

Edit: oh I just had to read more of the Wikipedia article.

[u/sybilsibyl → u/ThrowbackPie]

The third external link on the wiki page has a test too

[u/lafayette0508 → u/nickeypants]

wow, that is WILD. Same here. I'm so surprised that the same logical question had such a marked difference in how easy/hard it was to understand in the two instantiations.

[u/Sinai → u/lafayette0508]

As it says in the wikipedia article, one stance is that this is expected because of experience effects. It's harder to get a question right when you've never experienced it before, but almost everybody is familiar with alcohol age laws.

[u/RudeHero → u/[deleted]]

10% of test subjects get it right and that test was replicated.

Ha! For questions like that (and the "two items total $1.10" one in the article) I suspect a lot of it has to do with motivation. I.e., that 10% goes up if you promise to give them a hundred bucks if they get it right. I just wonder by how much

OP's article does suggest motivation as a target for follow up studies

[u/kiase → u/[deleted]]

I’d be interested in a two-parter that when participants are shown the answer of the 8 and red card, if they for example reveal the 8 card to be blue and the red card to be 5 if that proves the hypothesis that if a card shows an even number on one face, then it’s opposite face is blue. Basically studying if people correctly identify that correlation ≠ causation.

[u/lafayette0508 → u/kiase]

I agree - I would almost certainly get this question wrong due to time pressure and being put on the spot. But if you allowed me to follow through and turn over those cards, I'd realize that I was wrong, that I did not actually get the information I needed to make a logical conclusion, I'd figure out why I was wrong, and I'd readjust. I think that mirrors pretty well how I perform in the real world - I'm a moderately successful academic, but not the type that would do well on Jeopardy.

[u/zizp → u/[deleted]]

I don't like it. The result is heavily influenced by our ambiguous treatment of if vs iff in natural language. Unless the distinction is either clearly stated before the test or the participant is trained in basic logic, this only measures how people (mis)interpret the question based on everyday cultural background.

[u/narmerguy → u/zizp]

This is a really good observation. I was having difficulty figuring out how to approach this question until I realized that their use of if did not imply iff and then it became tractable. With time pressure I probably may not have caught the subtle language difference.

However, I would say anecdotally that the distinction between if and iff is something that I see people struggle with in day to day reasoning as well, not just because of language. It is connected to the difficulty with correlation not = causation.

[u/truealty → u/[deleted]]

This is just an application of conditional logic. I fail to see how it’s significantly different from an IQ test.

[u/truealty → u/[deleted]]

Sure. But if the study concluded “people who are good at IQ tests are also good at a subset of their material” it would seem vacuous, because it is. They’re exploiting the ambiguity of the word “rationality”.

[u/truealty → u/[deleted]]

Isn’t that already well-established? I think studies of, for example, the SAT or LSAT, show similar things. Being good at one section predicts your overall score pretty strongly. Personally I find it about as surprising as “your dribbling predicts your overall skill in basketball.”

Regardless, my issue isn’t with that conclusion, but more with the loaded terminology. “Rationality” colloquially means a lot more than “applied reasoning”, and in real life is often caused by psychological incentive against truth-seeking.

[u/demonicneon → u/[deleted]]

Doesn’t seem to test for the whole breadth of intelligence then does it though ? Also doesn’t represent real life whatsoever, where there are more situations that don’t have one correct answer, doesn’t account for social intelligences, or spacial, or musical, or…

[u/BonJovicus → u/Sinai]

That's the great thing about quantitative testing

Yes but that tells us very little about how this plays out for the individuals in their everyday lives. The study can say "on average X type of people exhibit Y% more behavior," but it is very clear that people in the thread or lay people in general will interpret this as "dumb people make dumb decisions and smart people make smart decisions", ergo if I think someone is dumb, all of their decisions are irrational whereas if I believe I am smart all my decisions are rational.

A better example might be clinical drug trials. For them to even make it to market they have to overall be both safe and effective on a population level, and yet there will always be patients for whom this is not true because of each individual's unique genetic AND environmental factors. I'm never surprised when medication that was worked well for one patient doesn't work well for the next one to walk in the clinic.

[u/Sinai → u/BonJovicus]

The failure of a percentage of laymen to interpret conclusions says nothing about the validity of the testing or its usefulness.

I drop a pass from an NFL quarterback, it doesn't mean he's a bad quarterback or that passer ratings are meaningless.