Common Sense? There May Not Be Anything Common About It

To those who see this title and say, “Well isn’t that just common sense?”, read on.

Holly Large - Editorial Assistant

Holly Large

Holly Large - Editorial Assistant

Holly Large

Jr Copy Editor & Staff Writer

Holly is a graduate medical biochemist with an enthusiasm for making science interesting, fun and accessible.

Jr Copy Editor & Staff Writer

Edited by Maddy Chapman

Maddy is a Editor and Writer at IFLScience, with a degree in biochemistry from the University of York.

two wooden puppets with confused faces, lines and arrows linking their heads

Common sense may be more individual than collective.

Image credit: Alex_Po/

“Ugh, nobody has any common sense these days!” We’ve probably all said it at one time or another, even though common sense is supposed to be this universal ability to know and understand something. A new study, however, suggests that there’s nothing universal about it at all – our sense of common sense may actually be less collective and more about personal perspective.

When a person calls something “common sense”, it generally means they think it should be viewed and understood in the same way by everyone. Researchers Mark Whiting and Duncan Watts from the University of Pennsylvania sought to determine what people believe to be common sense and to what degree this is, well, common.


The duo asked 2,046 people to rate 4,407 claims of common sense from multiple sources, including news media, political campaign emails, and popular sayings. These ranged from factual claims like “triangles have three sides” to the more abstract “perception is the only source of knowledge, what is not perceived does not exist” (#deep).

Participants were asked whether they agreed with a claim, why they answered the way they did, and how they thought most other people would answer. They also had to answer several other questions, such as whether or not they thought a claim was about physical or social reality and if it was an opinion or factual.

Overall, the team found that what’s perceived to be common sense varies considerably between people. That was less the case when it came to the facts, such as the number of sides in a triangle – although at this point, we wouldn’t be surprised to find a conspiracy theory claiming “Big Math” is lying to us about shapes.

When taking a closer look at the reasons for differences in people’s perception of common sense, it indicated that the way a person viewed a topic could have a significant impact on whether or not they felt something was common sense or not. For example, when it comes to the phrase “all people are created equal”, people who didn’t believe that were less likely to think of it as common sense. 


Someone’s level of social perception was also found to play a role, but perhaps most surprising, was that demographic factors such as age, education, and gender didn’t.

“We conclude that while there may exist a body of knowledge that is truly common to everyone, it constitutes only a fraction of what any one person considers to be common sense, where the latter is highly idiosyncratic and potentially unique to them alone,” the researchers write.

As for the uses of this research – other than letting us know we should probably be a tad more considerate the next time we’re about to bemoan someone for their lack of common sense – the team believes it has potential uses in both social science research and in the improvement of artificial intelligence.

The study is published in PNAS.


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