The Uncommonality of Common Sense

It's far more idiosyncratic than we realized

Hiya!

I struggled continuously throughout my school years, but while my grades were less than ideal, I was repeatedly praised for my common sense. That’s probably why I’ve always been curious about it and am sometimes surprised by what others consider it to be. Because, if you think about it, common sense is pretty tricky to define.

On its surface level, common sense refers to knowledge or beliefs that are obvious to everyone, or should be. Yet, a more precise definition is oddly challenging to pin down. Even scientists have struggled to clarify it. In fact, it wasn’t until this year that anyone even tried to measure how common common sense really is or what qualifies as it — and they found that common sense isn’t common at all.

Our Reliance on Societial Common Sense

People have been advocating for common sense since at least the 18th century. Perhaps the most famous and influential arguments for common sense came on January 10, 1776, when political philosopher and writer Thomas Paine published his pamphlet literally titled Common Sense.

While initially published anonymously, the pamphlet laid out Paine’s arguments favoring American independence from the British. Within the first three months of publication, 120,000 copies of the pamphlet were sold, and by the end of the Revolutionary War (which lasted from 1775 to 1783), an estimated half-million copies were in circulation. Even today, Paine’s Common Sense pamphlet is considered one of the most influential pamphlets in American history.

The pamphlet promoted the idea of American exceptionalism and argued for forming a new nation to explore the country’s promise. In doing so, Common Sense attracted public support and pressured the rebellion’s leaders to declare independence. After the Revolutionary War and America’s victory over the British, some of Paine’s ideas wound up in the United States Bill of Rights and Constitution.

All these years later, common sense seems to make the world go round. It matters in everything from law and politics to health and parenting. Doctors and judges use common sense when issuing advice or making decisions about treatments or rulings that affect people’s lives — for better or worse. Politicians constantly advocate for “common-sense approaches” to societal problems, and parents frequently encourage children to use their common sense when making decisions — or scold them when they don’t.

Yet, incredibly, there is very little research into this everyday concept — which is why Penn Integrates Knowledge University Professor Duncan Watts at the University of Pennsylvania and Mark Whiting, a senior computational social scientist at the Computational Social Science Lab (CSSLab), decided to study common sense. They published their results in January 2024 in the Proceedings of the National Academy of Sciences.