A bat and a ball cost $1. 10 in total. The bat costs $1. 00 more than the ball. How much does the ball cost?
If you answered 10 cents, you're not alone—most people give the same answer (the correct answer is 5 cents). It's an example of how we often rely on intuitive (直觉的) responses—answers we feel are true. People give answers that "pop into their mind, " says Steven Sloman. We don't spend much time "reflecting and checking whether the answer is right or wrong."
The bat and ball question helps explain why we often believe in fake news. It is part of human nature to believe, says Sloman. But "the trick with fake news is to know to verify" — in other words, to stop and question what you know. In one experiment, Sloman and a colleague invented a discovery called helium rain. They told a group of volunteers about it, but admitted they could not fully explain what it was. They then asked the volunteers to rate their own understanding of helium rain. Most volunteers rated themselves 1 out of 7, meaning they did not understand the concept.
The researchers then told another group of volunteers about the discovery. This time, they said that scientists could fully explain how it works. When asked to rate their understanding, the volunteers gave an average answer of 2. The scientists' confidence gave the volunteers an increased sense of their own understanding, Sloman says.
According to Sloman, studies show that knowledge spreads like a contagion(传染病). This idea can be seen in many fields, including politics. "If everyone around you is saying they understand why a politician is dishonest, " Sloman says, "then you're going to start thinking that you understand, too. "
Another explanation for the spread of fake news is "motivated reasoning, " writes Adam Wyatz, an American management professor, "we are naturally more likely to believe things that confirm our existing opinions. "
So in a world where misleading information is common, training people to care about fact-checking is important, especially in online communities. "We should check things and not just take them at face value," Sloman says. "Verify before you believe. "