This is why I asked for specific examples. I fear that even if you were able to remember specifics, your story would break down just like your hypothetical one has.
I’m sure a real example would’ve been more convincing, but it was 25 years ago, I can’t remember one. But my point still stands: Common sense isn’t common. We all think too differently for that to be so.
My therapist once told me that the only difference in those of higher intelligence is that they are better at rationalizing and obfuscating their points.
In other words, the smarter you are, the easier it is for you to come up with a believable lie–even one you yourself believe.
Hell, one of the proposed reasons for the intelligence explosion in human primates is that there was a feedback loop where each of us had to get smarter to outsmart the previously smartest person in order to reproduce.
As God as my witness, I thought turkeys could fly! 
Coincidentally, I have the same IQ as the person mentioned in the OP. I can say myself that I’ve believed some unusual things over time, though a lot of that had to do with how I was raised and I eventually realized I was wrong. That said, I still have some beliefs that aren’t mainstream, not conspiracy theory types of beliefs, more of the philosophical kind.
That said, I do recall reading about a study once that actually indicated that intelligent people are often more likely than those of average intelligence to fall for conspiracy theories and scams and such. As far as conspiracy theories go, part of the justification is that a large part of what makes people intelligent is their ability to recognize patterns, and this can lead to identifying patterns that aren’t there, and their high intelligence can also lead to distrusting the opinions of others who are less intelligent. And it’s similar with scams, trusting their own ability to judge an opportunity too much, possibly not realizing that parts of it are out of their competence, and thus falling for the scam.
But even putting that study aside, there’s intelligent people all over the place. You can find them all over the political spectrum, though there are some areas where they are more or less common. Similarly, you can find them of all sorts of religious varieties. And you’ll certainly find them believing plenty of nonsense too. If someone is really intelligent and knows a lot one or even several topics, they may be thoroughly ignorant on another and just fall into believing something pretty silly.
And I can also say, speaking for myself, that sometimes I formulate a belief and can get stuck going in my head creating all kinds of convoluted justifications, even if the original belief is more or less on a whim. I’ve put in a lot of time learning how to identify what beliefs I have that are legitimately backed up by reason, which ones are based on opinion or taste (and should be, like music, food preferences, etc), and which ones are basically derived from intellectual masturbation, and I’ve largely learned how to unwind them. Sometimes I still need someone to call me out on them though.
Despite how badly your hypothetical example failed to prove your point, I think this point is still valid. We see a lot egregious folderol aggressively defended by the clueless by calling it “common sense”, so calling anything “common sense” feels like begging the question.
ETA: The other phrase I’ve learned to treat as a red flag for idiocy is “It stands to reason…” “It stands to reason that there’s no such thing as global warming.” “Umm… it’s been very carefully reasoned out that AGW is occurring.”
STOP TALKING ABOUT ME!!!
I know you all hate me. sniffle
Why on earth would you believe your friend’s reported IQ, since he’s wrong about everything else?
This was my experience also. When I took the proctored Mensa test, at 17, I scored 142. Since then, I’ve taken at least one other different IQ test in which I scored slightly lower but, as JerrySTL says, that score was considered higher than the 148 and both above the 98th percentile.
Here we go.
Common doesn’t mean universal. Common sense is only common because most people think that way. Consider if you asked a thousand people what they would have done in your situation.
A) write down the message and leave it somewhere roommate will see it
B) deliver the message verbally next time you see roommate
C) ignore the message entirely - do not tell rommate
The most common answer would be A. But surely, you and a few others would have chosen B and some asshole would even have said C.
I don’t even think it means that. “Common sense”, to my hear, means knowledge basic enough for a commoner to have. Has nothing to do with prevalence, and all to do with simplicity.
That’s my understanding as well. It means something that someone without any sort of specialized knowledge could figure out correctly.
From wiki:
“Common sense is a basic ability to perceive, understand, and judge things, which is shared by (“common to”) nearly all people, and can be reasonably expected of nearly all people without any need for debate.”
It’s not common because commoners possess it. It’s common because it’s not rare.
But the reason it’s not rare is because it’s a basic ability.
There is plenty of knowledge that is common that I wouldn’t call “common sense”. For instance, the vast majority of the planet knows that Obama is the first black president of the U.S. But this is knowledge that you have to acquire from an outside source; it isn’t something you can figure out through basic brain work.
Ah yes. Just because you can polymorph yourself into a Hippopotamus to charge through the burning oil blocking the castle gate doesn’t mean you should
Player: “But…but…hippos are fireproof! They’re wet and live under water!”
DM: “Are you roleplaying your wisdom score right now? Because if not, maybe we should talk outside the room for a few seconds”
I’ve always been pleased this distinction was made. Having a high intelligence score is useless if you keep lording it over the half orcs who can only come up with direct, inelegant answers to, “How do we best shut this guy up?” Int 17 & Wis 5 just doesn’t work out to a very productive life in a world that favors Int 5 & Str 17.
To the OP: Seems like there should be an algorithm to modify Cha if Wis & Int are too far apart.
Like you and JerrySTL I took a proctored test and got a 154 and then years later I took another one and got a 147. I then decided that the second test was wrong because I am obviously smarter than the person who wrote the test so I just tell everyone it’s 154.
You could just take the average, which if I’m not mistaken is 7.
But Wisdom is the requisite ability for religious belief, for cleric characters. In real life, wisdom and religious belief don’t necessarily positively correlate.