You ever see a dog that’s got its leash tangled the long way round a table leg, and it just cannot grasp what the problem is or how to fix it? It can see all the components laid out in front of it, but it’s never going to make the connection.
Obviously some dog breeds are smarter than others, ditto individual dogs - but you get the concept.
Is there an equivalent for humans? What ridiculously simple concept would have aliens facetentacling as they see us stumble around and utterly fail to reason about it?
Probability. If something has a 50% chance of occuring, that does not mean it will happen every second time, and our brain has a very hard time rationalizing that. For example, we assume its near impossible to flip heads on a coin three times in a row when really, the probability is 12.5% - not that low. Another example would be something with a 95% chance of success - we naturally round up and assume thats basically garenteed success, but theres still a very decent chance of failure, esspecially on repeat attempts. Our brains are just not wired to handle randomness well, which is part of why gambling is so addicting and why games like X-Com have to rig the odds in the players favour to avoid pissing them off.
And that past random events have no influence on future ones.
If a coin landed on one side ten times in a row, it’s still a 50% chance on the next throw. Something a lot of people have trouble with.
This is my answer as well.
We have developed intuition around things like naive physics - you can catch a thrown frisbee without doing calculus in your head - but it’s really, really hard to think through statistical questions in an intuitive way.
It’s one reason I’m extremely skeptical about the utility of informed consent in medicine. A physician can tell a patient’s family that if they don’t do the procedure then the patient will definitely die, but if they do it there’s a 20% chance of complication A and a 5% chance of complication B. The right thing to do is plan on the complications happening and having a realistic idea of what that will entail. But people, especially under stress, really aren’t able to deal with that kind of thing as easily as they can deal with catching a ball thrown to them.