One of the most irritating things you can be told to do is ‘use your common sense’.
But the saying might not actually hold much weight, according to new research.
Experts have discovered that ‘common sense’, often claimed to be universal, is unique to each individual.
And what defines ‘common sense’ actually differs considerably from person to person.
The team, from the University of Pennsylvania, gathered 4,407 statements, each which – at some point – had been claimed to represent common-sense knowledge.
It might seem like common sense to some but researchers have found that people could not agree over whether ‘Planet Earth is round’ counted as commonsensical
Examples included ‘Triangles have three sides’, ‘A battery can’t provide power forever’, ‘Alcohol should be restricted for fans during sports games’, ‘Avoid close contact with people who are ill’, ‘If you want to play a guitar you should take lessons’ and ‘Planet Earth is round’.
They then asked more than 2,000 people to rate the extent to which they thought the claims were ‘commonsensical’.
They found that perception of which statements represented ‘common sense’ varied considerably between people.
And overall, relatively few statements satisfied the traditional definition of common sense, as ‘knowledge that is self-evident to all’, because not many people could agree on them.
The team said that, at most, only a small fraction of people agreed on which statements represented common sense.
The researchers found that people’s perception of whether statements like ‘A battery can’t provide power forever’ were self-evident varied widely, and very few statements met the criteria for common sense
Factors such as age and gender did not appear to influence how people perceived common sense, they added.
Writing in the journal Proceedings of the National Academy of Sciences, the researchers said: ‘Common sense, while often portrayed as universal, is paradoxically also often claimed not to exist.
‘Here, we resolve this puzzling situation by introducing a formal methodology to empirically quantify common sense both at individual and collective levels.
‘We show that common sense varies considerably across types of claims but aligns most closely with plainly worded, factual claims about physical reality.
‘We also find limited presence of collective common sense, undermining universalist claims and supporting sceptics.’
