Lazarsfeld was writing about "The American Soldier", a recently published study of over 600,000 servicemen, conducted by the research branch of the war department during and immediately after the second world war. To make his point, Lazarsfeld listed six findings that he claimed were representative of the report. Take number two: "Men from rural backgrounds were usually in better spirits during their Army life than soldiers from city backgrounds."
"Aha," says Lazarsfeld's imagined reader, "that makes perfect sense. Rural men in the 1940s were accustomed to harsher living standards and more physical labour than city men, so naturally they had an easier time adjusting. Why did we need such a vast and expensive study to tell me what I already knew?" Why indeed.
But Lazarsfeld then reveals the truth: all six of the "findings" were in fact the exact opposite of what the study found. It was city men, not rural men, who were happier during their army life. Of course, had the reader been told the real answers in the first place, they could just as easily have reconciled them with other things they already thought they knew: "City men are more used to working in crowded conditions and in corporations, with chains of command, strict standards of clothing, etiquette, and so on. That's obvious!" But this is exactly the point Lazarsfeld was making. When every answer and its opposite appears equally obvious then, as he put it, "something is wrong with the entire argument of 'obviousness'".
You should read the whole article, but in case you're feeling lazy, here's the conclusion:
Because of the way we learn from experiences - even ones that are never repeated - the failings of common sense reasoning are rarely apparent to us. Rather, they manifest simply as "things we didn't know at the time" but which seem obvious in hindsight.
The paradox of common sense, then, is that even as it helps us make sense of the world, it can actively undermine our ability to understand it.
