Wikipedia defines common sense as “knowledge, judgement, and taste which is more or less universal and which is held more or less without reflection or argument”
Try to avoid using this topic to express niche or unpopular opinions (they’re a dime a dozen) but instead consider provable intuitive facts.
Pretty much anything related to statistics and probability. People have gut feelings because our minds are really good at finding patterns, but we’re also really good at making up patterns that don’t exist.
The one people probably have most experience with is the gambler’s fallacy. After losing more than expected, people think they’ll now be more likely to win.
I also like the Monty Hall problem and the birthday problem.
The gambler’s fallacy is pretty easy to get, as is the Monty Hall problem if you restate the question as having 100 doors instead of 3. But for the life of me I don’t think I’ll ever have an intuitive understanding of the birthday problem. That one just boggles my mind constantly.
Really? The birthday problem is a super simple multiplication, you can do it on paper. The only thing you really need to understand is the inversion of probability (
P(A) = 1 - P(not A)).The Monty hall problem… I’ve understood it at times, but every time I come back to it I have to figure it out again, usually with help. That shit is unintuitive.
My favourite explanation of the Monty hall problem is that you probably picked the wrong door as your first choice (because there’s 2/3 chance of it being wrong). Therefore once the third door is removed and you’re given the option to switch you should, because assuming you did pick the wrong door first then the other door has to be the right one
Thanks for the help, it was easier this time 😅
Adding my own explanation, because I think it clicks better for me (especially when I write it down):
- Pick a door. You have a 66% chance of picking a wrong door, and a 33% of picking the right door.
- Monty excludes a door with 100% certainty
- IF you picked a wrong door, then there’s a 100% chance the remaining door is correct (so the contingent probability is
p(switch|picked wrong) = 100%), so the total chance of the remaining door being correct isp(switch|picked wrong)* p(picked wrong) = 66%. - IF you picked the right door, then Monty’s reveal gives you no new information, because both the other doors were wrong, so
p(switch|picked right) = 50%, which means thatp(switch|picked right) * p(picked right) = 50% * 33% = 17%. p(don't switch|picked wrong) * p(picked wrong) = 50% * 66% = 33%(because of the remaining doors including the one you picked, you have no more information)p(don't switch|picked right) * p(picked right) = 50% * 33% = 17%(because both of the unpicked doors are wrong, Monty didn’t give you more information)
So there’s a strong benefit of switching (66% to 33%) if you picked wrong, and even odds of switching if you picked right (17% in both cases).
Please feel free to correct me if I’m wrong here.
One of my favourite pages on wikipedia:
The immune system is strong and defends your body against germs.
The immune system works 100% of 50% of the time. Immunology is the best way to convince someone that it’s a miracle that they’re still alive. Anyways, get vaccinated. Don’t rely on your immune system to figure things out
Don’t rely on your immune system to figure things out
… in time to keep you alive. I mean, given enough time, the body will figure things out. Vaccines are cheat-sheets to cut that time so it’s accomplished before the host dies.
The immune system is strong and defends your body against germs.
Which is why you should get vaccinated.
Vaccination primes your immune system so it can mount a coordinated response the first time it actually encounters the pathogen.
Yup, vaccination isn’t reinforcements, it’s training. It’s having the other team’s playbook before they even step foot on the field.
Umm, it’s your immune system that detects the vaccine and responds to it by developing antibodies specific to the vaccine (and by extension to the actual disease). Just as it would when challenged in real life by the pathogen.
Vaccination basically gives your immune system a several day head start on producing antibodies.
Not entirely true. Vaccines induce the adaptive immune system, which is slow but precise. Getting sick for real induces the innate immune system, which is god awful and you should not be relying on it. S. pneumoniae causes pneumonia because the innate immune system goes overdrive and kills you before it kills the bacteria. COVID-19 induces cell-innate inflammasome activation and leads to a cytokine storm, which then leads to even more damage to the lungs as the immune cells come in. Both diseases have effective vaccines that do not do anything close to this.
Deadly diseases tend to be deadly not because of the microbe itself, but because the innate immune system overreacts and kills you in the process of fighting off the disease.
Getting vaccinated diminishes the role that the innate immune system plays when you get sick, since the B cells responsible for producing antibodies for the disease are already mature. Having available antibodies also allows the immune system to rely on the complement system, which allows it to detect and kill invading microbes way earlier than otherwise.
This is actually good common sense. It works much more than 50% of the time. You’re responding to the very specific instance of anti-vaxxers, whose claims of relying on the immune system instead of vaccines are not considered common sense by most people.
No, I’m responding to regular people. Your immune system is way less effective than you think, hence the wrong common sense part.
Less tax is better.
No saying that taxation as it currently exists it optimal, but any decent assessment of how to improve things requires a lot of nuance that is nearly never considered by most people.
A lot of outdoor survival “common sense” can get you killed:
Moss doesn’t exclusively grow on the north side of trees. Local conditions are too chaotic and affect what side is most conducive to moss. Don’t use moss for navigation.
Don’t drink alcohol to warm yourself up. It feels warm but actually does the opposite: alcohol opens up your capillaries and allows more heat to escape through your skin, which means you lose body heat a lot faster.
Don’t eat snow to rehydrate yourself. It will only make you freeze to death faster. Melt the snow outside of your body first.
Don’t assume a berry is safe to eat just because you see birds eating them. You’re not a bird. Your digestive system is very different from a bird’s digestive system.
If you’ve been starving for a long time, don’t gorge yourself at the first opportunity when you get back to civilization. You can get refeeding syndrome which can kill you. It’s best to go to the hospital where you can be monitored and have nutrients slowly reintroduced in a way that won’t upset the precarious balance your body has found itself in.
Moss doesn’t exclusively grow on the north side of trees.
My brain was like “why do people so desperately need to find moss that it not being on the north side would mean death?” Before remembering many people don’t know which way they are facing (or left and right) usually. (Also, I’m sure I’d do worse in an unfamiliar area)
‘Building more lanes will reduce traffic’ is a classic.
They enlarged rt 3 near rt 95 in MA many years ago. It was getting backed up due to all of the people moving further out from Boston. I said “It will be full again in a few years.” Yup. It was moving well for a few years so everyone piled into that area because the commute was better and within a few years it was a traffic jam again.
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that putting the thermostat up higher will heat the house up quicker (edit: I have in mind a bog standard UK home thermostat)
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that sugary sweets make kids act “hyper”
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that the moon’s apparent size is due to how close it is to earth (same for seasons and the sun)
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that your base metabolic rate slows as you age and is primarily responsible for you putting weight on in middle age
In the case of inverter air conditioning it might make a small difference at it won’t throttle down as it approaches the intended, not commanded, target.
that putting the thermostat up higher will heat the house up quicker
If you have a 2 stage furnace, this may actually be a thing.
that your base metabolic rate slows as you age and is primarily responsible for you putting weight on in middle age
Is this not true?
No. At least, it’s not the general cause of ‘middle age spread’.
The base metabolic rate refers to how your individual cells respire when at rest. And a brain cell in 20 year old respires much the same way as a brain cell in a 45 year old. Same for all other organs. There is a gradual decline but it’s on the order a single percents.
Organs and tissue at rest respire at different rates, so some of the change people notice is due to change in body composition. Muscle at rest burns twice the calories as fat however this is still only a minor contribution.
Base metabolic rate doesn’t vary much at all. The vast difference in daily calories consumed as one ages is general activity level.
Overall metabolic rate = base rate (varies a little on body composition) + calories burned in general activity (varies a lot)
People typically are less active between 20 and 40. This is not just sport but also lifestyle. People become more efficient in their habits as they age. They drive instead of biking or walking. They sit in the sun on holiday with nice food and wine rather than dancing all night. Etc
Lifestyle choice is the primary cause of excess calorie intake and ‘middle age spread’. Not “my metabolism that I can’t do anything about”.
that putting the thermostat up higher will heat the house up quicker
Same with electric range/ovens.
Huh, these are all common sense statements I would have assumed true. Four our of four, good work!
- that sugary sweets make kids act “hyper”
Do you happen to have a source for that? Coz I have witnessed kids act like a horde of wild monkeys on crack right after eating dessert on multiple occasions.
I listed it because it’s one of the things I would sworn by too having seen it first hand. However when you conduct a double blind experiment, kids still get excited at parties / treats / days out / when their friends are over when there’s no sugar in the treats.
https://www.medicalnewstoday.com/articles/medical-myths-does-sugar-make-children-hyperactive
In otherwords as parents we massively underestimate how excited or crazy kids can get just because they’re excited and not because of something in their bloodstream…
That may be the case. I will need to conduct my own research^^
Make sure it’s a blind test ;)
The claim and evidence here are not logically consistent.
It’s like saying “cyanide won’t make you dead” because, look “people still get dead from falling and crocodiles, even if there’s no cyanide around”.
no, it’s not. it’s a meta analysis of multiple double blind studies. multiple
“For the children described as sugar-sensitive, there were no significant differences among the three diets in any of 39 behavioral and cognitive variables. For the preschool children, only 4 of the 31 measures differed significantly among the three diets, and there was no consistent pattern in the differences that were observed.”
if you did the same with cyanide you would be able to conclude that “taking cyanide and being dead is positively correlated” even if there were other causes of death. in this wide summary of multiple double blind experiements, there is no correlation between sugar intake and child behaviour. that’s not to say kids don’t act up and get hyper, but it’s other causes, most signficantly parents just underestimate how hard kids find it to regulate themselves when having treats of any sort (non-sugar included) or being in a party atmosphere with friends.
that the moon’s apparent size is due to how close it is to earth (same for seasons and the sun)
Explain?
Also, what’s the size/proximity of seasons?
The visual difference of the minimoon and supermoon is not that great, see here but hold your phone at arms length. This is the maximum difference (taken 6 months apart) that the moon ever is relative to itself. In practice, from one night to the next or one month to the next the difference is barely noticeable.
When people say “the moon was huge tonight” what they are generally seeing is the moon illusion
The reference to seasons is badly worded, but what I was referring to is that the earths seasons have nothing to do with how close to the sun it is
Ah, I didn’t realize the moon could look bigger/smaller at different times. I thought you were saying that the moon is actually the same size as the sun or something like that.
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To tilt your head back if you have a blood nose.
This is no longer recommended advice, because you end up drinking the blood which causes vomiting.
- Probably initially said by someone concerned about their carpet.
Way to stop them is put ice over the back of neck, plug nose with tissue and clear clots each 2 mins.
Any reason not to just let it run? If not on blood thinners.
You can let it run.
I find it clots better by using tissues to plug the flow.
Cold Air will make you sick.
There are plenty of studies debunking it, and yet I still hear about it all the time.
I’ve been hearing it for years, always argued against it.
Common sense itself.
Some people put way too much stock in “common sense” as some blanket assumption and insult to lob at anything and everything they don’t like.
They internally define what they believe to be “common” and everything that deviates is outside of that. They use it to fuel their own sense of self satisfaction and smugness, while additionally fueling negativity and hatred for others.
It fuels their toxicity and comes to define their view of everything, which is typically grossly oversimplified for their own needs.
Precisely.
Is common sense just an earlier, naive label for confirmation bias?
A key aspect is that it doesn’t even require confirmation.
“Bigger is better”
The most vulnerable will be hit the hardest.
- Countries are rich because they have free markets.
- Tariffs are a good thing and competition is for losers.
- No one deserves a handout, as money should be earned.
- Large companies deserve a giant economic stimilus, because if we don’t, our economy will crash.
- Being spied upon by your government or foreign governments whom I worship is okay, because I’ve got nothing to hide.
- Outsiders that sells goods that can be used to spy obviously and should be barred from all markets forever because they’ll definitely spy on you and spying is wrong.
- If you feel threatened by another country, a pre-emptive strike should be allowed.
- You don’t mess with the sovereignty of a nation. It’s sacred and should be left intact.
- Police should always be allowed to use overwhelming force and their actions should be lauded
- You should have the right to protect yourself using firearms against tyranny as governments in general are never to be trusted.
Is the goal to point out contradictions in the pairs you gave?
the sky is blue
an unbiased perspectiveMore abstract concepts that generally trouble the intuition of many:
the irrelevance of laminar to turbulent flow
time and gravity are related
magnetism is not magic
entropy precludes perpetual motionThe sky isn’t blue in many cultures. It’s been shown that words for blue only occur in a language after that culture has discovered a blue dye. And that limitation in available words also constrains how you see and think about the world.
This is covered in Guy Deutscher’s book The Unfolding of Language, which is an excellent read.
I was going with Rayleigh scattering, but that works too
The sky is actually the entire colour spectrum with a bias toward the short wavelength end of the spectrum, which is why it appears pale blue-ish white.
If “common sense is not very common”, why is it called common sense?
Slightly off topic, sorry.
A bird in the hand is worth two in the bush?
That means you ahould take the immesiate payoff or be happy with what you have instead of spensing a bunch of time trying to get more.
it also means don’t risk everything you have for a somewhat opaque promise of something better
Hehe ok I’ll wear those down votes. I didn’t understand the reference as I heard it first on The Two Ronnies as ‘a bird in the hand is worth two in the shepherd’s bush’ which I think think might be a carry-on reference.
I didn’t see why l would want a bird in my hand in the first place.
PS - what happened to your D key?
I switched keyboards on android, new one doesn’t have autocorrect or swipe, but it doesn’t connect to the internet. I don’t always proofread posts.
