r/science • u/mvea Professor | Medicine • 20d ago

Neuroscience 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.

https://www.psypost.org/twin-study-suggests-rationality-and-intelligence-share-the-same-genetic-roots/
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u/girlyfoodadventures 19d ago

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.

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u/Merry-Lane 19d ago edited 19d ago

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.

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u/thesmellofrain- 19d ago

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.

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u/Merry-Lane 19d ago

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.

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u/thesmellofrain- 19d ago

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.